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Agricultural Literacy Curriculum Matrix

Lesson Plans

A Recipe for Genetics: Selective Breeding and Transgenics

Purpose

Students will identify technologies that have changed the way humans affect the inheritance of desired traits in organisms; compare and contrast selective breeding methods to genetic engineering techniques; and analyze data to determine the best solution for cultivating selected desired traits in organisms.

Materials Needed

Interest Approach Activity 1 Activity 2 Activity 3 Concept Elaboration and Evaluation

Essential Files (maps, charts, pictures, or documents)

Vocabulary Words

agriculture: the science, art, or practice of cultivating the soil, producing crops, and raising livestock and in varying degrees the preparation and marketing of the resulting products

animal husbandry: the science of breeding and caring for farm animals

artificial selection: the intentional breeding of plants and animals to produce specific, desirable traits

domesticate: to breed a population of animals or plants to serve the purposes of human beings and to need and accept human care

gene: a section of DNA that contains the encoded instructions for making proteins

genetically engineered (GE): process of directly modifying an organism's genes using biotechnology to produce desired traits

genetically modified organism (GMO): any organism whose genetic material has been altered using genetic engineering techniques

selective breeding: a process by which humans use animal or plant breeding to selectively develop particular traits in an offspring; also known as artificial selection

transgenic: containing a gene that has been transferred from one organism to another and acts as a synonym for genetically modified

Did You Know? (Ag Facts)

Even though the process of artificial selection had been in use for centuries to create livestock and crops with desirable characteristics, Charles Darwin is credited with coining the term "artificial selection" in his book that he wrote upon returning from the Galapagos Islands.¹⁵

There is no substantiated evidence of a difference in risk to human health between current commercially available genetically modified (GM) crops and conventionally bred crops.⁵

Genetically modified (GM) crops in the United States are regulated by the Environmental Protection Agency (EPA), the Food and Drug Administration (FDA), and the United States Department of Agriculture (USDA).⁶

Background Agricultural Connections

The development of agriculture, or the intentional production of plants and animals for human use, allowed people to settle in one place and form villages and cities. Approximately 10,000 years ago, the domestication of plants and animals for human use began to develop rapidly. As hunter-gatherers became farmers, they learned to select and save seeds from plants that produced the best crops and to breed the animals that were best suited to meet people's needs. The first steps of domestication probably happened by accident, but soon farmers deliberately practiced selective breeding to develop crops and livestock more suited to their needs. 11 Selective breeding was likely the earliest form of biotechnology used by humans to improve the genetic characteristics of plants and animals. Biotechnology includes any use of science or technology to alter the genetic characteristics of a particular plant or animal. There are many examples of biotechnology. This lesson illustrates two- selective breeding and transgenesis.
Selective Breeding
Selective breeding (also known as artificial selection) is a technique still extensively used by crop and livestock producers today. Selective breeding allows producers to select and breed parent organisms with desired traits to produce offspring with more desirable characteristics. This process creates offspring who are genetically superior to the parent organisms, thus improving plants and animals with each generation. The successful results of selective breeding throughout the years can be seen in crop and livestock production today.

Many crops, including wheat, have been genetically improved through selective breeding. Dr. Norman Borlaug was a research scientist assigned to improve the wheat plant in Mexico. By studying genetics and utilizing selective breeding, he was able to develop short-strawed, disease-resistant wheat that was high yielding. Dr. Borlaug is known as the "Father of the Green Revolution" for his improvement of wheat and was awarded the Nobel Peace Prize for a lifetime of work to feed a hungry world. ⁴

In the livestock industry, today's cattle are also evidence of successful selective breeding. Dairy and beef cattle are both highly efficient animals that produce more milk and meat than in years past. Today, there are only 9 million dairy cows in the United States compared to 25 million cows in 1950; however, today's dairy cows are producing 60% more milk. ¹² In 1944, the average dairy cow produced 548 gallons of milk in one year. The average dairy cow today is able to produce 2,429 gallons of milk in one year. ¹³ Beef production has seen similar success. Compared to 1977, today's beef ranchers are producing the same amount of beef with 33% fewer cattle. ¹⁰ It is important to note that proper nutrition, better health care, and good animal husbandry also play a key role in improving genetics.
Transgenesis
Genetically modified organisms (GMOs) can also be referred to as genetically engineered (GE) or transgenic. These terms all describe an organism that has a copy of a gene not previously found in that species.

A genetically modified crop is a crop that has had its genetic makeup altered in order to produce a more desirable outcome, such as resistance to disease, drought tolerance, or change in size. 1 This type of plant breeding differs from selective breeding because scientists take the desirable gene from one organism's DNA and transfer it to another organism's DNA, creating a new, stronger product-one that is impossible to produce through traditional breeding. ¹

Currently, there are ten genetically modified crops that have been approved and are available on the U.S. market: corn, soybeans, cotton, canola, sugar beets, alfalfa, papaya, squash, apples, and potatoes. To learn more about the safety and regulatory process of GM crops refer to the Background Agricultural Connections section of the lesson plan, Evaluating GMO Perspectives.

Interest Approach - Engagement

1. Begin by asking students to think about the food they eat.

Has our food always looked the same?

How has food changed over the years?

Why has food changed?

2. Project the Then and Now PowerPoint on the board.

3. Show slides 2-9 to the students. Allow students to look at the ancient/wild varieties of food and guess what it is. (e.g. wild banana, wild watermelon, ancient carrot and corn).

4. When students compare the older foods to today's foods, ask them to point out visible differences including size, shape, color, and the amount of edible flesh. Ask them how they think the taste would compare.

5. Project slide 10 on the board and ask students, "What has caused these traits to change?" Lead students to use their existing knowledge to explain what they can about how humans have influenced the look and taste of bananas, carrots, corn, and watermelon? (Through selective breeding.)

6. Project slide 11 on the board. Ask students to think about animal traits. Have humans influenced animal traits and genetics? (Yes, by selecting plants and animals with desired traits and breeding those animals to produce offspring with the desired traits.)

7. Explain to students that they will discover two methods used by agriculturists and scientists to improve the genetics and traits of the food we eat.

Procedures

Activity 1: A Recipe for DNA

1. Divide the class into six groups.

2. Pass out a recipe card to each group.
Note: The class can also be divided into smaller groups and two copies of each recipe can be distributed if smaller groups would be more ideal for your class.

3. Instruct students to read through the ingredients and baking instructions on their recipe card. Ask, "If you were to follow the instructions on your recipe, what product will you end up with?" (Each recipe is for a type of cookie.)

4. Allow each group to share their recipe guesses with the class.

5. Show students the type of cookie each of their recipes make using the Cookie Key image.

6. Ask students:

Why would each of you end up with a different cookie?" (While each recipe has some similar ingredients, it also includes different ingredients and instructions for mixing and baking resulting in a different type of cookie.)

Are there any improvements that could be made to your recipes? (Yes, depending on what kind of cookie you want.)

Could you alter your recipes? (Yes, ingredients could be substituted with other baking alternatives, ingredients could be taken out due to food allergies or intolerance, or ingredients could be added to obtain a desired outcome of some sort.)

7. Now ask the students to think about their cookie recipes and relate it to what they know about DNA. Ask:

What is DNA?

How can the DNA in living organisms relate to a cookie recipe? (DNA contains "ingredients" and a set of instructions for living organisms. DNA determines the genetic material and outcome of each living organism.)

Can we improve or alter the DNA of plants and animals? (Yes, through selective breeding and genetic engineering.)

8. Show students theimage, A Recipe for DNA and explain that our DNA is made of different "ingredients" including a sugar phosphate backbone, nitrogenous bases, and hydrogen bonds. Explain to students that adenine (A) always pairs with thymine (T) and cytosine (C) always pairs with guanine (G). The order in which these nitrogenous bases line up acts as a set of instructions for DNA that determines the characteristics and traits in all living organisms.

9. Explain to students that our basic knowledge of DNA and genetic inheritance has allowed humans to influence the genetic traits of plants and animals.

Activity 2: Selective Breeding

1. Show the video, Natural Selection vs Artificial Selection.

2. Following the video, make a Venn Diagram with students to identify the similarities and differences between natural selection and artificial selection (also known as selective breeding). If helpful, display the Natural Selection vs Artificial Selection Venn Diagram.
Tip: Be sure students recognize that the terms artificial selection and selective breeding are synonymous.

3. Set up four different stations around the classroom using the Selective Breeding Station Cards.

4. Divide the class into four groups and assign each group a specific station around the classroom.
Note: A second set of station cards can be printed so students are in smaller groups.

5. Pass out one Selective Breeding handout to each student.

6. Explain to students that they will be rotating through 4 stations. They will have approximately 5 minutes at each station to read the station card instructions, background information, and scenario.

7. Set a timer. Consider projecting the timer in the classroom to allow students to gauge their time at each station. Adjust the time limit as necessary. After time is up, groups should rotate to the next station until all four stations have been visited.

8. Bring the class back together to discuss each of the stations.

9. Allow students to share their thoughts and answers for each of the stations.

Which animals did they select for breeding purposes?

How does selective breeding (artificial selection) benefit livestock producers?

How do these selective breeding scenarios affect us?

10. Discuss each of the following scenarios with students.

Milk Production

Which cows did you select and why? (Ideally, students should have selected the cows 6, 5, 2, and 3)

How does selective breeding in the dairy industry affect us as consumers? (Dairy producers are not only selecting healthy livestock but breeding and improving traits that directly affect our food supply. The milk produced on dairies is used to make many products including cheese, yogurt, butter, sour cream, and ice cream.)

Butterfat Content
Which Jersey cows did students select to maintain a high butterfat content in the herd? (Ideally, students should have selected the cows 1, 4, 3, and 2)

Birthweight and Weaning Weight
Which Angus bull has a low birthweight for small cows, but high weaning weight? Will some students sacrifice a low birthweight to have a very high weaning weight? Remind students that when beef producers sell the calves in the fall, they are paid by the pound, so high weaning weights mean more money. However, calves born at 90-100 pounds can cause problems at birth for heifers and small cows. Ideally, bull 1 with an 80-pound birthweight will still give producers a large calf at weaning.)

Horned and Polled Cattle
Which cows should be selected to ensure no offspring have horns? (Cows 3, 4 and 5. When using a horned bull with a genotype (pp), cows with the genotype (PP) should be selected for breeding. (pp) x (PP) = (Pp) The bull will always pass on a recessive horned gene (p) to his offspring, so if you cross a horned bull (pp) with a heterozygous cow (Pp), there is a chance for horned offspring. Breeding the horned bull (pp) with the horned cow (pp) will give producers a 100% chance of having horned offspring.

11. Now ask students what other technologies or management practices can affect desired traits in livestock. Explain that proper care and animal husbandry can help maintain desired traits and genetics. Close monitoring of animal health, proper nutrition, shelter, and waste management all affect livestock production. A calf may be born with superior genetics, but if it is not taken care of properly or fed correctly, inherited traits may be negatively affected.

12. To transition into Activity 3, ask students, "What does it mean if an organism is genetically modified?" Allow students to answer or brainstorm ideas.

Activity 3: GMO Issues, Solutions, and Results

1. Divide the class into groups of four students.

2. Start by passing out a set of GMO Issues cards to each group.

3. Instruct groups to read through each of the cards. Explain that each card describes a challenge.

4. Discuss each of the issues as a class. Consider asking students the following questions to lead a class discussion:

Are you familiar with any of these issues related to the production of our food and fiber?

What are the negative impacts of these issues? (food waste, malnutrition, inefficient use of natural resources like water and soil nutrients, reduced production of food and fiber that humans need.)

Who is affected by these issues? (Farmers and consumers, so everyone.)

Can any of the issues be resolved? (Yes.)

5. Ask students to brainstorm possible solutions. Prompt students to think about what they have learned about selective breeding. What limitations would selective breeding present?

6. Next, pass out a set of GMO Solutions cards to each group of students.

7. Instruct students to read through the solutions and match each of the solutions to an issue.

8. Pass out a set of GMO Results cards to each group of students. (This will be their third and final set of cards.)

9. Instruct students to match each of the results to the issues and solutions cards. Each match should include one GMO issue, solution, and result.

10. Discuss each of the GMO cards. Explain that there are currently 10 genetically modified crops available on the U.S. market.

An important point of science and agricultural literacy is for students to recognize which crops in the United States have a genetically modified variety available for farmers to grow. Grocery stores contain many, many foods with a "non-GMO" label that do not actually have a GMO variety. This leads to the misconception that many or most foods on the market are GMOs.

1. For a brief explanation of the process of creating a GMO, watch How Are GMOs Made? The Genetically Modified Hawaiian Papaya Case Study.

2. Summarize by explaining that genetically modified organisms (GMOs) are created using a scientific process called transgenesis which refers to the process of transferring a gene from one organism to another with the intent of acquiring a new genetic trait.

Concept Elaboration and Evaluation

1. After conducting these activities students should be able to identify similarities and differences between selective breeding and transgenesis. Draw a Venn Diagram on the board labeling one circle "Selective Breeding" and the other circle "Transgenesis."

2. Pass out the Venn Diagram Prompts to various students in the class and have them add the strip of paper to the correct portion of the diagram. Discuss and provide clarification as needed.

3. Review and summarize the following key concepts with your students:

DNA makes up the instructions for all living things.

Humans can influence the inheritance of traits by selecting only parents that have desired traits through a process called selective breeding (also known as artificial selection).

Technology can increase our ability to select and perpetuate helpful genetic traits in the plants and animals that provide our food. Transgenics is one example.

Suggested Companion Resources

Organization Affiliation

Utah Agriculture in the Classroom

We welcome your feedback. Please take a minute to share your thoughts on this lesson.

Agricultural Literacy

Education Content Standards

Common Core Connections

Education Content Standards

Science (SCIENCE)

MS-LS4 Biological Evolution: Unity and Diversity

MS-LS4-5 Gather and synthesize information about technologies that have changed the way humans influence the inheritance of desired traits in organisms.

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Sue Knott, Administrator and Yasuko Mitsuoka Grow, Designer

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A Recipe for Genetics: Selective Breeding and Transgenics

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Students will identify technologies that have changed the way humans affect the inheritance of desired traits in organisms; compare and contrast selective breeding methods to genetic engineering techniques; and analyze data to determine the best solution for cultivating selected desired traits in organisms.

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Student Project: Make a Scale Solar System | NASA/JPL Edu

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Use beads and string, sidewalk chalk, or your own creative choice of materials to build a scale model of planet sizes or distances in the solar system.

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Quick Look

Grade Level: 7 (6-8)

Time Required: 30 minutes

Lesson Dependency: None

Subject Areas: Physical Science, Physics

NGSS Performance Expectations:

Summary Students explore the physics exploited by engineers in designing today's roller coasters, including potential and kinetic energy, friction and gravity. First, they learn that all true roller coasters are completely driven by the force of gravity and that the conversion between potential and kinetic energy is essential to all roller coasters. Second, they consider the role of friction in slowing down cars in roller coasters. Finally, they examine the acceleration of roller coaster cars as they travel around the track. During the associated activity, students design, build and analyze model roller coasters they make using foam tubing and marbles (as the cars).
This engineering curriculum aligns to Next Generation Science Standards (NGSS).

Engineering Connection

Students explore the most basic physical principles of roller coasters, which are crucial to the initial design process for engineers who create roller coasters. They learn about the possibilities and limitations of roller coasters within the context of energy conservation, frictional losses and other physical principles. After the lesson, students should be able to analyze the motion of any existing gravity-driven coaster and design the basics of their own model roller coasters.

Learning Objectives

After this activity, students should be able to:

Explain why it is important for engineers to know how roller coasters work.

Explain in physics terms how a roller coaster works.

Discuss the effects of gravity and friction in the context of their roller coaster designs.

Use the principle of conservation of energy to explain the layout of roller coasters.

Identify points in a roller coaster track at which a car has maximum kinetic energy and maximum potential energy.

Identify points in a roller coaster track where a car experiences more or less than 1 g-force.

Identify points in a roller coaster track where a car accelerates and decelerates.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS Performance Expectation

Click to view other curriculum aligned to this Performance Expectation

This lesson focuses on the following Three Dimensional Learning aspects of NGSS:

Science & Engineering Practices

Disciplinary Core Ideas

Crosscutting Concepts

Science knowledge is based upon logical and conceptual connections between evidence and explanations.

When the motion energy of an object changes, there is inevitably some other change in energy at the same time.

Energy may take different forms (e.g. energy in fields, thermal energy, energy of motion).

Suggest an alignment not listed above

Pre-Req Knowledge

An understanding of forces, particularly gravity and friction, as well as some familiarity with kinetic and potential energy. An understanding of Newton's second law of motion and basic motion concepts such as position, velocity and acceleration.

Introduction/Motivation

Today's lesson is all about roller coasters and the science and engineering behind them. Before we start talking about physics, though, I'd like you to share some of your experiences with roller coasters. (Listen to a few students describe their favorite roller coasters. Point out some of the unique features of each coaster, such as hills and loops, that relate to the lesson.)

Does anyone know how roller coasters work? You might think that the roller coaster cars have engines inside them that push them along the track like automobiles. While that is true of a few roller coasters, most use gravity to move the cars along the track. Do any of you remember riding a roller coaster that started out with a big hill? If you looked closely at the roller coaster track (on which the cars move), you would see in the middle of the track on that first hill, a chain. You might have even have felt it "catch" to the cars. That chain hooks to the bottom of the cars and pulls them to the top of that first hill, which is always the highest point on a roller coaster. Once the cars are at the top of that hill, they are released from the chain and coast through the rest of the track, which is where the name roller coaster comes from.

Figure 1. Example setup for quick lesson demo.

What do you think would happen if a roller coaster had a hill in the middle of the track that was taller than the first hill of the roller coaster? Would the cars be able to make it up this bigger hill using just gravity? (Conduct a short demonstration to prove the point. Take a piece of foam pipe insulation cut in half lengthwise and shape it into a roller coaster by taping it to classroom objects such as a desktop and a textbook, as shown in Figure 1. Then, using marbles to represent the cars, show students that the first hill of a roller coaster must be the tallest point or the cars will not reach the end of the track. Refer to the Building Roller Coasters activity for additional instructions.)

(Next, play off other students' roller coaster experiences to move the lesson forward, covering the material provided in the Lesson Background and Vocabulary sections. For example, talk about the point in the roller coaster where you travel the fastest, how cars make it through loops and corkscrews, and what causes passengers to feel weightless or very heavy at certain points in the roller coaster. The order in which you teach these points, and possibly more, is not critical to the lesson. Also, it may be more engaging for the students to ask questions based on their experiences with roller coasters and let those questions lead the lesson from one point to the next. All of these points can be demonstrated using the foam tubing and marbles, so use them often to illustrate the lesson concepts.)

Lesson Background and Concepts for Teachers

The underlying principle of all roller coasters is the law of conservation of energy, which describes how energy can neither be lost nor created; energy is only transferred from one form to another. In roller coasters, the two forms of energy that are most important are gravitational potential energy and kinetic energy. Gravitational potential energy is the energy that an object has because of its height and is equal to the object's mass multiplied by its height multiplied by the gravitational constant (PE = mgh). Gravitational potential energy is greatest at the highest point of a roller coaster and least at the lowest point. Kinetic energy is energy an object has because of its motion and is equal to one-half multiplied by the mass of an object multiplied by its velocity squared (KE = 1/2 mv ²). Kinetic energy is greatest at the lowest point of a roller coaster and least at the highest point. Potential and kinetic energy can be exchanged for one another, so at certain points the cars of a roller coaster may have just potential energy (at the top of the first hill), just kinetic energy (at the lowest point) or some combination of kinetic and potential energy (at all other points).

The first hill of a roller coaster is always the highest point of the roller coaster because friction and drag immediately begin robbing the car of energy. At the top of the first hill, a car's energy is almost entirely gravitational potential energy (because its velocity is zero or almost zero). This is the maximum energy that the car will ever have during the ride. That energy can become kinetic energy (which it does at the bottom of this hill when the car is moving fast) or a combination of potential and kinetic energy (like at the tops of smaller hills), but the total energy of the car cannot be more than it was at the top of the first hill. If a taller hill were placed in the middle of the roller coaster, it would represent more gravitational potential energy than the first hill, so a car would not be able to ascend to the top of the taller hill.

Cars in roller coasters always move the fastest at the bottoms of hills. This is related to the first concept in that at the bottom of hills all of the potential energy has been converted to kinetic energy, which means more speed. Likewise, cars always move the slowest at their highest point, which is the top of the first hill.

A web-based simulation demonstrating the relationship between vertical position and the speed of a car in a roller coaster various shapes is provided at the MyPhysicsLab Roller Coaster Physics Simulation. This website provides numerical data for simulated roller coaster of various shapes.

Friction exists in all roller coasters, and it takes away from the useful energy provided by roller coaster. Friction is caused in roller coasters by the rubbing of the car wheels on the track and by the rubbing of air (and sometimes water!) against the cars. Friction turns the useful energy of the roller coaster (gravitational potential energy and kinetic energy) into heat energy, which serves no purpose associated with propelling cars along the track. Friction is the reason roller coasters cannot go on forever, so minimizing friction is one of the biggest challenges for roller coaster engineers. Friction is also the reason that roller coasters can never regain their maximum height after the initial hill unless a second chain lift is incorporated somewhere on the track.

Cars can only make it through loops if they have enough speed at the top of the loop. This minimum speed is referred to as the critical velocity, and is equal the square root of the radius of the loop multiplied by the gravitational constant (v c = (rg) 1/2). While this calculation is too complex for the vast majority of seventh graders, they will intuitively understand that if a car is not moving fast enough at the top of a loop it will fall. For safety, most roller coasters have wheels on both sides of the track to prevent cars from falling.

Most roller coaster loops are not perfectly circular in shape, but have a teardrop shape called a clothoid. Roller coaster designers discovered that if a loop is circular, the rider experiences the greatest force at the bottom of the loop when the cars are moving fastest. After many riders sustained neck injuries, the looping roller coaster was abandoned in 1901 and revived only in 1976 when Revolution at Six Flags Magic Mountain became the first modern looping roller coaster using a clothoid shape. In a clothoid, the radius of curvature of the loop is widest at the bottom, reducing the force on the riders when the cars move fastest, and smallest at the top when the cars are moving relatively slowly. This allowed for a smoother, safer ride and the teardrop shape is now in use in roller coasters around the world.

Riders may experience weightlessness at the tops of hills (negative g-forces) and feel heavy at the bottoms of hills (positive g-forces). This feeling is caused by the change in direction of the roller coaster. At the top of a roller coaster, the car goes from moving upward to flat to moving downward. This change in direction is known as acceleration and the acceleration makes riders feel as if a force is acting on them, pulling them out of their seats. Similarly, at the bottom of hills, riders go from moving downward to flat to moving upward, and thus feel as if a force is pushing them down into their seats. These forces can be referred to in terms of gravity and are called gravitational forces, or g-forces. One "g" is the force applied by gravity while standing on Earth at sea level. The human body is used to existing in a 1 g environment. If the acceleration of a roller coaster at the bottom of a hill is equal to the acceleration of gravity (9.81 m/s ²), another g-force is produced and, when added to the standard 1 g, we get 2gs. If the acceleration at the bottom of the hill is twice the acceleration of gravity, the overall force is 3 gs. If this acceleration acts instead at the top of a hill, it is subtracted from the standard 1 g. In this way, it can be less than 1 g, and it can even be negative. If the acceleration at the top of a hill were equal to the acceleration of gravity, the overall force would be zero gs. If the acceleration at the top of the hill were twice the acceleration of gravity, the resulting overall force would be negative 1 g. At zero gs, a rider feels completely weightless and at negative gs, they feel as though a force is lifting them out of the seat. This concept may be too advanced for students, but they should understand the basic principles and where g-forces greater than or less than 1 g can occur, even if they cannot fully relate them to the acceleration of the roller coaster.

Associated Activities

Vocabulary/Definitions

acceleration: How quickly an object speeds up, slows down or changes direction. Is equal to change in velocity divided by time.

critical velocity: The speed needed at the top of a loop for a car to make it through the loop without falling off the track.

force: Any push or pull.

friction: A force caused by a rubbing motion between two objects.

g-force: Short for gravitational force. The force exerted on an object by the Earth's gravity at sea level.

gravitational constant: The acceleration caused by Earth's gravity at sea level. Is equal to 9.81 m/sec^2 (32.2 ft/sec^2).

gravity: A force that draws any two objects toward one another.

kinetic energy: The energy of an object in motion, which is directly related to its velocity and its mass.

potential energy: The energy stored by an object ready to be used. (In this lesson, we use gravitational potential energy, which is directly related to the height of an object and its mass.)

speed: How fast an object moves. The distance that object travels divided by the time it takes.

velocity: A combination of speed and the direction in which an object travels.

Assessment

Pre-Lesson Assessment

Before the lesson, make sure students have a firm handle on gravity, friction, potential and kinetic energy, and the basics of motion. This can be done in the form of a short quiz, a warm-up exercise or a brief discussion. Example questions:

What causes gravity?

What is friction?

How do potential and kinetic energy differ?

What is the difference between speed and velocity?

How is acceleration related to velocity?

Lesson Summary Assessment

Show students a photograph of a roller coaster that includes a hill and a loop. Expect them to be able to identify:

Points of maximum potential and kinetic energy.

Points of maximum and minimum velocity.

Points where g-forces greater or less than 1 are experienced.

Homework

Ask students to design their own roller coasters or find an existing roller coaster on the Internet and identify its characteristics in terms of the physics concepts learned in the lesson. This assignment also serves as an introduction to the associated activity, Building a Roller Coaster.

References

Bennett, David. Roller Coaster. Aurum Ltd., 1999.

Roller Coaster Database. Copyright 1996-2007. Duane Marden. Accessed 5/3/2007. http://www.rcdb.com/

Funderstanding Roller Coaster. Copyright 1998. Funderstanding. Accessed 5/3/2007. http://www.funderstanding.com/k12/coaster/

Loop (Roller Coaster). Last modified April 9, 2007. Wikipedia. Accessed 5/3/2007. http://en.wikipedia.org/wiki/Loop_%28roller_coaster)

Pescovitz, David. Roller Coaster Physics. Copyright 1998-1999. Encyclopedia Britannica, Inc. Accessed 5/3/2007. http://search.eb.com/coasters/ride.html

Neumann, Erik. Roller Coaster Physics Simulation. Copyright 2004. MyPhysicsLab. Accessed 5/3/2007. http://www.myphysicslab.com/RollerSimple.html

Other Related Information

Browse the NGSS Engineering-aligned Physics Curriculum hub for additional Physics and Physical Science curriculum featuring Engineering.

Copyright © 2013 by Regents of the University of Colorado; original © 2007 Duke University

Contributors Scott Liddle

Supporting Program Engineering K-PhD Program, Pratt School of Engineering, Duke University

Acknowledgements

This content was developed by the MUSIC (Math Understanding through Science Integrated with Curriculum) Program in the Pratt School of Engineering at Duke University under National Science Foundation GK-12 grant no. DGE 0338262. However, these contents do not necessarily represent the policies of the NSF, and you should not assume endorsement by the federal government.

Last modified: November 16, 2022

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Students explore the physics exploited by engineers in designing today's roller coasters, including potential and kinetic energy, friction and gravity. First, they learn that all true roller coasters are completely driven by the force of gravity and that the conversion between potential and kinetic energy is essential to all roller coasters.

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Discussion and Supporting Materials

Thought starters

1. How does "chiming" benefit both the teacher and students?

2. Why does having more constraints make students better problem solvers?

3. What strategies does Ms. Migdol use to get all students engaged in this project?

Teachers

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Fifth graders in Donna Migdol's class work collaboratively to create a roller coaster with the longest ride so that a marble can get to end of the roller coaster without falling off. The class begins by "chiming," talking about their design ideas and building off of each other's thoughts.

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McClure, Jill - STEM 7/8 / Paper Rollercoaster Project

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Mad River Local Schools is an equal opportunity employer and complies with all Federal and Ohio State laws, regulations, and executive orders regarding non-discrimination. Applicants are considered for all positions without regard to race, color, religion, sex (including gender identity, sexual orientation, and pregnancy), national origin, age, disability, or genetic information.

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MS-ESS1-1

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MS-ESS1-1 Evidence Statements June 2015.pdf

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Moon Phases & Eclipses is a free and innovative 3-day unit that provides interactive videos, hands-on activities, lesson plans, and student worksheets to explore why the Moon's phase changes. The curriculum uses a combination of Earth- and space-based visualizations and models to address common misconceptions and strengthen students' spatial reasoning skills. Moon Phases & Eclipses is aligned with standards for middle school Earth and Space Science (NGSS MS-ESS1-1).

The program covers the rotation and revolution; the relationship between sunlight and the objects in our solar system; the different phases of the lunar cycle; and a four-step process for predicting an Earth-based perspective of the Moon's phase. Join us as we use WorldWide Telescope to journey around the solar system to better understand Moon Phases as seen from Earth!

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Moon Phases & Eclipses is a free and innovative 3-day unit that provides interactive videos, hands-on activities, lesson plans, and student worksheets to explore why the Moon's phase changes. The curriculum uses a combination of Earth- and space-based visualizations and models to address common misconceptions and strengthen students' spatial reasoning skills.

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Overview Since 1998, NASA's Solar System Exploration hub has served as a real-time, living encyclopedia of the scientific exploration of our solar system. We provide reliable, accurate, up-to-date information about the planets, moons, asteroids, comets, and everything else in our solar system and the spacecraft that explore them.

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Our solar system was doing just fine without humanity for 99.995% of its lifetime

Our Solar System is quite "young", at least as far as solar systems go. Using radiometric dating, scientists were able to determine that most of its ingredients, including the sun and the planets, are just over 4.6 billion years old (while one of the oldest stars detected is a ripe 13.6 billion years old.) By comparison, humans have been around for a "mere" 200 thousand years, a barely noticeable spec in the vastness of Solar System's lifespan.

Our Sun contains 99.86% of the Solar System's known mass

The mass of the Sun is 1.989 × 10 ³⁰ kg when all the planets combined are only 2.66 x 10 ²⁷ kg.

The hottest planet is actually not the one closest to the sun

Although Mercury is the planet nearest to the Sun, it's actually only the second hottest planet, following Venus. Why? Mercury is tiny and doesn't have any atmosphere, which under normal circumstances traps and holds heat. Any heat that Mercury receives from the sun quickly dissipates back into space. Venus on the other hand is very close in size to Earth and viewing it has been difficult due to a very thick atmosphere of carbon dioxide. This thick atmosphere, coupled with its close proximity to the sun, makes the surface of Venus hotter because the heat has a harder time escaping back into space.

Pluto is smaller than the USA

USA

Horizontal Width: 2,680 miles

Vertical Length: 1,582 miles

vs

Pluto

Radius: 736.9 mi

We are all citizens of the Sun

Planets can be categorized into 3 groupings, each at different proximity to the sun

The inner planets (also known as terrestrial planets) are smaller and made primarily of rock and metal.

The outer planets can be further categorized into two sub-classes - gas giants and ice giants. These are much larger and further away from the sun:

The gas giants primarily consist of lighter gasses, higher up on the periodic table (e.g. H and He.)

The ice giants contain gases heavier than those that make up gas giants, e.g. O, C, N, S and located at the outer rim of our solar system.

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Our solar system was doing just fine without humanity for 99.995% of its lifetime Our Solar System is quite "young", at least as far as solar systems go. Using radiometric dating, scientists were able to determine that most of its ingredients, including the sun and the planets, are just over 4.6 billion years old (while one of the oldest stars detected is a ripe 13.6 billion years old.)

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Calculate local times for sunrises, sunsets, meridian passing, Sun distance, altitude and twilight, dusk and dawn times.

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Can wildlife adapt to climate change? - Erin Eastwood

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Have you ever wondered when the next full moon will be? How about the first quarter moon? Now you can have all the dates and times for all the moon phases for the year at your fingertips by building your own moon phases calendar and calculator!

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Student Project: Make a Moon Phases Calendar and Calculator - New for 2024 | NASA/JPL Edu

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Like a decoder wheel for the Moon, this calendar will show you where and when to see the Moon and every moon phase throughout the year. 2024 calendar now available!

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Smithsonian National Air and Space Museum

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Middle School: Understanding White Sharks | Next Generation Science Standards

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Numerous reports suggest an increase in white shark encounters in the United States in recent years and the public is worried. In this integrated middle school unit, students engage in three-dimensional learning that enables them to explain the phenomenon. White sharks in the coastal waters of Southern California serve as a case study for students to ask questions and build understanding.

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HHMI's BioInteractive - Click and Learn - Sorting Finch Species

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Pages from 8.3.1 SCALE Task 1 Rock Sample Task Card.pdf

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8.3.1 SCALE Task 1 Mass Extinctions Reading.pdf

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Scroll to the side to see more columns.  Scroll down to view more resources in a column.

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Scroll to the right for additional resources! 

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Scroll to the right for additional resources! 

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A Pleistocene Puzzle: Extinction in South America

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In this comic, you'll follow the investigation of scientists Maria and Miguel as they solve a paleontological mystery. About 11,000 years ago, more than 80% of the large animal species in South America went extinct. Why did it happen? Maria and Miguel study an area in Chile called Ultima Esperanza.

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Slides

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8.3.1 SCALE Task 1: Fossil Record and Geologic Time Scale Slides.pdf

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Student Handout

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8.3.1 SCALE Task 1 Fossil Record and Geologic Timescale Student Resrouce.pdf

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Lesson Plan

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Slides

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8.3.0 Lift Off Task Culminating Project Intro Slides.pdf

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IS 3 Evolution Explains Life's Unity and Diversity.pdf

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Unit 3 Student Version - 8th Grade Integrated .pdf

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Unit 3 Teacher Version - 8th Grade Integrated .pdf

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Nature's Masters Of Disguise | Maddie About Science

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Good Thinking! – Natural Selection: Common Misconceptions

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Natural Selection: Common Misconceptions — reveals common pitfalls in the teaching of evolution through natural selection and suggests effective practices for identifying and addressing student misconceptions.

Explore the research:  http://s.si.edu/1IwH5zS
Credits: http://s.si.edu/1SGMX0J    

----

If you enjoyed our Good Thinking! videos, share them with a friend, colleague, or a teacher in your life. And be sure to connect with us online!
 
Our Website:  http://s.si.edu/1RtrHsO 
STEMVisions Blog:  http://s.si.edu/1de3GIH 
 
Facebook:  http://s.si.edu/1Hc9Rt0 

Twitter:  http://s.si.edu/1GmsSVR 

Pinterest:  http://s.si.edu/IJtdLq 

Google+:  http://s.si.edu/1SGMzzj

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Explore: Science based arguments relating to GMO's

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Explore: Science based arguments relating to GMO's

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Food Evolution - Narrated by Neil deGrasse Tyson

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Do alternative facts and fake news enrage you as much when the topic is...food? Food Evolution - in theaters this summer.

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The Arthropod Story takes you on a tour through the amazing evolutionary history of arthropods. Along the way, you'll get a healthy dose of taxonomy, paleontology, natural history and principles of evolution. You can start at the beginning or pick a section from this list:

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Introduction to the Solar System: Crash Course Astronomy #9

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This 6th, 7th, and 8th grade curriculum aligns to the California Integrated model in which earth and space science, life science, physical science and/or engineering are integrated within each curriculum unit.

All the units:

are project-based

include Instructionally embedded assessments

align to the 5E instructional model (i.e., engage, explore, explain, elaborate, evaluate)

are phenomena-based

provide students with opportunities to generate their own questions to motivate sense-making and/or problem solving

incorporate language development strategies

provide an additional pop-out lesson that allows students to apply what they've learned to delve deeper into the intersection of social justice, science, and the "greater good" (see "Pop-Outs" tabs)

In addition to our four instructional units, there is a unit devoted to groupwork to help teachers establish classroom norms and expectations around effective collaborative work.

6th Grade Curriculum 7th Grade Curriculum 8th Grade Curriculum

* For updated versions and additions to the curriculum, sign up for announcements from the SCALE Science team by contacting us through the Contact Us botton at the bottom of the page.

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Stanford NGSS Integrated Curriculum: An Exploration of a Multidimensional World

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Integrated, NGSS-designed, project-based curriculum for 6th, 7th, and 8th grades. This 6th, 7th, and 8th grade curriculum aligns to the California Integrated model in which earth and space science, life science, physical science and/or engineering are integrated within each curriculum unit. All the units: are project-based

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This 6th, 7th, and 8th grade curriculum aligns to the California Integrated model in which earth and space science, life science, physical science and/or engineering are integrated within each curriculum unit.

All the units:

are project-based

include Instructionally embedded assessments

align to the 5E instructional model (i.e., engage, explore, explain, elaborate, evaluate)

are phenomena-based

provide students with opportunities to generate their own questions to motivate sense-making and/or problem solving

incorporate language development strategies

provide an additional pop-out lesson that allows students to apply what they've learned to delve deeper into the intersection of social justice, science, and the "greater good" (see "Pop-Outs" tabs)

In addition to our four instructional units, there is a unit devoted to groupwork to help teachers establish classroom norms and expectations around effective collaborative work.

6th Grade Curriculum 7th Grade Curriculum 8th Grade Curriculum

* For updated versions and additions to the curriculum, sign up for announcements from the SCALE Science team by contacting us through the Contact Us botton at the bottom of the page.

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Stanford NGSS Integrated Curriculum: An Exploration of a Multidimensional World

# data[].attributes.attachment_link.description
Integrated, NGSS-designed, project-based curriculum for 6th, 7th, and 8th grades. This 6th, 7th, and 8th grade curriculum aligns to the California Integrated model in which earth and space science, life science, physical science and/or engineering are integrated within each curriculum unit. All the units: are project-based

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Simulations and animations for astronomy. Seasons simulator, Lunar phases simulator... Provides NASA HD Photo of the Day, Save photos to Google Drive directly.

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This resource was created to provide resources to teachers in the transition to NGSS. This resource bank continues to grow and evolve on a daily basis.

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Resources are organized according to the CA Science Framework Integrated MS model.

Nomenclature: A.B.C
A = Grade
B = Instructional Segment in CA Framework
C = Module as created by TCOE

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Many people believe that Earth is closest to the sun in summer and farthest in winter...
SAY WHAT?!

Although this idea makes sense, it is incorrect.

It is true that Earth's orbit is not a perfect circle. It is slightly elongated, so that during part of the year, Earth is closer to the sun than at other times. However, in the Northern Hemisphere, we are having winter when Earth is closest to the sun and summer when it is farthest away!

There is a completely different reason for Earth's seasons.

Earth has seasons because sometime early in its long history, something very big hit the young Earth to knock it off-kilter. So instead of rotating with its axis perpendicular to its orbital plane, it is tilted 23.45 degrees from the perpendicular.

Incidentally, that big something that hit Earth also knocked a chunk of it out that became our Moon. At least that is generally accepted theory.

So, here we are, orbiting the sun, but tilted a bit and always with the axis pointed in the same direction. So different parts of Earth get the sun's direct rays as we travel through the year.

Thus, sometimes it is the North Pole tilting toward the sun (like in June) and sometimes it is the South Pole tilting toward the sun (like in December). Hence, the seasons. It is summer in June in the Northern Hemisphere because the sun's rays hit that part of Earth more directly than at any other point in Earth's orbit - or, in other words, more directly than at any other time of the year. It is winter in December in the Northern Hemisphere, because that is when it is the South Pole's turn to be tilted toward the sun.

It follows that if you live in North America, during the winter the sun's path across the sky is more toward the south, rising in the southeast and setting in the southwest. During the summer, the sun tracks more directly overhead, rising in the east, overhead at noon, and setting in the west. If you live in the Southern Hemisphere, the sun will be more northerly in the sky during the winter (that is, June, July, and August).

So if you go to South Africa for the winter holidays, bring your swimsuit and leave your skis at home.

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Many people believe that Earth is closest to the sun in summer and farthest in winter...SAY WHAT?! Although this idea makes sense, it is incorrect. It is true that Earth's orbit is not a perfect circle. It is slightly elongated, so that during part of the year, Earth is closer to the sun than at other times.

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Teacher Version - 8th Grade Integrated .pdf

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Plate tectonics and evidence of evolution

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Plate tectonics and evidence of evolution

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What could you possibly have in common with a mushroom, or a dinosaur, or even a bacterium? More than you might think. In this Lab, you'll puzzle out the evolutionary relationships linking together a spectacular array of species. Explore the tree of life and get a front row seat to what some have called the greatest show on Earth. That show is evolution.

BUILD A TREE & DEEP TREE ACTIVITIES
DEVELOPED BY THE LIFE ON EARTH PROJECT

Video Intro About this Lab Educator Guide

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What could you possibly have in common with a mushroom, or a dinosaur, or even a bacterium? More than you might think. In this Lab, you'll puzzle out the evolutionary relationships linking together a spectacular array of species. Explore the tree of life and get a front row seat to what some have called the greatest show on Earth.

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China's spectacular feathered fossils have finally answered the century-old question about the ancestors of today's birds

Smithsonian Magazine |

In a pine forest in rural northeastern China, a rugged shale slope is packed with the remains of extinct creatures from 125 million years ago, when this part of Liaoning province was covered with freshwater lakes. Volcanic eruptions regularly convulsed the area at the time, entombing untold millions of reptiles, fish, snails and insects in ash. I step gingerly among the myriad fossils, pick up a shale slab not much larger than my hand and smack its edge with a rock hammer. A seam splits a russet-colored fish in half, producing mirror impressions of delicate fins and bones as thin as human hairs.

One of China's star paleontologists, Zhou Zhonghe, smiles. "Amazing place, isn't it?" he says.

It was in 1995 that Zhou and colleagues announced the discovery of a fossil from this prehistoric disaster zone that heralded a new age of paleontology. The fossil was a primitive bird the size of a crow that may have been asphyxiated by volcanic fumes as it wheeled above the lakes all those millions of years ago. They named the new species Confuciusornis, after the Chinese philosopher.

Until then, only a handful of prehistoric bird fossils had been unearthed anywhere in the world. That's partly because birds, then as now, were far less common than fish and invertebrates, and partly because birds more readily evaded mudslides, tar pits, volcanic eruptions and other geological phenomena that captured animals and preserved traces of them for the ages. Scientists have located only ten intact fossilized skeletons of the earliest known bird, Archaeopteryx, which lived at the end of the Jurassic period, about 145 million years ago.

Zhou, who works at the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) of the Chinese Academy of Sciences in Beijing, believed that the extraordinary bone beds in Liaoning might fill in some of the many blanks in the fossil record of the earliest birds. He couldn't have been more prophetic. In the past 15 years, thousands of exquisitely preserved fossil birds have emerged from the ancient lakebed, called the Yixian Formation. The region has also yielded stunning dinosaur specimens, the likes of which had never been seen before. As a result, China has been the key to solving one of the biggest questions in dinosaur science in the past 150 years: the real relationship between birds and dinosaurs.

The idea that birds-the most diverse group of land vertebrates, with nearly 10,000 living species-descended directly from dinosaurs isn't new. It was raised by the English biologist Thomas Henry Huxley in his 1870 treatise, Further Evidence of the Affinity between the Dinosaurian Reptiles and Birds. Huxley, a renowned anatomist perhaps best remembered for his ardent defense of Charles Darwin's theory of evolution, saw little difference between the bone structure of Compsognathus, a dinosaur no bigger than a turkey, and Archaeopteryx, which was discovered in Germany and described in 1861. When Huxley looked at ostriches and other modern birds, he saw smallish dinosaurs. If a baby chicken's leg bones were enlarged and fossilized, he noted, "there would be nothing in their characters to prevent us from referring them to the Dinosauria."

Still, over the decades researchers who doubted the dinosaur-bird link also made good anatomical arguments. They said dinosaurs lack a number of features that are distinctly avian, including wishbones, or fused clavicles; bones riddled with air pockets; flexible wrist joints; and three-toed feet. Moreover, the posited link seemed contrary to what everyone thought they knew: that birds are small, intelligent, speedy, warmblooded sprites, whereas dinosaurs-from the Greek for "fearfully great lizard"-were coldblooded, dull, plodding, reptile-like creatures.

In the late 1960s, a fossilized dinosaur skeleton from Montana began to undermine that assumption. Deinonychus, or "terrible claw" after the sickle-shaped talon on each hind foot, stood about 11 feet from head to tail and was a lithe predator. Moreover, its bone structure was similar to that of Archaeopteryx. Soon scientists were gathering other intriguing physical evidence, finding that fused clavicles were common in dinosaurs after all. Deinonychus and Velociraptor bones had air pockets and flexible wrist joints. Dinosaur traits were looking more birdlike all the time. "All those things were yanked out of the definition of being a bird," says paleontologist Matthew Carrano of the Smithsonian National Museum of Natural History.

But there was one important feature that had not been found in dinosaurs, and few experts would feel entirely comfortable asserting that chickadees and triceratops were kin until they had evidence for this missing anatomical link: feathers.

A poor Chinese farmer, Li Yingfang, made one of the greatest fossil finds of all time, in August 1996 in Sihetun village, an hour's drive from the site where I'd prospected for fossil fish. "I was digging holes for planting trees," recalls Li, who now has a full-time job at a dinosaur museum built at that very site. From a hole he unearthed a two-foot-long shale slab. An experienced fossil hunter, Li split the slab and beheld a creature unlike any he had seen. The skeleton had a birdlike skull, a long tail and impressions of what appeared to be feather-like structures.

Because of the feathers, Ji Qiang, then the director of the National Geological Museum, which bought one of Li's slabs, assumed it was a new species of primitive bird. But other Chinese paleontologists were convinced it was a dinosaur.

On a visit to Beijing that October, Philip Currie, a paleontologist now at the University of Alberta, saw the specimen and realized it would turn paleontology on its head. The next month, Currie, a longtime China hand, showed a photograph of it to colleagues at the annual meeting of the Society of Vertebrate Paleontology. The picture stole the show. "It was such an amazing fossil," recalls paleontologist Hans-Dieter Sues of the National Museum of Natural History. "Sensational." Western paleontologists soon made a pilgrimage to Beijing to see the fossil. "They came back dazed," Sues says.

Despite the feathers, the skeleton left no doubt that the new species, named Sinosauropteryx, meaning "Chinese lizard wing," was a dinosaur. It lived around 125 million years ago, based on the dating of radioactive elements in the sediments that encased the fossil. Its integumentary filaments-long, thin structures protruding from its scaly skin-convinced most paleontologists that the animal was the first feathered dinosaur ever unearthed. A dozen dinosaurs with filaments or feathers have since been discovered at that site.

By analyzing specimens from China, paleontologists have filled in gaps in the fossil record and traced the evolutionary relationships among various dinosaurs. The fossils finally have confirmed, to all but a few skeptics, that birds descended from dinosaurs and are the living representatives of a dinosaur lineage called the Maniraptorans.

Most dinosaurs were not part of the lineage that gave rise to birds; they occupied other branches of the dinosaur family tree. Sinosauropteryx, in fact, was what paleontologists call a non-avian dinosaur, even though it had feathers. This insight has prompted paleontologists to revise their view of other non-avian dinosaurs, such as the notorious meat eater Velociraptor and even some members of the tyrannosaur group. They, too, were probably adorned with feathers.

The abundance of feathered fossils has allowed paleontologists to examine a fundamental question: Why did feathers evolve? Today, it's clear that feathers perform many functions: they help birds retain body heat, repel water and attract a mate. And of course they aid flight-but not always, as ostriches and penguins, which have feathers but do not fly, demonstrate. Many feathered dinosaurs did not have wings or were too heavy, relative to the length of their feathered limbs, to fly.

Deciphering how feathers morphed over the ages from spindly fibers to delicate instruments of flight would shed light on the transition of dinosaurs to birds, and how natural selection forged this complex trait. Few scientists know ancient feathers more intimately than IVPP's Xu Xing. He has discovered 40 dinosaur species-more than any other living scientist-from all over China. His office at IVPP, across the street from the Beijing Zoo, is cluttered with fossils and casts.

Xu envisions feather evolution as an incremental process. Feathers in their most primitive form were single filaments, resembling quills, that jutted from reptilian skin. These simple structures go way back; even pterodactyls had filaments of sorts. Xu suggests that feather evolution may have gotten started in a common ancestor of pterodactyls and dinosaurs-nearly 240 million years ago, or some 95 million years before Archaeopteryx.

After the emergence of single filaments came multiple filaments joined at the base. Next to appear in the fossil record were paired barbs shooting off a central shaft. Eventually, dense rows of interlocking barbs formed a flat surface: the basic blueprint of the so-called pennaceous feathers of modern birds. All these feather types have been found in fossil impressions of theropods, the dinosaur suborder that includes Tyrannosaurus rex as well as birds and other Maniraptorans.

Filaments are found elsewhere in the dinosaur family tree as well, in species far removed from theropods, such as Psittacosaurus, a parrot-faced herbivore that arose around 130 million years ago. It had sparse single filaments along its tail. It's not clear why filaments appear in some dinosaur lineages but not in others. "One possibility is that feather-like structures evolved very early in dinosaur history," says Xu, and some groups maintained the structures, while other groups lost them. "But finally in Maniraptorans, feathers stabilized and evolved into modern feathers," he says. Or filaments may have evolved independently at different times. As Sues points out, "It seems that, genetically, it's not a great trick to make a scale into a filament."

Originally, single filaments may well have been for display, the dinosaur equivalent of a peacock's iridescent plumage. Vivid evidence for that theory appeared when scientists unveiled the true colors of 125-million-year-old feathers. Bird feathers and reptile scales contain melanosomes-tiny sacs holding varieties of the pigment melanin. Many paleontologists suspected that dinosaur feathers also contained melanosomes. In Mike Benton's laboratory at the University of Bristol, IVPP's Zhang Fucheng spent more than a year searching for melanosomes in photographs of bird and dinosaur fossils taken with an electron microscope. Zhang's diligence paid off in 2009 when he pinpointed melanosomes in Confuciusornis that contained eumelanin, which gives feathers a gray or black tinge, and pheomelanin, which gives them a chestnut to reddish-brown color. The animal's feathers had patches of white, black and orange-brown coloring.

Sinosauropteryx was even more stunning. Zhang found that the filaments running down its back and tail must have made the dinosaur look like an orange-and-white-striped barber pole. Such a vibrant pattern suggests that "feathers first arose as agents for color display," Benton says.

Early feathers could have served other purposes. Hollow filaments may have dissipated heat, much as the frills of some modern lizards do today. Other paleontologists speculate feathers first evolved to retain heat. A telling example comes from fossils of Oviraptor-a theropod unearthed in Mongolia that lived around 75 million years ago-squatting over egg-filled nests. Oviraptors tucked their legs into the center of the clutch and hugged the periphery with their long forelimbs-a posture bearing an uncanny resemblance to brooding birds keeping their eggs warm. Dinosaurs related to Oviraptor were covered with pennaceous feathers, suggesting that Oviraptor was as well. "Sitting on a nest like that only made sense if it had feathers" to gently insulate its young, says Sues.

Feathers did, of course, eventually become an instrument of flight. Some paleontologists envision a scenario in which dinosaurs used feathers to help them occupy trees for the first time. "Because dinosaurs had hinged ankles, they could not rotate their feet and they couldn't climb well. Maybe feathers helped them scramble up tree trunks," Carrano says. Baby birds of primarily ground-dwelling species like turkeys use their wings in this way. Feathers may have become increasingly aerodynamic over millions of years, eventually allowing dinosaurs to glide from tree to tree. Individuals able to perform such a feat might have been able to reach new food sources or better escape predators-and pass the trait on to subsequent generations.

One of the most beguiling specimens to emerge from Liaoning's shale beds is Microraptor, which Xu discovered in 2003. The bantamweight beast was a foot or two long and tipped the scales at a mere two pounds. Microraptor, from the Dromaeosaur family, was not an ancestor of birds, but it was also unlike any previously discovered feathered dinosaur. Xu calls it a "four-winged" dinosaur because it had long, pennaceous feathers on its arms and legs. Because of its fused breastbone and asymmetrical feathers, says Xu, Microraptor surely could glide from tree to tree, and it may even have been better at flying under its own power than Archaeopteryx was.

Last year, Xu discovered another species of four-winged dinosaur, also at Liaoning. Besides showing that four-winged flight was not a fluke, the new species, Anchiornis huxleyi, named in honor of Thomas Henry Huxley, is the earliest known feathered dinosaur. It came from Jurassic lakebed deposits 155 million to 160 million years old. The find eliminated the final objection to the evolutionary link between birds and dinosaurs. For years, skeptics had raised the so-called temporal paradox: there were no feathered dinosaurs older than Archaeopteryx, so birds could not have arisen from dinosaurs. Now that argument was blown away: Anchiornis is millions of years older than Archaeopteryx.

Four-winged dinosaurs were ultimately a dead branch on the tree of life; they disappear from the fossil record around 80 million years ago. Their demise left only one dinosaur lineage capable of flight: birds.

Just when did dinosaurs evolve into birds? Hard to say. "Deep in evolutionary history, it is extremely difficult to draw the line between birds and dinosaurs," says Xu. Aside from minor differences in the shape of neck vertebrae and the relative length of the arms, early birds and their Maniraptoran kin, such as Velociraptor, look very much alike.

"If Archaeopteryx were discovered today, I don't think you would call it a bird. You would call it a feathered dinosaur," says Carrano. It's still called the first bird, but more for historic reasons than because it is the oldest or best embodiment of birdlike traits.

On the other hand, Confuciusornis, which possessed the first beak and earliest pygostyle, or fused tail vertebrae that supported feathers, truly looks like a bird. "It passes the sniff test," Carrano says.

Since the last of the non-avian dinosaurs died out 65 million years ago during the mass extinction that closed the curtain on the Cretaceous period, birds have evolved other characteristics that set them apart from dinosaurs. Modern birds have higher metabolisms than even the most agile Velociraptor ever had. Teeth disappeared at some point in birds' evolutionary history. Birds' tails got shorter, their flying skills got better and their brains got bigger than those of dinosaurs. And modern birds, unlike their Maniraptoran ancestors, have a big toe that juts away from the other toes, which allows birds to perch. "You gradually go from the long arms and huge hands of non-avian Maniraptorans to something that looks like the chicken wing you get at KFC," says Sues. Given the extent of these avian adaptations, it's no wonder the evolutionary link between dinosaurs and birds as we know them remained hidden until paleontologists started analyzing the rich fossil record from China.

Chaoyang is a drab Chinese city with dusty streets; in its darker corners it's reminiscent of gritty 19th-century American coal-mining towns. But to fossil collectors, Chaoyang is a paradise, only a one-hour drive from some of the Yixian Formation's most productive beds.

One street is lined with shops selling yuhuashi, or fish fossils. Framed fossils embedded in shale, often in mirror-image pairs, can be had for a dollar or two. A popular item is a mosaic in which a few dozen small slabs form a map of China; fossil fish appear to swim toward the capital, Beijing (and no map is complete without a fish representing Taiwan). Merchants sell fossilized insects, crustaceans and plants. Occasionally, despite laws that forbid trade in fossils of scientific value, less scrupulous dealers have been known to sell dinosaur fossils. The most important specimens, Zhou says, "are not discovered by scientists at the city's fossil shops, but at the homes of the dealers or farmers who dug them."

In addition to Sinosauropteryx, several other revelatory specimens came to light through amateurs rather than at scientific excavations. The challenge for Zhou and his colleagues is to find hot specimens before they disappear into private collections. Thus Zhou and his colleague Zhang Jiangyong, a specialist on ancient fish at IVPP, have come to Liaoning province to check out any fossils that dealers friendly to their cause have gotten their hands on of late.

Most of the stock in the fossil shops comes from farmers who hack away at fossil beds when they aren't tending their fields. A tiny well-preserved fish specimen can yield its finder the equivalent of 25 cents, enough for a hot meal. A feathered dinosaur can earn several thousand dollars, a year's income or more. Destructive as it is to the fossil beds, this paleo economy has helped rewrite prehistory.

Zhou picks up a slab and peers at it through his wire-rimmed glasses. "Chairman, come here and look," Zhou says to Zhang (who earned his playful nickname as chairman of IVPP's employees union). Zhang examines the specimen and adds it to a pile that will be hauled back to Beijing for study-and, if they are lucky, reveal another hidden branch of the tree of life.

Richard Stone has written about a Stonehenge burial, a rare antelope and mysterious Tibetan towers for Smithsonian.

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Smithsonian Magazine | In a pine forest in rural northeastern China, a rugged shale slope is packed with the remains of extinct creatures from 125 million years ago, when this part of Liaoning province was covered with freshwater lakes. Volcanic eruptions regularly convulsed the area at the time, entombing untold millions of reptiles, fish, snails and insects in ash.

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We appreciate your feedback and any suggestions on additional resources. Please complete the google form.

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MS-PS4-1, MS-PS4-2, MS-PS4-3

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How Can We Sense So Many Different Sounds From A Distance?

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In this unit, students start by observing a perplexing phenomenon. When a sewing needle taped to a cone, is dragged over the surface of a plastic disc that is spun underneath it, voices and musical notes can be heard coming from it.

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Extreme Makover NGSS, Episode 2: Crater Lab

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MS-PS2-1 Evidence Statements June 2015.pdf

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MS-LS4-1 Evidence Statements June 2015.pdf

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Building a dinosaur from a chicken | Jack Horner

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Examines evidence to support different explanations for what killed the dinosaurs. See tabs just below title.

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Evolution: Extinction: What Killed the Dinosaurs?

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In the search for answers to what killed the dinosaurs, scientists have looked beyond fossils. Geological evidence also holds clues and has contributed to many hypotheses, working explanations of how dinosaurs may have become extinct.

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How To Find a Dinosaur | HHMI BioInteractive Video

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SNAP Sample Questions

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Genetics Performance Assessment | Science Education

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8th grade - short-term IEA based on genetics. This instructionally imbedded assessment asks a group of students to collaborate as they develop a model showing the relationship between traits, genes, and proteins.

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Tulare County Office of Education Library Portal

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Tulare County Office of Education Library Portal

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"Check it out" portal, and other reading resources.

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Uses Google Sci Journal

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Learn about the differences between analog and digital signals using Google's Science Journal app in this fun lesson plan.

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Explore: Making and hearing sounds - interactive lab

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Explore: Making and hearing sounds - interactive lab

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We communicate constantly using our voices and our ears, and we're very good at it! We can express very complex things using spoken words, variations in tone or inflection, and singing. We can hear all of those verbalizations in rich detail with our ears.

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The Day the Mesozoic Died: The Asteroid That Killed the Dinosaurs - HHMI BioInteractive Video

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Ever wonder why the dinosaurs disappeared? HHMI BioInteractive investigates the cause of the mass extinction at the end of the Cretaceous period-and the clues come from paleontology, chemistry, physics, and biology. This three-act film tells the story of the extraordinary detective work that solved one of the greatest scientific mysteries of all time.

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HHMI's BioInteractive - Click and Learn - The Making of Mass Extinctions

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Post with 0 votes and 111758 views. A Way to Remember Deep Time

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MS-PS4-3

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Learn about the differences between analog and digital signals using Google's Science Journal app in this fun lesson plan.

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Explore: Transmission and Absorption of Light

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Explore: Transmission and Absorption of Light

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MS-PS4-2

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Fun lesson where students explore light transmission, reflection and absorption with Google's Science Journal App.

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World Modeler

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scroll down for ideas by standard

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Tidal Locking | Why Do We Only See One Side of the Moon?

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Our tasks are intended to be used to support teaching and learning in classrooms that are enacting NGSS-aligned instruction. Currently, we have made available through our portal a comprehensive set of assessment tasks and rubrics for middle school physical science and life science.

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Sound Scrubber IEA (MS Physical Science).zip

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SNAP sample questions

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Formative Assessment Probes
Page Keeley 2017-08-05 01:09:36
Uncovering Preservice Teachers' Ideas About Magnetism and Formative Assessment Magnets are common, everyday objects people can find in their homes. They attach notes and pictures to refrigerators, close cabinet and refrigerator doors, hold cans for electric can openers, weight shower curtains, connect power cords to Apple laptop computers, and make up components of some games. Most adults have used magnets sometime over the course of their K-12 science education. For all these multiple experiences with magnetic interactions, one may assume adults understand basic concepts about magnets and magnetism. A study of 245 preservice elementary teachers by Atwood and Christopher (2006) revealed a limited understanding of magnetism concepts. Preservice teachers were asked five questions focused on properties and phenomena related to magnetism that could be directly investigated in the elementary classroom. The poor results indicated that magnets and magnetic behavior should be included in science methods courses that prepare elementary teachers, especially since magnetism is a common elementary curricular unit and is included in most elementary science standards. The formative assessment probes in NSTA's Uncovering Student Ideas in Science series were developed to surface ideas children bring to the classroom that are often inconsistent with scientific views of concepts and phenomena. These strongly held ideas make sense to the learner and may resurface in adulthood, even after instructional opportunities have been provided in the K-6 curriculum. Therefore, it is just as important to use formative assessment probes with preservice teachers to elicit their preconceptions as it is to use them with the students they will be teaching. The formative assessment probe "Can You Pick It up With a Magnet?" (Figure 1; Keeley and Harrington 2014) is designed to find out what types of materials students think interact with magnets. A commonly held idea elementary students have is that all metals interact with magnets. Students fail to recognize that only materials containing iron interact with magnets. Could preservice teachers have this idea as well? Recently I had the opportunity to introduce formative assessment probes to an elementary science methods class. I used the Can You Pick It Up With a Magnet? probe to demonstrate the importance of eliciting students' initial ideas before launching into an activity. The preservice teachers made predictions and discussed reasons for their predictions. Their ideas mirrored the research findings, predicting that the metals on the list, especially the silver-colored ones, would interact with magnets. A few of the students included the pencil lead and mirror. Their reasoning that all metals are magnetic materials was supported by examples of everyday interactions between metals and magnets that they had observed. After discussion, the preservice teachers were given magnets to test whether the objects made from the materials on the list interacted with a magnet. They were surprised to find out that only the objects containing iron or magnetic materials interacted with magnets. Aluminum foil created much dissonance when it failed to be attracted to a magnet, as the students were sure the shiny, metal foil would readily stick to a magnet. We debriefed the activity, developing the idea of ferromagnetic materials like iron interacting with magnets but also materials such as cobalt and nickel. However, the most important takeaway for these preservice teachers was not the content. It was that good teaching starts with uncovering what students already know or think they know about a scientific concept, object, or phenomenon. This process of "uncovering" activates students' thinking and creates a desire to investigate. By making and justifying their initial predictions first, the process of testing their ideas and seeing if their observations matched their prediction was a much more powerful way to learn than merely launching into an activity to find out which types of materials interacted with magnets. The formative assessment probe was the tool to prime students' thinking and pique their interest in learning the content. It also showed them that both students and teachers should not assume that they already know something, even when it may have been taught previously. While misconceptions may be considered obstacles to learning, they can also provide the raw material to stimulate learning. These teachers realized that doing a probe themselves, along with examining the supporting background notes, could help them learn the science they teach in the elementary grades. Following our debrief of the probe, the preservice teachers experienced and examined several other probes related to magnetism, which surfaced ideas they had that may have affected how they taught their science lessons. It helped them see the importance of eliciting their own initial thinking before launching into activities and reinforced the value of using students' ideas to plan effective instruction. Page Keeley (pagekeeley@gmail.com) is a science education consultant and the author of the Uncovering Student Ideas in Science series (http://uncoveringstudentideas.org). References Atwood, R., and J. Christopher. 2006. Preservice elementary teachers' understanding of standards-based magnetism concepts. Paper presented at the MSP Evaluation Summit. Minneapolis, MN. Keeley, P., and R. Harrington. 2014. Uncovering student ideas in physical science: 39 new electricity and magnetism formative assessment probes. Arlington, VA: NSTA Press.

Published by NSTA. View All Articles.

This page can be found at http://digital.nsta.org/article/Formative+Assessment+Probes/2849747/429899/article.html.

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Page Keeley 2017-08-05 01:09:36 Uncovering Preservice Teachers' Ideas About Magnetism and Formative Assessment Magnets are common, everyday objects people can find in their homes. They attach notes and pictures to refrigerators, close cabinet and refrigerator doors, hold cans for electric can openers, weight shower curtains, connect power cords to Apple laptop computers, and make up components of some games.

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Introducing the Understanding Science Flowchart to middle school students lesson

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Overview: Students begin with a simple "warm up" activity that introduces them to the process of science. The class discusses whether or not they were "doing" science. Students then read a story about the geoscientist, Walter Alvarez, and identify phrases within the story that indicate that Alvarez was doing science.

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Your Bottle Racer may be simple, but it shares an important similarity with larger, more complicated vehicles: It converts stored potential energy into kinetic energy, the energy of motion.

As you wind up the rubber band with the straw, you do mechanical work, applying a force over a distance. The mechanical work done in winding up the rubber band is stored in the rubber band as spring potential energy. When you let the bottle go, the potential energy is released as kinetic energy, the energy of motion.

Here, energy gets stored in a stretched spring, but energy can be stored in plenty of other ways. Lifting an object against the force of gravity stores gravitational potential energy. To release this stored energy, all you have to do is let go and watch the object fall. Conventional cars get their "go" from chemical potential energy -energy stored in chemical bonds-in the form of gasoline, lithium-ion batteries, or even hydrogen.

Friction is an important and necessary part of getting this or any other car to move. For a car to move forward, it must push backward on the road (or floor) beneath it-so says Newton's Third Law of Motion: For every action, there is an equal and opposite reaction. The frictional force between the tires (or bottle) and the road (or floor) is the action, and the reaction is the road pushing forward on the tires. Just as you couldn't take a step forward on perfectly frictionless ice, your car can't move forward without friction.

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Your Bottle Racer may be simple, but it shares an important similarity with larger, more complicated vehicles: It converts stored potential energy into kinetic energy, the energy of motion. As you wind up the rubber band with the straw, you do mechanical work, applying a force over a distance.

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MS-PS3-1 PS3.A Energy Skate Park Online Simulation

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Java Player Required

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Explore the forces at work when you try to push a filing cabinet. Create an applied force and see the resulting friction force and total force acting on the cabinet. Charts show the forces, position, velocity, and acceleration vs. time. View a Free Body Diagram of all the forces (including gravitational and normal forces).

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Explore the forces at work when pulling against a cart, and pushing a refrigerator, crate, or person. Create an applied force and see how it makes objects move. Change friction and see how it affects the motion of objects.