# data[].attributes.body
1. A  possible explanation for a set of observations or possible answer to a scientific question
2. monomers
3. the power house of a cell
4. a substance that is dissolved in a solution
5. yes
6. process of copying DNA
7. a dominant trait
8. Charles Darwin
9. carries water upward from the roots throughout the plant
10. plants and animals
11. the entering of an population into an area
12. hypertension
13. site of protein synthesis
14. cytoplasm
15. adenosine triphosphate
16. plant cell has a cell wall and chloroplast
17. network of feeding interactions
18.  capillary
19. population stops growing or decreases a little
20. it is the diffusion of water through a selectively permeable membrane

# data[].attributes.body
1.What is a hypothesis?
2. What are polymers composed of?
3.What is the mitochondria?
4. What is the definition of solute?
5. Is the cell cycle important?
6.What is DNA replication?
7. What is the opposite of a recessive trait?
8. Who was the first to discovery evolution?
9. What does the xylem in a plant do?
10.What does an omnivore eat
11. Define immigration
12. What is high blood pressure called?
13.What is the ribosome
14. What fluid surrounds the organelles inside of a cells?
15. What is ATP short for
16. What is the difference between a plant and animal cell?
17. What is a food web
18. What is the smallest blood vessel?
19. What happens when a population reaches its carrying capacity?
20. Define osmosis

# data[].attributes.body
1. a
2. c
3.b
4.b
5.b
6.c
7.a
8.a
9.c
10.c
11.b
12.b

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FREE resources for teaching your students about human body systems

Scroll down, place your cursor on the body system you want to explore, and click. Each body system includes 3 FREE* teaching resources: an introductory infographic, an activity or article, and a graphic organizer.

* ©Carolina Biological Supply Company
Carolina Biological Supply Company grants teachers permission to photocopy or reproduce by other means these resources in quantities sufficient for the students in his/her classroom. Also for the purposes of classroom use only, teachers may make an electronic file or overhead transparency of any or all pages in these resources.

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Scroll down, place your cursor on the body system you want to explore, and click. Each body system includes 3 FREE* teaching resources: an introductory infographic, an activity or article, and a graphic organizer. * ©Carolina Biological Supply Company Carolina Biological Supply Company grants teachers permission to photocopy or reproduce by other means these resources in quantities sufficient for the students in his/her classroom.

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What an ecological population is. How scientists define and measure population size, density, and distribution in space.

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Printer Friendly

Energy and matter characterize both physical and biological systems. These systems are defined both by the types of energy and matter they contain and by how that matter and energy move through and between systems. In natural systems, both energy and matter are conserved within a system. This means that energy and matter can change forms but cannot be created or destroyed. Energy and matter are often cycled within a system, and different forms of matter and energy are able to interact. The surrounding environment must be considered when studying a system's energy and matter to examine flow into and out of the system. Scientists seek to study the flow and interactions of matter and energy, while engineers often seek to minimize inputs and maximize outputs of matter and energy relative to a given system.

Ocean and aquatic scientists and engineers study a variety of types of matter and energy. For example, biogeochemists describe how matter is cycled and energy is transformed at large and small scales. Biogeochemists might examine cycles of elements and compounds such as water, carbon, and mercury (Fig. 2.17). Some ecologists examine the variation in stages of decomposition of whale falls. Ocean engineers are developing ways to transform wind and wave energy at sea into usable electricity for people in coastal regions and beyond.

According to the framework, the crosscutting concept of energy and matter can be used to develop understanding across physical, life, and Earth science disciplines. Due to the abstract and complex nature of energy, the NGSS do not introduce energy concepts until grade three. At this level, students can understand the flow of energy into and out of systems. Matter can also be an abstract concept, especially at the molecular level. For this reason, the idea of atoms is not introduced in the NGSS until middle school. However, all students can observe and describe the transfer of matter at the macroscopic level. In middle and high school, the concept of the conversion of forms of matter and energy can be developed. Appropriate investigations can be used to address common misconceptions about matter and energy.

Exploring Our Fluid Earth, a product of the Curriculum Research & Development Group (CRDG), College of Education. University of Hawaii, 2011. This document may be freely reproduced and distributed for non-profit educational purposes.

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Energy and Matter: Flows, Cycles and Conservation

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Printer Friendly Energy and matter characterize both physical and biological systems. These systems are defined both by the types of energy and matter they contain and by how that matter and energy move through and between systems. In natural systems, both energy and matter are conserved within a system.

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Plants are an incredibly important kingdom of organisms. They are multicellular organisms with the amazing ability to make their own food from carbon dioxide in the atmosphere. They provide the foundation of many food webs and animal life would not exist if plants were not around. The study of plants is known as botany and in this introduction to plants we look at key topics such as the process of photosynthesis, different types of plants and the different parts of a plant such as roots, stems and leaves.

By using the sun's energy to fix carbon dioxide, plants are able to produce sugars through a process known as photosynthesis. The sugars produced through photosynthesis provide plants with the energy to survive, grow and reproduce. As plants grow they become a food source for animals and other organisms.

There are over 400,000 species of plants currently on Earth and the majority of them produce flowers and fruit for reproduction. Plants that produce flowers belong to a group called angiosperms.

Other woody plants include a group known as the gymnosperms. This group includes pine trees and their relatives plus other non-flowering trees. Less advanced plants include ferns, lycophytes and mosses.

Plants made the move from water to land around 500 million years ago. Living on land is significantly different to living on water and plants have had to make serious changes to their body plans in order survive on land.

Land plants separated their body plans into roots, stems and leaves. Roots absorb water and nutrients from soil, stems transfer materials between roots and leaves, and leaves produce sugars that provide the plant with energy to survive.

Photosynthesis

Photosynthesis is a key topic for an introduction to plant biology. It is a process that occurs in plant cells that uses the sun's energy to produce sugars from carbon dioxide and water. The process is simply a series of chemical reactions, probably the most important chemical reactions of Earth.

The green color of plants is caused by a molecule called chlorophyll . Chlorophyll has the ability to absorb light energy from the sun. The energy that is absorbed is used to force reactions with water and carbon dioxide. The result of these reactions is the production sugars and oxygen gas.

The overall reaction looks like this:
energy + water + carbon dioxide → sugar + oxygen

Photosynthesis takes carbon dioxide from the atmosphere, converts it into sugar and releases oxygen back into the atmosphere. Over time photosynthesis changed the atmosphere of the Earth by increasing the amount of oxygen in the air.

Vascular vs. non-vascular

A critical step in the evolution of current plant species was the evolution of vascular tissue. Like humans have vascular tissue that transports blood through our bodies, the majority of species of plants have vascular tissue that transports water and nutrients around their bodies.

Before plants evolved vascular tissue, water was only able to enter into a plant by diffusing through the plant's cells. This meant plants were unable to grow very large because diffusion is not efficient enough to support large plants. Once plants evolved vascular tissue, they were able to grow much larger and which allowed the evolution of the giant trees that now grace the Earth's lands.

There are still many species on non-vascular plants but the vast majority of plant species contain vascular tissue. Non-vascular plants include organisms such as mosses and liverworts. Some biologists also consider the green algae to be non-vascular plants. Because non-vascular plants rely on diffusion to absorb water they are typically found in moist environments.

Vascular plants make up over 90% of all plant species that are currently found on Earth. More primitive vascular plants include lycophytes and ferns. These two groups reproduce with spores rather than seeds and are unable to produce wood.

Gymnosperms and angiosperms are the two most recently evolved groups of vascular plants. They can both produce wood and reproduce with seeds rather than spores.

Plant body plan

Plants have a relatively simple body plan. A plant can be split into two sections: the underground system known as roots and the above ground system referred to as shoots. The shoots typically include stems, branches and leaves.

The evolution of roots was key to the success of plants on land. Roots grow underground in search for water and nutrients in the soil. Often almost half of a plant's mass is hidden underground in the root system.

Roots also help to anchor a plant to the ground so it doesn't get blown away in the wind or in a flood. They can also be used to store excess food to be used at a later date.

Stems and branches connect leaves and roots to each other. They are the 'highways' that water, nutrients, and sugars travel through to nourish the various parts of a plant.

Branches and stems influence the height and size of a plant which in turn affects how much light it will receive from the sun. A stem and branch can be green and fleshy but in many plants, they are brown, woody and covered in bark.

Leaves are the main place where photosynthesis occurs. The leaves of the plant have the responsibility of producing enough energy to feed the entire plant. Leaves are optimized for this challenge.

A typical leaf is full of a green molecule called chlorophyll which is the magic ingredient in photosynthesis. Chlorophyll is able to use energy from the sun to kick start the process of photosynthesis. Leaves are also usually flat and have large surface areas to capture as much light from the sun as possible.

Angiosperms

An angiosperm is any plant that produces flowers, fruit, and seeds. They are the most advanced, diverse and abundant group of plants. Angiosperms include the majority of the plants that most people are familiar with such as grasses, orchids, roses, lavender, magnolias, plus the plants that produce the fruits, vegetables, grains and nuts that we regularly eat.

Flowers and fruit evolved as a part of a plant's reproduction. Flowers produce pollen and an ovary. Pollen from one flower is delivered to the ovary of another flower - this is known as pollination. A sperm cell found in a pollen grain fertilizes an egg located in an ovary. Once the egg is fertilized, it develops into a seed and the ovary develops into a fruit.

Angiosperms have a close relationship with animals, in particular insects and birds. The pollination of flowers is most commonly assisted by animals. Flowers provide animals with nutritious foods such as nectar and pollen.

As animals move between flowers feeding on nectar and pollen, they transfer pollen between flowers. The newly delivered pollen then has the ability to fertilize the egg of the new flower.

Many angiosperms and animals have evolved alongside each other and their survival depends on one another. If the angiosperm goes extinct, the animal loses its food source. If the animal goes extinct, the plant loses it pollinator and cannot reproduce.

Gymnosperms

Gymnosperms are the closest relatives of angiosperms. They are a group of woody plants that produce seeds but no flowers or fruit. The seeds of gymnosperms are usually found in cones rather than inside fruit.

The world's largest, tallest, oldest and widest organisms are all gymnosperms. They are incredible plants and some species are known to survive for over 2000 years.

There are four different groups of gymnosperms. These include the gingko, gnetophyta, cycads and conifers. Conifers contain the majority of species and include the well-known pine trees.

Ferns and lycophytes

Ferns and lycophytes are non-woody plants and also don't produce seeds, flowers or fruit. Instead, ferns and lycophytes reproduce using tiny structures called spores.

These two groups were once the most common plants of Earth but they have since been outgrown by gymnosperms and angiosperms. Still, around 12,000 species of ferns and 1,200 species of lycophytes remain on Earth.

The main difference between ferns and lycophytes is in the vascular tissue of their leaves. Ferns have fronds with multiple veins whereas the leaves of lycophytes are very simple and only have one vein.

Non-vascular plants

Besides lacking tissue, non-vascular plants also lack wood, roots and flowers. This group of often ignored plants includes mosses, hornworts, liverworts and (depending on who you're talking to) some algae. Compared to vascular plants, non-vascular plants are small and they struggle to grow taller than a few centimeters.

Mosses are the most common and best known of the non-vascular plants. They include over 14,000 species that are found all around the world.

Liverworts and hornworts are two groups of underappreciated plants. They are flattened plants that are typically only a few millimeters tall but grow sprawling across moist surfaces and are commonly mistaken for mosses and algae.

Video by Frank Gregorio. To see more brilliant videos like this one, check out Greg's vimeo channel

For a deeper look at the biology of plants check out the plant section of our website:
Plants - Basic Biology

Last edited: 16 December 2016

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Plants are an incredibly important kingdom of organisms. They are multicellular organisms with the amazing ability to make their own food from carbon dioxide in the atmosphere. They provide the foundation of many food webs and animal life would not exist if plants were not around.

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Evolution | Definition, History, Types, & Examples

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Evolution, theory in biology postulating that the various types of living things on Earth have their origin in other preexisting types and that the distinguishable differences are due to modifications in successive generations. The theory of evolution is one of the fundamental keystones of modern biological theory.

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Genetics biotechnology study guide Flashcards | Quizlet

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Start studying Genetics biotechnology study guide. Learn vocabulary, terms, and more with flashcards, games, and other study tools.

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RNA is an intermediary between DNA and protein :: DNA from the Beginning

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The Central Dogma is the flow of genetic information from DNA, to RNA, to protein.

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mitosis, a process of cell duplication, or reproduction, during which one cell gives rise to two genetically identical daughter cells. Strictly applied, the term mitosis is used to describe the duplication and distribution of chromosomes, the structures that carry the genetic information.

A brief treatment of mitosis follows. For a full treatment, see growth: In cells; cell: Mitosis and cytokinesis.

Prior to the onset of mitosis, the chromosomes have replicated and the proteins that will form the mitotic spindle have been synthesized. Mitosis begins at prophase with the thickening and coiling of the chromosomes. The nucleolus, a rounded structure, shrinks and disappears. The end of prophase is marked by the beginning of the organization of a group of fibres to form a spindle and the disintegration of the nuclear membrane.

The chromosomes, each of which is a double structure consisting of duplicate chromatids, line up along the midline of the cell at metaphase. In anaphase each chromatid pair separates into two identical chromosomes that are pulled to opposite ends of the cell by the spindle fibres. During telophase, the chromosomes begin to decondense, the spindle breaks down, and the nuclear membranes and nucleoli re-form. The cytoplasm of the mother cell divides to form two daughter cells, each containing the same number and kind of chromosomes as the mother cell. The stage, or phase, after the completion of mitosis is called interphase.

Mitosis is absolutely essential to life because it provides new cells for growth and for replacement of worn-out cells. Mitosis may take minutes or hours, depending upon the kind of cells and species of organisms. It is influenced by time of day, temperature, and chemicals.

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Mitosis | Definition, Stages, Diagram, & Facts

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Mitosis, a process of cell duplication, or reproduction, during which one cell gives rise to two genetically identical daughter cells. Strictly applied, the term is used to describe the duplication and distribution of chromosomes, the structures that carry the genetic information.

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Start studying Cell Transport and Transport Properties. Learn vocabulary, terms, and more with flashcards, games, and other study tools.

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BACKGROUND KNOWLEDGE

Introduction to the cell

Both living and non-living things are composed of molecules made from chemical elements such as Carbon, Hydrogen, Oxygen, and Nitrogen. The organization of these molecules into cells is one feature that distinguishes living things from all other matter.

The cell is the smallest unit of matter that can carry on all the processes of life .

1. Every living thing, from the tiniest bacterium to the largest whale, is made of one/more cells

2. Before the C17th, no one knew that cells existed, since they are too small to be seen with the naked eye. The invention of the microscope enabled Robert Hooke, (1665) and Anton van Leuwenhoek (1675) to see and draw the first 'cells', a word coined by Hooke to describe the cells in a thin slice of cork, which reminded him of the rooms where monks lived.

3. The idea that all living things are made of cells was put forward in about 1840 and in 1855 came 'Cell Theory' - i.e. 'cells only come from other cells' - contradicting the earlier theory of 'Spontaneous Generation'.

Cell Theory consists of three principles:

1. All living things are composed of one or more cells.

2. Cells are the basic units of structure and function in an organism.

3. Cells come only from the replication of existing cells.

Cell diversity

Not all cells are alike. Even cells within the same organism show enormous diversity in size, shape, and internal organization. Your body contains around 1013 to 1014 cells of around 300 different cell types, which we broadly classify into 4 groups.

1. A few types of cells are large enough to be seen by the unaided eye. The human egg (ovum) is the largest cell in the body, and can (just) be seen without the aid of a microscope.

2. Most cells are small for two main reasons:

1. The cell's nucleus can only control a certain volume of active cytoplasm.

2. Cells are limited in size by their surface area to volume ratio. A group of small cells has a relatively larger surface area than a single large cell of the same volume. This is important because the nutrients, oxygen, and other materials a cell requires must enter through it surface. As a cell grows larger at some point its surface area becomes too small to allow these materials to enter the cell quickly enough to meet the cell's need. (= Fick's Law - something you need to learn well.)

Rate of diffusion α Surface Area x Concentration
Difference Distance

Cell shape

Cells come in a variety of shapes - depending on their function

The neurones from your toes to your head are long and thin

Blood cells are rounded disks, so that they can flow smoothly

Internal organisation

1. Cells contain a variety of internal structures called organelles

2. An organelle is a cell component that performs a specific function in that cell

3. Just as the organs of a multicellular organism carry out the organism's life functions, the organelles
of a cell maintain the life of the cell

4. There are many different cells; however, there are certain features common to all cells

5. The entire cell is surrounded by a thin cell membrane
All membranes have the same thickness and basic structure

6. Organelles often have their own membranes too - once again, these membranes have a similar structure

7. The nucleus, mitochondria and chloroplasts all have double membranes, more correctly called envelopes

8. Because membranes are fluid mosaics, the molecules making them up - phospholipids and proteins - move independently. The proteins appear to 'float' in the phospholipids bilayer

9. Membranes can thus be used to transport molecules within the cell e.g. endoplasmic reticulum.

10. Proteins in the membrane can be used to transport substances across the membrane
- e.g. by facilitated diffusion or by active transport.

11. The proteins on the outside of cell membranes identify us as unique.

Prokaryotes vs. Eukaryotes

Organisms whose cells normally contain a nucleus are called Eukaryotes; those (generally smaller) organisms whose cells lack a nucleus and have no membrane-bound organelles are known as Prokaryotes.

Type of nucleus
Nuclear body
No nucleus

Real nucleus with nuclear envelope DNA circular (ccc DNA) linear molecules (chromosomes) with histone proteins

Cell division
Binary fission (simple division)

Mitosis (normal cell replication)
Meiosis (gamete production)

Parts of the eukaryotic cell

The structures that make up a Eukaryotic cell are determined by the specific functions carried out by the cell. Thus, there is no typical Eukaryotic cell. Nevertheless, Eukaryotic cells generally have three main components: A cell membrane, a nucleus, and a variety of other organelles.

The cell membrane

1. A cell cannot survive if it is totally isolated from its environment. The cell membrane is a complex barrier separating every cell from its external environment.

2. This "Selectively Permeable" membrane regulates what passes into and out of the cell.

3. The cell membrane is a fluid mosaic of proteins floating in a phospholipid bilayer.

4. The cell membrane functions like a gate, controlling which molecules can enter and leave the cell.

5. The cell membrane controls which substances pass into and out of the cell. Carrier proteins in or on the membrane are specific, only allowing a small group of very similar molecules through. For instance, α- glucose is able to enter; but β - glucose is not. Many molecules cannot cross at all. For this reason, the cell membrane is said to be selectively permeable.

6. Cell membranes are made mostly of phospholipid molecules. They have only two fatty acid 'tails' as one has been replaced by a phosphate group (making the 'head').

7. The head is charged and so polar; the tails are not charged and so are non-polar.

8. The two ends of the phospholipid molecule have different properties in water. The phosphate head is hydrophyllic and so the head will orient itself so that it is as close as possible to water molecules.

9. The fatty acid tails are hydrophobic and so will tend to orient themselves away from water.

10. So, when in water, phospholipids line up on the surface with their phosphate heads sticking into the water and fatty acid tails pointing up from the surface.

11. Cells are bathed in an aqueous environment and since the inside of a cell is also aqueous, both sides of the cell membrane are surrounded by water molecules.

12. This causes the phospholipids of the cell membrane to form two layers, known as a phospholipid bilayer. In this, the heads face the watery fluids inside and outside the cell, whilst the fatty acid tails are sandwiched inside the bilayer.

13. The cell membrane is constantly being formed and broken down in living cells.

1. Everything within the cell membrane which is not the nucleus is known as the cytoplasm.

2. Cytosol is the jelly-like mixture in which the other organelles are suspended, so cytosol + organelles = cytoplasm.

3. Organelles carry out specific functions within the cell.

4. In Eukaryotic cells, most organelles are surrounded by a membrane, but in Prokaryotic cells there are no membrane-bound organelles.

Fluid mosaic model of cell membranes

1. Membranes are fluid and are rather viscous - like vegetable oil.

2. The molecules of the cell membrane are always in motion, so the phospholipids are able to drift across the membrane, changing places with their neighbour.

3. Proteins, both in and on the membrane, form a mosaic, floating in amongst the phospholipids.

4. Because of this, scientists call the modern view of membrane structure the 'Fluid Mosaic Model'.

5. The mosaic of proteins in the cell membrane is constantly changing.

Membrane proteins

1. A variety of protein molecules are embedded in the basic phospholipid bilayer

2. Some proteins are attached to the surface of the cell membrane on both the internal and external surface. These may be hormone receptors, enzymes or cell recognition proteins (or antigens)

3. Other proteins are embedded in the phospholipid bilayer itself. These are often associated with transporting molecules from one side of the membrane to the other and are referred to as carrier proteins.

4. Some of these form channels or pores through which certain substances can pass (facilitated diffusion), whilst others bind to a substance on one side of the membrane and carry it to the other side of the membrane (active transport)

5. Proteins exposed to the cell's external environment often have carbohydrates attached to them which act as antigens (e.g. blood groups A & B - group AB has both; group O has neither).

6. Some viruses may also bind here too.

The nucleus (pl. nuclei)

1. The Nucleus is normally the largest organelle within a Eukaryotic cell. But it is NOT the 'BRAIN' of the cell!!

2. Prokaryotes have no nucleus, having a nuclear body instead. This has no membrane and a loop of DNA (and no chromatin proteins)

3. The nucleus contains the cell's chromosomes (human, 46, fruit fly 6, fern 1260) which are normally uncoiled to form a chromatinic network, which contain both linear DNA and proteins, known as histones. These proteins coil up (dehydrate) at the start of nuclear division, when the chromosomes first become visible.

4. Whilst most cells have a single nucleus some cells (macrophages, phloem companion cells) have more than one.

5. Fungi have many nuclei in their cytoplasm - they are coenocytic (= common cytoplasm throughout)

6. The nucleus is surrounded by a double membrane called the nuclear envelope.

7. The nuclear envelope has many nuclear pores through which mRNA, and proteins can pass. These dimples make it look like a golf ball.

8. Most nuclei contain at least one nucleolus (plural, nucleoli). The nucleoli are where ribosomes are synthesised. Ribosomes, you remember, translate mRNA into proteins.

9. When a nucleus prepares to divide, the nucleolus disappears.

Comparison of structures between animal and plant cells

Mitochondria

1. Mitochondria are found scattered throughout the cytosol, and are relatively large organelles (second only to the nucleus and chloroplasts)

2. Mitochondria are the sites of aerobic respiration, in which energy from organic compounds is transferred to ATP. For this reason they are sometimes referred to as the 'powerhouse' of the cell

3. ATP is the molecule that most cells use as their main energy 'currency'

4. Mitochondria are more numerous in cells that have a high energy requirement - our muscle cells contain a large number of mitochondria, as do liver, heart and sperm cells

5. Mitochondria are surrounded by two membranes, indicating that they were once free-living organisms that have become mutualistic and then a part of almost every eukaryotic cell (not RBC's and xylem vessels)

1. The smooth outer membrane serves as a boundary between the mitochondria and the cytosol.

2. The inner membrane has many long folds, known as cristae, which greatly increase the surface area of the inner membrane, providing more space for ATP synthesis to occur.

6. Mitochondria have their own DNA, and new mitochondria arise only when existing ones grow and divide. They are thus semi-autonomous organelles.

Ribosomes

1. Unlike most other organelles, ribosomes are not surrounded by a membrane

2. Ribosomes are the site of protein synthesis in a cell

3. They are the most common organelles in almost all cells

4. Some are free in the cytoplasm (Prokaryotes)
others line the membranes of rough endoplasmic reticulum (rough ER)

5. They exist in two sizes: 70S are found in all Prokaryotes, chloroplasts and mitochondria, suggesting that they have evolved from ancestral Prokaryotic organisms. They are free-floating. 80S found in all eukaryotic cells - attached to the rough ER (they are rather larger)

6. Groups of 80s ribosomes, working together, are known as a polysome.

Endoplasmic reticulum (ER)

1. The ER is a system of membranous tubules and sacs

2. The primary function of the ER is to act as an internal transport system, allowing molecules to move from one part of the cell to another

3. The quantity of ER inside a cell fluctuates, depending on the cell's activity. Cells with a lot include secretory cells and liver cells

4. The rough ER is studded with 80s ribosomes and is the site of protein synthesis. It is an extension of the outer membrane of the nuclear envelope, so allowing mRNA to be transported swiftly to the 80s ribosomes, where they are translated in protein synthesis

5. The smooth ER is where polypeptides are converted into functional proteins and where proteins are prepared for secretion. It is also the site of lipid and steroid synthesis, and is associated with the Golgi apparatus. Smooth ER has no 80s ribosomes and is also involved in the regulation of calcium levels in muscle cells, and the breakdown of toxins by liver cells

6. Both types of ER transport materials throughout the cell.

Golgi apparatus

1. The Golgi apparatus is the processing, packaging and secreting organelle of the cell, so it is much more common in glandular cells.

2. The Golgi apparatus is a system of membranes, made of flattened sac-like structures called cisternae.

3. It works closely with the smooth er, to modify proteins for export by the cell.

1. Lysosomes are small spherical organelles that enclose hydrolytic enzymes within a single membrane

2. Lysosomes are the site of protein digestion - thus allowing enzymes to be re-cycled when they are no longer required. They are also the site of food digestion in the cell, and of bacterial digestion in phagocytes

3. Lysosomes are formed from pieces of the Golgi apparatus that break off

4. Lysosomes are common in the cells of Animals, Protoctista and even Fungi, but rare in plants.

Cytoskeleton

1. Just as your body depends on your skeleton to maintain its shape and size, so a cell needs structures to maintain its shape and size

2. In animal cells, which have no cell wall, an internal framework called the cytoskeleton maintains the shape of the cell, and helps the cell to move

3. The cytoskeleton consists of two structures: a) microfilaments (contractile). They are made of actin, and are common in motile cells. b) microtubules (rigid, hollow tubes - made of tubulin).

4. Microtubules have three functions:

1. To maintain the shape of the cell

2. To serve as tracks for organelles to move along within the cell

3. They form the centriole

1. This consists of two bundles of microtubules at right-angles to each other

2. Each bundle contains 9 tubes in a very characteristic arrangement

3. At the start of mitosis and meiosis, the centriole divides, and one half moves to each end of the cell, forming the spindle

4. The spindle fibres are later shortened to pull the chromosomes apart

Cilia and flagellae

1. Cilia and Flagellae are structures that project from the cell, where they assist in movement

2. Cilia (sing. cilium) are short, and numerous and hair-like

3. Flagellae (sing. flagellum) are much longer, fewer, and are whip-like

4. The cilia and flagellae of all Eukaryotes are always in a '9 + 2' arrangement that is characteristic (see diagram)

5. Protoctista commonly use cilia and flagellae to move through water

6. Sperm use flagellae (many, all fused together) to swim to the egg

7. Cilia line our trachea and bronchi, moving dust particles and bacteria away from the lungs

Plant cell structures

1. Most of the organelles and other parts of the cell are common to all Eukaryotic cells. Cells from different organisms have an even greater difference in structure

2. Plant cells have three additional structures not found in animal cells:

1. Cellulose cell walls

2. Chloroplasts (and other plastids)

3. A Central Vacuole

Cellulose cell wall

1. One of the most important features of all plants is presence of a cellulose cell wall.

2. Fungi such as Mushrooms and Yeast also have cell walls, but these are made of chitin.

3. The cell wall is freely permeable (porous), and so has no direct effect on the movement of molecules into or out of the cell.

4. The rigidity of their cell walls helps both to support and protect the plant.

5. Plant cell walls are of two types:

1. Primary (cellulose) cell wall - While a plant cell is being formed, a middle lamella made of pectin, is formed and the cellulose cell wall develops between the middle lamella and the cell membrane. As the cell expands in length, more cellulose is added, enlarging the cell wall. When the cell reaches full size, a secondary cell wall may form

2. Secondary (lignified) cell wall - The secondary cell wall is formed only in woody tissue (mainly xylem). The secondary cell wall is stronger and waterproof and once a secondary cell wall forms, a cell can grow no more - it is dead!

1. The most prominent structure in plant cells is the large vacuole.

2. The vacuole is a large membrane-bound sac that fills up much of most plant cells.

3. The vacuole serves as a storage area, and may contain stored organic molecules as well as inorganic ions.

4. The vacuole is also used to store waste. Since plants have no kidney, they convert waste to an insoluble form and then store it in their vacuole - until autumn!

5. The vacuoles of some plants contain poisons (eg tannins) that discourage animals from eating their tissues.

6. Whilst the cells of other organisms may also contain vacuoles, they are much smaller and are usually involved in food digestion.

Chloroplasts (and other plastids)

1. A characteristic feature of plant cells is the presence of plastids that make or store food.

2. The most common of these (some leaf cells only!) are chloroplasts - the site of photosynthesis.

3. Each chloroplast encloses a system of flattened, membranous sacs called thylakoids, which contain chlorophyll.

4. The thylakoids are arranged in stacks called grana.

5. The space between the grana is filled with cytoplasm-like stroma.

6. Chloroplasts contain ccc DNA and 70S ribosomes and are semi-autonomous organelles.

7. Other plastids store reddish-orange pigments that colour petals, fruits, and some leaves.

Multicellular organization

In a unicellular organism, one cell carries out all of the functions of life. In contrast, most cells in a multicellular organism are specialized to perform one or a few functions - more efficiently. Because of cell specialization, the cells of multicellular organisms depend on other cells in the organism for their survival.

Tissue, organs, and organ systems

1. In most Multicellular Organisms, we find the following organization:

Cellular Level: The smallest unit of life capable of carrying out all the functions of living things.

Tissue Level: A group of cells that performs a specific function in an organism.

Organ Level: Several different types of tissue that function together for a specific purpose.

Organ System Level: Several organs working together to perform a function. The different organ systems in a multicellular organism interact to carry out the processes of life

2. Plants also have tissue and organs, although they are arranged somewhat differently from those of animals - e.g. vascular tissue.

3. The four plant organs are: Roots Stems Leaves and Flowers

Colonial organizations

1. A colonial organization is a collection of genetically identical cells that live together in a closely connected group.

2. Many of the cells of the colony carry out specific functions that benefit the whole colony.

3. Colonial organisms (e.g. sponges, coral) appear to straddle the border between a collection of unicellular organisms and a true multicellular organism. They lack tissues and organs, but do exhibit the principle of cell specialization.

This page has been written by Ian White.

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Both living and non-living things are composed of molecules made from chemical elements such as Carbon, Hydrogen, Oxygen, and Nitrogen. The organization of these molecules into cells is one feature that distinguishes living things from all other matter. The cell is the smallest unit of matter that can carry on all the processes of life .

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Introduction to macromolecules (article) | Khan Academy

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Types of large biological molecules. Monomers, polymers, dehydration synthesis, and hydrolysis.

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Biology is the study of life. The word "biology" is derived from the Greek words "bios" (meaning life) and "logos" (meaning "study"). In general, biologists study the structure, function, growth, origin, evolution and distribution of living organisms.

Biology is important because it helps us understand how living things work and how they function and interact on multiple levels, according to the Encyclopedia Britannica. Advances in biology have helped scientists do things such as develop better medicines and treatments for diseases, understand how a changing environment might affect plants and animals, produce enough food for a growing human population and predict how eating new food or sticking to an exercise regimen might affect our bodies.

The basic principles of modern biology

Four principles unify modern biology, according to the book " Managing Science" (Springer New York, 2010):

1. Cell theory is the principle that all living things are made of fundamental units called cells, and all cells come from preexisting cells.

2. Gene theory is the principle that all living things have DNA, molecules that code the structures and functions of cells and get passed to offspring.

3. Homeostasis is the principle that all living things maintain a state of balance that enables organisms to survive in their environment.

4. Evolution is the principle that describes how all living things can change to have traits that enable them to survive better in their environments. These traits result from random mutations in the organism's genes that are "selected" via a process called natural selection. During natural selection, organisms that have traits better-suited for their environment have higher rates of survival, and then pass those traits to their offspring.

The many branches of biology

Although there are only four unifying principles, biology covers a broad range of topics that are broken into many disciplines and subdisciplines.

On a high level, the different fields of biology can each be thought of as the study of one type of organism, according to " Blackie's Dictionary of Biology" (S Chand, 2014). For example, zoology is the study of animals, botany is the study of plants and microbiology is the study of microorganisms.
Related: Plant photos: Amazing botanical shots by Karl Blossfeldt
Within those broader fields, many biologists specialize in researching a specific topic or problem. For example, a scientist may study behavior of a certain fish species, while another scientist may research the neurological and chemical mechanisms behind the behavior.

Biochemistry: The study of the chemical processes that take place in or are related to living things, according to the Biochemical Society. For example, pharmacology is a type of biochemistry research that focuses on studying how drugs interact with chemicals in the body, as described in a 2010 review in the journal Biochemistry.

Ecology: The study of how organisms interact with their environment. For example, an ecologist may study how honeybee behavior is affected by humans living nearby.

Genetics: The study of heredity. Geneticists study how genes are passed down by parents to their offspring, and how they vary from person to person. For example, scientists have identified several genes and genetic mutations that influence human lifespan, as reported in a 2019 review published in the journal Nature Reviews Genetics.

Physiology: The study of how living things work. Physiology, which is applicable to any living organism, "deals with the life-supporting functions and processes of living organisms or their parts," according to Nature. Physiologists seek to understand biological processes, such as how a particular organ works, what its function is and how it's affected by outside stimuli. For example, physiologists have studied how listening to music can cause physical changes in the human body, such as a slower or faster heart rate.

(Image credit: Shutterstock)

There are numerous branches and subdisciplines of biology, but here is a short list of some of the more broad fields that fall under the umbrella of biology:

Astrobiology is the study of the evolution of life in the universe, including the search for extraterrestrial life, according to NASA. This field incorporates principles of biology with astronomy.

Bioarchaeologists are biologists who incorporate archaeological techniques to study skeletal remains and derive insights about how people lived in the past, according to George Mason University.

Bioengineering is the application of engineering principles to biology and vice versa, according to the University of California Berkeley. For example, a bioengineer might develop a new medical technology that better images the inside of the body, like an improved MRI that scans the human body at a faster rate and higher resolution, or apply biological knowledge to create artificial organs.

Biotechnology involves using biological systems to develop products, according to the Norwegian University of Science and Technology. For example, biotechnologists in Russia genetically engineered a better-tasting and more disease-resistant strawberry, which the researchers described in their 2007 study published in the journal Biotechnology and Sustainable Agriculture 2006 and Beyond.

Biophysics employs the principles of physics to understand how biological systems work, according to the Biophysical Society. For example, biophysicists may study how genetic mutations leading to changes in protein structure impacts protein evolution.

The multidisciplinary nature of biology

Biology is often researched in conjunction with other fields of study, including mathematics, engineering and the social sciences. Here are a few examples:

Research: Biologists can perform research in many types of settings. Microbiologists, for instance, may study bacterial cultures in a laboratory setting. Other biologists may perform field research, where they observe animals or plants in their native habitat. Many biologists may work in the lab and in the field - for example, scientists may collect soil or water samples from the field and analyze them further in the lab, like at North Carolina University's Soil and Water Lab.

Healthcare: People who study biology can go on to work in healthcare, whether they work as doctors or nurses, join a pharmaceutical company to develop new drugs and vaccines, research the efficacy of medical treatments or become veterinarians to help treat sick animals, according to the American Institute of Biological Sciences.

Conservation: Biologists can help with efforts in environmental conservation by studying and determining how to protect and conserve the natural world for the future. For example, biologists may help educate the public on the importance of preserving an animal's natural habitat and participate in endangered species recovery programs to stop the decline of an endangered species, according to the U.S. Fish & Wildlife Service.

Art: Biologists who also have a background in art have both the technical knowledge and artistic skill to create visuals that will communicate complex biological information to a wide variety of audiences. One example of this is in medical illustration, in which an illustrator may perform background research, collaborate with experts, and observe a medical procedure to create an accurate visual of a body part, according to the Association of Medical Illustrators.

Additional resources:
What do biologists do?

Biologists can work in many different fields, including research, healthcare, environmental conservation and art, according to the American Institute of Biological Sciences. Here are a few examples:

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Biology is the study of life. The word "biology" is derived from the Greek words "bios" (meaning life) and "logos" (meaning "study"). In general, biologists study the structure, function, growth, origin, evolution and distribution of living organisms. Biology is important because it helps us understand how living things work and how they function and interact on multiple levels, according to the Encyclopedia Britannica.

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-Capillary: smallest blood vessel; brings nutrients and oxygen to the tissue and absorbs carbon dioxide and waste products
-Veins: blood vessels that carry blood from the body back to the heart
-Hypertension: high blood pressure
-Hemoglobin: iron-containing protein in red blood cells that binds oxygen and transports it to the body
-Atherosclerosis:  condition in which fatty deposits called plaque builds up inside artery walls and eventually cause the arteries to stiffen
-Gastrulation: process of cell migration that results in the formation of the three cell layers
-Pathogen: disease-causing agent
-Macrophage: a phagocytic cell found in a stationary form in the tissues or a mobile white blood cell, especially at sites of infection
-Lymphocyte: a form of small white blood cell with a single round nucleus
-Antibody: protein substance produced in the blood or tissues in response to a specific antigen that destroys or weakens bacteria and neutralizes organic poisons

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-carrying capacity: largest number of individuals of a particular species that a particular environment can support
-density dependent factors: limiting factor that depends on a population density
-biological magnification: increasing concentration of a harmful substance in organisms at higher trophic levels in a food chain or food web
-density independent factors: limiting factor that affects all populations in similar ways, regardless of population density
-immigration: movement of individuals into an area occupied by an existing population
-population density: numbers of individuals per unit area
-habitat fragmentation: splitting of ecosystems into species
-greenhouse effect: process in which certain gases trap sunlight energy in Earth's atmosphere as heat
-emigration: movement of individuals out of an area
-biodiversity: total of the variety of organisms in the biosphere

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-herbivore: organism that obtains energy by only eating plants
-carnivore: organism that obtains energy by only eating animals
-biogeochemicalcycle: process by which elements, chemical compounds, and other forms of matter are passed from one organism to another and from one part of the biosphere to another
-habitat: area where an organism lives, including the biotic and abiotic factors that affect it
-predation: interaction in which one organism (predator) captures and feeds on another organism (prey)
-omnivore: organism that obtains energy by eating both plants and animals
-detritivore: organisms that feeds on plants and animal remains and other dead matter
-trophic level: each step in a food chain or food web
-food chain: series of steps in an ecosystem in which organisms transfer energy by eating and being eaten
-food web: network of feeding interactions

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-photosynthesis: process used by plants and other autotrophs to capture light energy and use it to power chemical reactions that convert carbon dioxide and water to oxygen and energy rich carbohydrates
-cellular respiration: process that releases energy by breaking down glucose and other food molecules in the presence of oxygen
-xylem: vascular tissue that carries water upward from the roots to every part of the plant
-phloem: vascular tissue that transports solutions of nutrients and carbohydrates produces by photosynthesis through the plant
-stamen: make part of a flower; contains anther and filament
-pistil: single carpel or several fused carpels; contains the ovary, style, and stigma
-vascular tissue: specialized tissue in plants that carries water and nutrients
-dermal tissue: a thin layer of cells covering the soft parts of a plant
-stomata: small opening in the epidermis of a plant that allows carbon dioxide, water, and oxygen to diffuse in and out of the leaf
-transpiration: loss of water from a plant through its leaves

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-Evolution: change overtime; the process by which modern organisms have descended from ancient organisms
-Derived trait: is a trait that arose in the most recent common ancestor of a particular lineage and was paused along to its descendants
-Ancestral trait: character, trait, or feature of a lineage or taxon that is inherited from the common ancestor
-Homologous structure: structure that is similar in different species of a common ancestor
-Analogous structure: is the body parts that share the common function but not the same structure
-Vestigial structure: is inherited from the ancestors but have lost much or all of their original functions due to different selection pressures acting on the descendant
-Classification: a system that organized species into taxa that formed a hierarchy or a set of ordered ranks
-Phylogeny: the evolution history of a lineage
-Taxonomy: the branch of science concerned with classification especially of organsims
-Binomial nomenclature: a two-name naming system

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-Dominant: a dominant trait or gene
-Recessive: relating to heritable characteristics controlled by genes expressed in offspring only when inherited from both parents, when not masked by a dominant characteristic inherited from one parent
-Codominance: situation in which the phenotypes produced by both alleles are completely expressed
-Incomplete dominance: situation in which one allele is not completely dominant over another allele
-Monohybrid: a hybrid that is heterozygous with respect to a specified gene
-Transgenic: an organism that contains genes from other organisms
-Dihybrid: a hybrid that is heterozygous for alleles of two different genes
-Polygene: group of genes that produce a specific phenotype or trait only when expressed together
-Genetic engineering: the modification of the characteristics of an organism by manipulating its genetic material
-Pedigree: chart that shows the presence or absence according trait according to the relationships within a family across generations

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-Complementary Base: nucleotide bases linked together by a hydrogen bond on opposite strands of DNA or double-stranded RNA
-Thymine: a compound that is one of the four bases of nucleic acids
-Nucleic acid: an organic substance present in living cells, whose molecules consist of many nucleotides linked in a long chain
-Hydrogen bond: weak attraction between a hydrogen atom and another atom
-Cytosine: a compound found in living tissue as a base of nucleic acids
-Nucleotide: subunit oh which nucleic acids are composed; made up  of 5-carbon sugar, a phosphate group, and a nitrogous base
-Adenine: a compound that is one of the four bases of nucleic acids
-Guanine: one of the four bases of nucleic acids
-Replication: process of copying DNA prior to cell division

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-asexual reproduction: process of reproduction involving a single parent that results in an offspring that is genetically identical to the parent
-cell cycle: series of events in which a cell grows, prepares for division, and divides to form two daughter cells
-chromosomes: threadlike structure of DNA and protein that contains genetic information
-sister chromatid: two chromatids joined by a common centromere
-daughter cell: one of the two or more cells formed in the division of a parent cell
-diploid: cell that contains two sets of homologous chromosomes
-chromatin: substance found in eukaryotic chromosomes that consists of DNA tightly coiled
-binary fission: type of asexual reproduction in which an organism replicates its DNA and divides in half, producing two identical daughter cells
-cytokinesis: division of the cytoplasm to from two separate daughter cells
-cancer: disorder in which some of the body's cells lose the ability to control growth

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-cohesion: attraction between molecules of the same substance
-adhesion: The binding of a cell to another cell or a cell to a surface
-solute: substance that is dissolved in a solution
-solvent: dissolving substance in solution
-osmosis: diffusion of water through a selectively permeable membrane
-isotonic: when the concentration of two solutions are the same
-hypotonic: the solution with the lesser concentration of solutes
-hypertonic: the solution with the greater concentration of solutes
-diffusion: process by which particles tend to move from an area where they are more concentrated to an area where they are less consentrated
-enzyme: protein catalyst that speeds up the rate of specific biological reactions

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18 Things You Should Know About Genetics

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-cell membrane: thin, flexible barrier that surrounds all cells; regulates what enters and leaves the cell
-nucleus: structure that contains the cells's genetic material in the form of DNA
-eukaryote: organism whose cells contains a nucleus
-prokaryote: unicellular organism that lacks a nucleus
-cytoplasm: in eukaryotic cells it's all cellular content outside of the nucleus; in prokaryotic cells it's all of the cell's contents
-organelle: specialized structures that perform important cellular functions within a cell
-chloroplast: organelle found in plant cells or other organisms that capture energy from sunlight and converts it to chemical energy
-cell wall: strong, supporting layer around the cell membrane in some cells
-mitochondrion: the power house of the cell
-golgi apparatus: a complex of folded membranes within the cytoplasm of most eukaryotic cells, involved in transport

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-macromolecule: a molecule containing a very large number of atoms, such as a protein and nucleic acid
-molecule: a group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction
-protein: any of a type of nitrogenous organic compounds that consist of large molecules composed of one or more long chains of amino acids and are an essential part of all living organisms
-lipid: macromolecule made mostly from carbon and hydrogen atoms; includes fats, oils, and waxes
-carbohydrate: any of a big group of organic compounds occurring in foods and living tissues and including sugars, starch, and cellulose
-nucleic acid: an organic substance present in living cells, whose molecules consist of many nucleotides linked in a long chain
-amino acid: a simple organic compound containing both a carboxyl and an amino group
-fatty acid: an acid consisting of a hydrocarbon chain
-monomer: a molecule that can be bonded with other molecules to form a polymer
-polymer: molecules composed of many monomers; makes up macromolecules

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*Science of Biology
*Macromolecules
*Cell Structure & Function
*Cell Transport & Water Properties
*Mitosis
*DNA & Protein Synthesis
*Genetics & Biotechnology
*Evolution
*Plants
*Matter & Energy
*Population Ecology
*Human Body Systems
*Answers to Question Time
*Practice Test
*Practice Test Answers

# data[].attributes.body
-science: an organized way of gathering and analyzing evidence about the natural world
-observation: process of seeing and describing events or processes in a careful, orderly
-inference: a logical interpretation based on knowledge and experience
-hypothesis: possible explanation for a set of observations or possible answer to a scientific question
-theory: well-tested explanation that unifies a broad range of observations and hypothesis, and enables scientists to make accurate predications about new situations
-independent variable: factor in a controlled experiment that is changed
-dependent variable: variable that is observed and that changes in response to the independent variable
-control group: group in an experiment that is exposed to the same conditions as the experimental group except for one independent variable
-law: generalized rule explaining a body of observations in forms of a verbal or mathematical statement
-experiment: a test under controlled conditions that is made to demonstrate a truth or to examine the validity of a hypothesis

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9. How do plants make food?
A. Mcdonald's
B. the sun
C. Photosynthesis
D. buy food at Walmart

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10. What do carnivores eat?
A.plants
B.humans
C.animals
D.books

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Mitosis - Stages of Mitosis | Cells | Biology | FuseSchool

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Transport in Cells: Diffusion and Osmosis | Cells | Biology | FuseSchool

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1.  Is Biology classified in different        categories?
A-True

B-False

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3. What are cells made of?
A.Blood
B.Organelles
C.Cytoplasm
D.Water

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2. How many different amino acids   are there?

A.35
B.500
C.20
D.

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12. What does a pathogen cause?
A. death
B. disease
C. concussion
D. gastrulation

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8. Evolution is...
A. the change of something overtime
B. nothing
C. the change of music over time
D. is science

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11. What is emigration?
A.coming into
B. leaving
C. sleeping
D. eating

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6. What is the process of making protein?
A. science
B.mitosis
C.protein synthesis
d.evolution

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5. Cytokinesis is...
A.process in plants and animals
B.separation of cytoplasm, forming two cells
C. final stage of mitosis

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4. Does water expand when it   freezes?
A-No
B-Yes
C-IDK

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7. Chromosomes are...
A.made up of many genes
B. babies
C. a disease
D. plants