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Create a new document and edit with others at the same time -- from your computer, phone or tablet. Get stuff done with or without an internet connection. Use Docs to edit Word files. Free from Google.

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Create a new document and edit with others at the same time -- from your computer, phone or tablet. Get stuff done with or without an internet connection. Use Docs to edit Word files. Free from Google.

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How Your Body Systems are Connected - Revere Health | Live Better

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Each of your organs belongs to one of ten body systems. These body systems are interconnected and dependent upon one another to function. Learn more today!

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Many of the materials I have gone over in here involve working together towards a goal. Not only does all parts of the body work together, but the systems of each part. For example, the brain is split up into many different parts where each part is given a particular function. Each part has control over another body part. One body system connected to the brain/nervous system is the circulatory system. Veins and arteries are needed to pump blood and nutrients to all parts of the body. In addition, our immune system is also linked with the circulatory system. When we scrape or cut our hand, blood gushes out as well as platelets which prevent further bleeding by clotting. In a way, all of the parts in our body are connected.

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Expands knowledge on interactions between organisms such as mutualism and vulnerability of extinction

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Population ecology - Logistic population growth

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Population ecology - Logistic population growth: The geometric or exponential growth of all populations is eventually curtailed by food availability, competition for other resources, predation, disease, or some other ecological factor. If growth is limited by resources such as food, the exponential growth of the population begins to slow as competition for those resources increases.

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Goes over matter and the energy flow in an ecosystem as well as models that go along with it

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Chapter 9.3: Matter and Energy in Ecosystems

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Goes over types of seeds more and gives examples and visuals to go along with the explanation of the functions

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Biology4Kids.com: Plants: Mosses and Liverworts

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Biology4Kids.com! This tutorial introduces mosses. Other sections include animal systems, cells, vertebrates, and invertebrates.

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Links natural selection as well as anatomical structures and that all species are related by a common ancestor

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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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Gives the pros and cons of biotechnology based on ethics

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The progress of science in the 20th and 21st centuries exploded, creating technologies that reshaped society and extended lives. The pace of change was so great that it took society years to start asking questions about the ethics or morality of new developments. Now, humanity is at a major crossroads, where further investment in biotechnologies could change the way humans live and reproduce. However, the advancements may come at too steep a price.

In 2016, biotechnology engineers and researchers must address five core concerns that are the foundations of bioethics.

Use of Genetics

The Human Genome Project generated billions of dollars in funding in the 20th century, with the goal of creating a single depository of DNA base pairs and possible human genomes. On April 14, 2003, the project reached completion, and the genetic engineering field grew quickly.

Uncovering the human genome was a tremendous step forward for science, but the discovery created a series of new concerns.

Researchers have been able to use the information from the Human Genome Project to develop the new science of pharmacogentics, the study of how an individual's genes affect his or her body's ability to metabolize or react to a drug. The study of pharmacogentics aims to eliminate adverse drug events (ADE) and side effects by tailoring drugs specific to a patient's genome. While the new personalized medications can eliminate side effects, the use of genetic information to create medicine contributes to the rising cost of drugs, and shifts attention away from designing affordable drugs available for mass production.

The creation of designer babies is another critical bioethical issue for geneticists. Designer babies are children enhanced through gene manipulation to meet certain mental, physical, and emotional demands of parents. The technology does not yet exist to manipulate the entire genome of a fetus, but research continues along this path.

Stem Cells

Stem cells are the core of much biotechnical research. Because the stem cell lines can grow into any human tissue, they are invaluable for research into medicines and medical treatments, without putting people at risk. Eventually, scientists believe that stem cells may be used to grow new organs and reverse paralysis.

Almost all stem cells are the result of embryos fertilized in vitro and placed in frozen storage. Couples choose to use the embryos for implantation, though only a fraction of the embryos are ever implanted. As the cost of storage grows, couples must decide to destroy the embryo or donate them.

The use of stem cells, especially in the United States, is one of the most controversial issues in biotechnology. Supporters argue the embryos used to generate stem cell lines were going to be destroyed, and using them for research has the capacity to save untold numbers of lives. Opponents believe creating new lines from embryonic stem cells is akin to abortion, and the destruction of any embryo for research purposes is an ethical violation. Both sides have come to a partial agreement on the use of adult stem cells over embryonic cells, but the adult cells offer far fewer options and less promising research.

Human Testing

As medical and biotechnology grow, so do the pressures for companies to bring new products to the market. The FDA's new drug pipeline is clogged with thousands of drugs making their way toward approval, though only about 12 percent will ever see mass production. The approval process can take up to 10 years, and the financial stress of seeking FDA approval is too much for many companies.

One of the biggest problems with the FDA approval process is the amount of time that drugs must spend in human clinical trials. Estimates show that a new drug can spend as long as seven years in human trials. Even when the drug completes the trial, it may not receive FDA approval.

Pharmaceutical companies are calling on the FDA to speed up the clinical trial portion of the approval process, greatly reducing the time spent in the drug pipeline and increasing the profits to be made. Reducing the approval time is a double-edged sword. Medications that work will begin helping patients much sooner, but rushing through the process removes safeguards put in place to keep the public safe.

GMO Food

A growing global population, concerns about diminished drinking water reserves, and a need to keep food affordable all prompted biotechnology engineers to expand the availability of genetically modified organisms (GMOs) in the food supply. The GMOs are cheaper to produce and heartier than unmodified food, allowing farmers to meet global food needs and maintain profits.

The backlash against GMOs has been strong, and grows every day. Opponents of GMOs claim the organisms actually put the entire food supply at risk through the homogenization of plant life and the death of biodiversity. They also argue that insects and plant-destroying bacteria or diseases will continue to evolve with the GMOs, resulting in superpests and superdiseases that are untreatable by modern methods. Finally, doctors argue that GMOs include antibiotics that make their way into the human body. Overconsumption of antibiotics is harmful, because those drugs lose their ability to fight off disease.

Costs

Developments in new drugs, instruments that improve the quality of life, and extend life expectancy to new highs are all lofty goals, but they come at a significant price. The cost of health care in the United States continues to grow, largely because of innovative medical treatments and drug options. Every year more families go bankrupt trying to pay for treatments made available through biotechnology, and there seems to be little sign of lower prices in the future.

The newest designer drugs will cost patients tens of thousands, if not hundreds of thousands of dollars a year. Biotechnology engineers and companies must find a way to address cost issues and make new advancements more affordable for the average consumer; otherwise, biotechnology will create a two-tiered society: those who can afford the medical treatments needed to live, and those who cannot.

Legal Implications of these Issues

Ethical concerns of biotechnology engineering have a broad impact, influencing a number of differing careers and industries. For example, moving forward it will be essential for entrepreneurs and biotechnology companies understand the ethical and legal implications within this field so that they make well-educated decisions while still remaining innovative. The health and pharmaceutical industries are also influenced by these concerns, particularly in regards to GMO foods and human testing. Individuals and companies within these industries will greatly benefit from understanding the potential legal implications of their decisions as one wrong decision could result in a series of expensive lawsuits.

Ethics in biotechnology will always be a hot-button issue, and one the industry must take the time to discuss. Failure to do so may result in the defunding of critical projects and social backlash against important research.

To learn to speak the language of health law and distinguish your role as a leader with specialized health care compliance expertise, look to pursue a Hofstra Law online master's in health law and policy.

Sources
U.S. National Library of Medicine - Personalizing medicine with clinical pharmacogenetics EuroStemCell Physicians Committee National Library of Medicine - Genetically Modified Foods and Social Concerns The Wall Street Journal

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5 Ethical Concerns of Biotechnology Engineering

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The progress of science in the 20th and 21st centuries exploded, creating technologies that reshaped society and extended lives. The pace of change was so great that it took society years to start asking questions about the ethics or morality of new developments.

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A short, click-through animation about protein synthesis and the transcription/translation process

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Protein synthesis :: DNA from the Beginning

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Problem in Concept 21: RNA is an intermediary between DNA and protein, DNA from the Beginning.

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Further explains what happens in each stage and what happens during interphase.

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Ties in the role of the cell membrane and types of concentrations

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fluid-mosaic model). The most common molecule in the model is thephospholipid , which has a polar (hydrophilic ) head and two nonpolar (hydrophobic ) tails. These phospholipids are aligned tail to tail so the nonpolar areas form a hydrophobic region between the hydrophilic heads on the inner and outer surfaces of the membrane.

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Tells why water is like such because of its structure

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Water is found all throughout nature, and is a necessary component in nearly all organic reactions. It is the most abundant compound on the surface of the planet. The majority of water on Earth is sea water, and water is also present as solid ice and invisible gaseous clouds. All life on Earth requires water to survive, and it is speculated that extraterrestrial water may be a sign of life (or at least a precursor to life) elsewhere in the universe. Along with enabling life, water has an effect on non-living things, such as its weathering and erosion of rocks and soil. Water also acts as a heat sink, absorbing excess heat and buffering the Earth's temperature from extreme changes. Water is a vital part of any living system, from entire habitats down to individual cells. So what is water?

Chemical Properties of Water

Water (also known as H ₂ O) is a polar chemical compound containing one oxygen (O) atom and two hydrogen (H) atoms (as seen in the first figure.) These three atoms are bound together with covalent bonds, meaning they share their pairs of valence or outer electrons together. Each hydrogen atom is separately bound to the central oxygen atom and the oxygen also has two pairs of unshared electrons, giving one water molecule a total of four shared and four unshared valence electrons. Water molecules have a bent shape, with a 104.45° angle between the two hydrogens.

Despite sharing their electrons, water molecules are polar because the valence electrons are shared unequally between the oxygen and hydrogen atoms. Oxygen has a greater electronegativity than hydrogen does, meaning it is highly attracted to electrons, so it pulls more strongly on the shared electrons and keeps them closer to itself. This creates a dipole moment, i.e., two electrical poles. This unequal sharing of electrons means that the electrons' negative charges cluster at the oxygen end of the molecule, leaving the hydrogen end of the molecule to be partially positive while the oxygen end is partially negative. Water's polarity leads to it being adhesive to many other substances, and helps make it an excellent solvent.

Polar substances dissolve well in water as "like dissolves like," but nonpolar substances do not dissolve as readily (or at all.) A common example of this solubility is the dissolution of table salt (NaCl) into water to produce Na⁺ and Cl⁻ ions surrounded by water molecules with their positive and negative poles oriented towards or away from the ions depending on the ion's charge. When a polar solute such as a salt dissolves into positive and negative ions, the water molecules orient themselves to surround the individual ions and point their corresponding poles at the ion based on its charge; water's negative poles point at positive ions and vice versa.

When a nonpolar substance is mixed with water it does not dissolve but remains clumped together and as separate as possible from the water molecules. This is why water and oil remain separate when mixed together. Water is a good solvent of hydrophilic substances such as salts, while poorly dissolving hydrophobic substances such as fats and oils. A substance is unable to dissolve in water when its attraction to the water molecules does not outweigh their attraction to each other; it disrupts the water's intermolecular bonds without replacing them, and is therefore energetically unfavorable. A hydrophilic solute will, in contrast, be quickly surrounded by water molecules and form new tenuous bonds with them.

Water is an amphoteric compound, meaning it can act as a base or an acid in a chemical reaction. This allows it to participate in a large number of reactions, both in the laboratory and in nature. Water is also not easily compressible, meaning it cannot (as a liquid) be easily squeezed into a smaller volume. These various properties of water are very important in the life of the Earth and in the life of individual organisms.

Physical Properties of Water

Water is a liquid at standard temperature and pressure, but is also found in nature in its solid (frozen) and gaseous phases. Water's boiling point (the point at which it shifts from a liquid to a gas, or vice versa) is at 100° Celsius and its freezing point (at which it shifts from a liquid to a solid, or vice versa) is at 0°C. Water has a high heat capacity, which means it can absorb a great deal of energy without its temperature increasing greatly. Water also has a relatively high boiling point compared to the boiling points of similar compounds, meaning that more energy must be put into water to separate the molecules and turn it from a liquid into a gas. These two properties are due to its many intermolecular hydrogen bonds (discussed below in the Special Properties paragraph.)

In its pure state water is tasteless and odorless, however water is a universal solvent and therefore is often found with substances dissolved in it, changing its physical characteristics. Minerals and other impurities give bottled water its flavor, and it is the presence of solutes that gives water its ability to conduct electricity well. If water had no dissolved ions it would be a poor conductor of electricity. However, no water is completely free of ions and even in the absence of a solute it can auto- ionize to form negative hydroxide anions (OH⁻) and positive hydronium cations (H ₃O⁺.) These ions allow water to conduct some electricity even when it is pure or "deionized." Water's electrical conductance as well as water's propensity for dissolving hydrophilic substances both have great importance in chemistry and the biological sciences.

Special Properties of Water

Many of water's special properties are derived from hydrogen bonding. Thanks to their atomic composition and molecular shape, water molecules can be attracted to each other through hydrogen bonding. This weak bond occurs when a hydrogen atom covalently bound to a more electronegative atom is then briefly electrically attracted to a second highly electronegative atom on another separate molecule. The hydrogen acts like the sticky, attractive peanut butter between two pieces of electronegative bread. This brings the two molecules together through the hydrogen's dual attractions. In this way water molecules work like tiny magnets, their partially positive and negative poles interacting together via hydrogen bonds. Water molecules can form up to four hydrogen bonds each, creating a local tetrahedral structure of five hydrogen-bonded water molecules (as seen in the second figure.) Hydrogen bonding gives water its cohesion and surface tension, allowing it to cling to itself. It also greatly affects water's freezing behavior and density.

Liquid water's density is approximately 1 gram per cubic centimeter (1g/cm ³.) Unlike most substances, water is denser in the liquid phase than the solid phase; this is due to the water molecules forming a loose hexagonal crystalline structure as they cool and freeze together, locking them into an expanded and less dense form than their freely-moving liquid form. With freezing, the temporary hydrogen bonds between molecules are allowed to stabilize, creating a lattice of water molecules held slightly apart from each other. Because of this difference in density, solid ice can float on liquid water. Thanks to this property, and water's high heat capacity (good insulation), lakes and ponds on Earth freeze slowly from the top down and rarely freeze fully, allowing organisms in the unfrozen water to survive the winter.

Biological Properties of Water

In the body, the major components of cells such as proteins, DNA and organelles are all dissolved in water and the cell is filled with watery cytoplasm. This allows essential molecules to be transported fluidly throughout the cell. The shape of the cell itself is heavily influenced by the water in and around it; too much water and the cell can burst open or "lyse" and too little water and the cell will shrivel. Water's polar nature prevents the hydrophobic phospholipid molecules from floating apart, packing them together in round cell membranes to present as little surface to the water as possible. The nonpolar nature of cell membranes keeps them closed against water leaking between them. Water transport into and out of the cell is strictly regulated, and the components of water (oxygen and hydrogen) are both used in many cellular processes.

Water's ability to conduct electrical impulses as well as it's propensity for dissolving polar substances allow the nerve cells in our brains to communicate with one another via electrical and chemical signals. Water's high heat capacity insulates our bodies from drastic temperature changes. Water's chemical and physical properties contribute to all life on Earth at the planetary, organismal, cellular, and molecular levels.

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Water is found all throughout nature, and is a necessary component in nearly all organic reactions. It is the most abundant compound on the surface of the planet. The majority of water on Earth is sea water, and water is also present as solid ice and invisible gaseous clouds.

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Gives us information about the structure and how the cell is organized inside as well as the introduction of cells being discovered

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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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Tells us what scientists must do and follow when experimenting

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Learning about the scientific method is almost like saying that you are learning how to learn. The scientific method is a process used by scientists to study the world around them. It can also be used to test whether any statement is accurate. You can use the scientific method to study a leaf, a dog, an ocean, or the entire Universe.

We all have questions about the world. The scientific method is there to test if your answer was correct. You could ask, "Why do dogs and cats have hair?" One answer might be that it keeps them warm. A good scientist would then come up with an experiment to test whether the statement was accurate. BOOM! It's the scientific method in action. (OK, settle down.)

Just about everything starts with a question. Usually, scientists come up with questions by looking at the world around them. "What is that?" See that squiggly thing at the end of the sentence? A question has been born.

So you've got a scientist. When scientists see something they don't understand they have some huge urge to answer questions and discover new things. It's one of those scientist personality traits. The trick is that you have to be able to offer some evidence that confirms every answer you give. If you can't test your own answer, other scientists can't test it to see if you were right or not.

As more questions are asked, scientists build a foundation of answers. Once you have a lot of individual answers, it's time to organize. One of the cool things about science is that other scientists can learn things from what has already been established. They don't have to go out and test everything again and again. Science is special because it builds on what has been learned before.

The whole process allows the world to advance, evolve, and grow. All of today's advancements are based on the achievements of scientists who already did great work. For example, you will never have to show that water (H2O) is composed of one oxygen (O) and two hydrogen (H) atoms. Many scientists before you have confirmed that fact. It will be your job as a new scientist to take that knowledge and use it in new experiments.

Experimental evidence is used to confirm the answers in science. Results are validated (found truthful) when other scientists repeat experiments and come up with the same results. A history of evidence and validations show that the original statements were correct and accurate. It is a simple idea and the basis of all science. Statements must be confirmed with loads of evidence.

Scientists start with general observations and then make a hypothesis. A hypothesis is somewhere between a statement and a guess. It is a proposed explanation for something that was observed. One example of a hypothesis might be, "All flowers are yellow."

Once you have a scientific hypothesis, the fun can begin. You need to test the hypothesis with an experiment and a series of procedures. The trials and tests will lead to observations and data. The data is the evidence you can use to determine if the hypothesis was correct.

It is very important that the experiment is objective. You must use controls which are quantitative (based on values and figures, not opinions or emotions). Scientists can then examine the results and develop newer ideas. This process will lead to more observation and refinement of hypotheses. Science needs both ideas (the hypothesis) and facts (the quantitative results) to move forward.

So what about that first hypothesis? Are all flowers yellow? No they aren't. Why? We went outside and took a picture of a red flower. The existence of one red flower means the original hypothesis was incorrect. A curious scientist might make another hypothesis that says all flowers are red or yellow. You could test that hypothesis by looking at a larger variety of flowers.

There are different terms used to describe scientific ideas based on the amount of confirmed experimental evidence.

Hypothesis - a statement that uses a few observations
- an idea or proposition based on observations without experimental evidence
Theory
- uses many observations and has loads of experimental evidence
- can be applied to unrelated facts and new relationships
- flexible enough to be modified if new data/evidence introduced
Law
- stands the test of time, often without change
- experimentally confirmed over and over
- can create true predictions for different situations
- has uniformity and is universal

You may also hear about the term "model." A model is a scientific statement that has some experimental validity or is a scientific concept that is only accurate under limited situations. Models do not work or apply under all situations in all environments. They are not universal ideas like a law or theory. Climatologists use many models to predict climate changes. Each model is dependent on specific variables and situations.

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Learning about the scientific method is almost like saying that you are learning how to learn. The scientific method is a process used by scientists to study the world around them. It can also be used to test whether any statement is accurate.

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Goes over all of the systems and further explains the process.

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Human Body Systems Functions Overview: The 11 Champions (Older Video 2016)

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There are many factors that affect organisms and their population. Two main ones are called abiotic factors and abiotic factors. Abiotic factors are nonliving factors while biotic factors are living factors. In addition to that, there are those factors that limit the population size of a species. For example, the carrying capacity limits the population because of predation or competition over food. Natural disasters like hurricanes or floods can affect the population (density independent factors.) This factor affects all populations instead of just one. It's not only nature that impacts the environment, but humans as well. This is called ecological footprint. This may be because of construction, fishing, farming, etc.

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How an organism obtains their energy can also classify them. They will be called a herbivore, omnivore, carnivore, or a detritivore. Then, they will be shown in food chains, webs or trophic levels. The bottom represents the primary producers, then the next, the primary consumers (herbivores), and after that, the secondary consumers (carnivore), and sometimes, the tertiary consumer (omnivore/carnivore.) The energy flow in the food chain or web is determined by where the arrow points. The arrow determines where the energy goes. In a food pyramid, 10% of the level below it has their energy donated to the next. There tends to be more of the organisms at the bottom that at the top.

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Just like the cell, parts of the plant also works as a whole to function. The plant starts off as a seed (monocot or dicot) and will soon grow roots. These roots absorb nutrients and water from the soil. The stem will eventually sprout, supporting the plants. Soon, leaves form and these help the plant produce even more food through the process of photosynthesis. Now comes the flower, which benefits reproduction. The bright, lovely colors of the petals attract pollinators such as bees or hummingbirds who will then pollinate the flower as they move from one to another. The seeds will then grow in the ovules and when ready fall out. As the plant grows, life becomes easier for them.

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Way far back, during the period with the dinosaurs, organisms were much different compared to today. That is because of evolution and the changes brought upon those species. Natural selection seems to play a huge role in evolution. Some of the offspring may be born with a beneficial trait that soon gets passed down and new changes form in the future. This leads to a change in physical appearance. Looking back, we can link some modern day animals with past organisms. We can do this by observing structures (vestigial, analogous, and homologous) and their embryos. Noticing a pattern and seeing similarities may indicate that the two are related.

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Usually, the offspring naturally receives genes and inherits traits from their parents. The offspring comes out as whatever without the parents choice. Let's say the parents want a brunette daughter with blue eyes, but unfortunately, both parents have brown eyes and are unable to produce a blue eyed child. As technology evolves, we have come to the point in time where we are able to customize organisms. Cloning, GMO plants and animals and gene therapy are examples of biotechnology. The benefits of these are more food is being produced and disorders are being treated. However, there are a few drawbacks such as less genetic variation, possibility of invasive species, and a risk of messing up someone's genes that can harm them.

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When an embryo changes into a gastrula

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When fatty substances form on the arteries walls

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The pigment that gives red blood cells their color

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When a person has high blood pressure

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A blood vessel

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Branching vessels/tubes taking blood from various parts to the heart and back

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Any disease producing agent

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A large white blood cell

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A type of white blood cell surrounded by cytoplasm

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Molecules that fight off bacteria or germs

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The mass of cells before the formation of a blastula

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The blastula of the embryo

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Talks about what can affect population size (population ecology)

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Talks about energy flow in an environment

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More about function and structure about plants

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Explains how all animals are related due to a common ancestor

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Talks a bit about genetics, then goes into customizing organisms and the benefits.

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Genetic Engineering Will Change Everything Forever – CRISPR

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Explains the process of the scientific method as well as some examples

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The Scientific Method: Steps, Terms and Examples

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A rap that presents the structure along with the function in a catchy and memorable way

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Adds onto the list of properties of water as well as tying in plants

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Talks about passive, andactive transport as well as diffusion and osmosis.

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Cell Transportation-Passive and Active Transport

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Visual animation with engaging pictures that further explains the information behind the stages. It talks about what may happen if it replicates incorrectly.

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Visual animation that shows the process of DNA to protein.

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DNA, known as deoxyribonucleic acid is the carrier of genetic instructions. Information (adenine, guanine, cytosine, thymine)is stored into DNA into chromosomes in the nucleus which contains the genes.
Protein synthesis goes from DNA, to RNA, to protein. In transcription, DNA is made into RNA by the complementary base paring (A=T, G=C.) In translation, RNA is then transformed into RNA protein. Here is when you translate the mRNA into the amino acid. You read each codon (three letters) then put the opposite, but in RNA, uracil replaces thymine.

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Cell transport and Water Properties Summary

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Cell transport and Water Properties Summary

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As said before, the cell membrane decides what enters or exits the cell. the layers that make up the cell membrane is the phospholid bilayer in which it has a water loving (hydrophilic) and water fearing (hydrophobic) tails. the phospholid bilayer transports proteins and helps molecules enter and exit the cell. This is where water comes into play known as osmosis or diffusion. In a hypertonic solution, water is high inside the cell, whereas, the water is higher outside the cell in a hypotonic solution. If water inside and outside are the same, it is an isotonic solution.
Water is more than just a liquid. Due to it being cohesive and adhesive, it's what makes water stick to other molecules. Bounded by hydrogen bonds, this creates surface tension, allowing it to resist external forces and some bugs to walk on the surface. In fact, water is the ultimate solvent because of its ability to dissolve many kinds of molecules.

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Cells, the basic unit of life, also contains a system within. Plant and animal cells have many differences in its structure. Since plants and animals obtain their food differently, the cells are different. Plant cells contain a cell wall and chloroplast to help them with photosynthesis. In addition, they have large vacuoles to store necessary materials. Both cells contain a cell membrane which protects the cell as well as a nucleus, cytoplasm and mitochondria. In the very center of the cell lies the nucleus, containing the cell's DNA, and in the space within the cell lies jelly-like fluid known as the cytoplasm. In the mitochondria, cellular respiration takes place. Food is broken down into energy that is used by the cell in the future. All parts of the cell work together like a team to maintain homeostasis.

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The scientific method has 7 steps to it. First, you have to ask yourself a question, and from there, you do some research. Soon, this leads to the formation of a hypothesis: a testable explanation based off limited knowledge. From there, an experiment occurs involving a control group in which data can be compared, an experimental group, independent variables and the dependent variables. After the experiment, the data is analyzed and thus the conclusion is made. After that, the experimenter then must report and compare results with others. Sometimes, this develops in a theory or law. However, both are not the same, a theory explains why something happens, whereas, a law explains how something happens and is a confirmed fact.

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Where meosis occurs

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Will remember virus/bacteria that is harmful and will respond more quickly to it.

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Defends against some viruses, fungi, and single celled pathogens

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Body cells that contain antigens are destroyed

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Consumes virus and displays antigen on its surface

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Macrophages
B-Cells (Humoral response)
T-Cells (Cell-Mediated Response)
Memory B-Cells and T-Cells

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Microorganisms are commonly called "germs" which cause physiological changes that disrupted normal body functions.
Caused by:
- viruses
- bacteria
- fungi
- parasites
- protists

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-Plasma: Straw colored fluid
-Red blood cells: (erythrocytes) transports oxygen & nutrients
-White blood cells: (leukocytes) defends against diseases
-Platelets: important in blood clotting

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Blood comes from the upper body to the heart by the way of the superior vena cava and from the lower body by the way of the inferior vena cava. The blood is now in the chamber (right atrium.) From here, it goes through the tricuspid valve into the right ventricle. Blood is now pumped to the lungs through the pulmonary semilunar valve by the way of the pulmonary artery. From the lungs, it is returned to the heart by the pulmonary veins and enters the left atrium. Blood then goes through the bicuspid (Mitrial) valve to the left ventricle. This is the main pump chamber of the heart. From here, blood is pumped through the aortic semilunar valve into the aorta, which is the largest blood vessel in the body. Blood is pumped to the rest of the body in arteries which brand into smaller vessels called arterioles, then through the capillaries which is where gases and wastes are exchanged. Blood then gathers in venules which leads to the veins which return blood to the heart.

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Blue = deoxygenated blood
red = oxygenated blood

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Connects nervous system to brain

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A center for respiration and circulation

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Function: Message station (body parts and brain)

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Function: produces hormones

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Function: controls movement and speed

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Connects left and right hemispheres

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Function: hearing, memory, meaning and language

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Function: vision, processing

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Function: touch, pain, taste, pressure, and temperature

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Functions: Emotions, reasoning, planning

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Human impact on environment

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Going out of the population range

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Coming into the population range

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Factors that affect population size based on population density
(e.g. competition, herbivory, parasitism, disease)

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Factors that affect all populations in similar ways regardless of density and population size
(e.g. hurricanes, wildfires, droughts, floods, etc.)

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-Birth rate
-Death rate
-Density (in)dependent factors
-Immigration
-Emigration
-Carrying capacity
-Ecological footprint

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Age ranges

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Study of statistics regarding the human population

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Study of how the population size changes overtime

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Totally amount of living tissue

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Pyramid of the feeding relationship among organisms
- Only 10% of energy is transferred in biomass to the next trophic level

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Feeding or energy position in an ecosystem
Trophic Levels
Primary Producer: Makes own food
Primary Consumer: Feeds on producers
Secondary Consumer: Feeds on primary consumers
Tertiary Consumer: Feeds on secondary consumers

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Organism that obtains their energy from dead/decayed material

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Organisms that obtain their energy from both plants and animals

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Organisms that obtain their energy by eating other animals

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Organisms that obtain their energy from plants

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A natural interconnection of food chains.

-arrows point to where the energy flows

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Movement of water in the biosphere
- Evaporation
- Transpiration
= Condensation
- Precipitation
- Surface run-off
- Ground water

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Movement of carbon in the biosphere
1) Carbon Reservoirs (storage)
- Decaying organisms
- Ocean sediments
- Buried fossil fuels
- Plants (by photosynthesis)
2) Atmosphere carbon
- Cellular Respiration
- Fossil fuel emissions

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How chemicals are recycled
e.g. water cycle

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Nonliving factors that affect organisms
e.g. Water, sunlight, soil, wind, pH, water currents

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factors that affect organisms (living)
e.g. animals, plants, bacteria, fungi, etc.

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Biosphere: All life on Earth
Biome: Similar climates
Ecosystem: Organisms and environment
Community: Populations in defined area
Population: Same species and same area
Species: Breed and reproduce

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Found in thylakoid sacks; pigment that absorbs light
-reflects green light

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embryo and endosperm (food) and seed coat

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Contains eggs that develop into seed

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Protects the ovule (fruit)