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Question 1

Biology can be defined as:

Answer 1

The scientific study of life.

Question 2

What is science? Please explains the different phases of the scientific method.

Answer 2

Science is an approach to understanding the natural world that is based on inquiry, a search for information, evidence, explanation, and answers for specific questions.

1. Exploration:
   
   • Making observations
   • Asking questions
   • Seeking information
2. Testing
   
   • Forming hypotheses
   • Making predictions
   • Running experiments
   • Gathering data
   • Interpreting data
   • Drawing conclusions
3. Communication
   
   • Sharing data
   • Obtaining feedback
   • Publishing papers
   • Replication findings
   • Building consensus
4. Outcomes
   
   • Building knowledge
   • Solving problems
   • Developing new technologies
   • Benefiting society

Question 3

Please explain the difference between a theory and a hypothesis.

Answer 3

• A theory is backed up by a wealth of evidence.

- A hypothesis is a proposed explanation for a set of observations that is testable and falsifiable.

Question 4

What is pseudoscience? How can you distinguish science from pseudoscience?

Answer 4

• Pseudoscience is falsely presented as having scientific evidence.
• It will have anecdotal evidence that is based a single or a few examples that do not support a general conclusion.

Question 5

The 8 properties of life are:

Answer 5

• Order
• Cells
• Growth and Development
• Energy Processing
• Regulation
• Response to Environment
• Reproduction
• Evolution

Question 6

Please list and explain the 5 major themes in biology.

Answer 6

1. Structure & Function: Structure (the shape of something) and function (what it does) are often related.
2. Information Flow: Information must be received, transmitted, and used.
3. Pathways that transform energy + matter: Movement, growth, reproduction, and the various cellular activities of life are work, and work requires energy. The input of energy, primarily from the sun, and the transformation of energy from one to another make life possible. Most ecosystems are solar powered at their source. Producers absorb the sun’s energy to chemical energy > organisms use it as food by breaking down chemical bonds. Decomposers break down waste products.
4. Interactions between biological systems: Biosphere (All life & places life exist) > Ecosystems (All living organisms & non living components in an area & environment) > Communities (All organisms in an ecosystem) > Populations (Groups of interacting individuals of one species within communities) > Organisms (Individual living things) > Organ Systems (Part of an organism and hold organs) > Tissues (Make up each organ; a group of similar cells performing a specific function) > Cells (The smallest unit that can display all characteristics of life) > Organelles (Functional components of cells) > Molecules (Clusters of even smaller chemical units called atoms).
5. Evolution: Evolution refers to how similar (unity) and different (diversity) life is. It’s the fundamental principle of life and the core theme that unifies all of biology. “Decent with Modification”: “Unity of Life” Decent from Common Ancestor & “Diversity of Life” Modifications that evolved as the species devolved from their ancestors. The process of natural selection is the driving force of natural selection. Population with varied traits > elimination of individuals with certain traits > reproduction of survivors > increasing frequency of traits that enhance survival and reproduction success.

Question 7

Please order the levels of life, with 1 being the largest and 12 being the smallest.

Populations, Atoms, Organisms.
Organ Systems, Tissues, Communities.
Biosphere, Organs, Cells.
Molecules, Organelles, Ecosystems.

Answer 7

1. Biosphere
2. Ecosystems
3. Communities
4. Populations
5. Organisms
6. Organ Systems
7. Organs
8. Tissues
9. Cells
10. Organelles
11. Molecules
12. Atoms

Question 8

The lowest level of structure that can perform all activities required for life is a(n) ___?

Answer 8

Cell.

Question 9

Matter can be defined as:

Answer 9

Anything that occupies space and has a mass.

Question 10

The 4 elements that make up 96% of the weight of the human body are:

Answer 10

Hydrogen, Oxygen, Nitrogen and Carbon.

Question 11

A(n) ___ is the smallest unit of matter that still retains the properties of an element.

Answer 11

Atom.

Question 12

6
C
12

Imagine this is in a square and on the periodic table, what does each symbol represent?

Answer 12

6 - Atomic Number (Number of Protons)
C - Element Symbol
12 - Atomic Mass (Mass of average atom of that element)

Question 13

Compare the 3 main subatomic particles:

Proton
Electron
Neutron

Please identify each’s electrical charge and location in atom.

Answer 13

Proton - (+) charge & located in nucleus
Electron - (-) charge & located in electron cloud
Neutron - No charge & located in nucleus

Question 14

_____ are alternate mass forms of an element because they have a different number of ____.

Answer 14

Isotopes, neutrons.

Question 15

Please define a chemical reaction. What are the names of the starting materials and end materials involved in any chemical reaction?

Answer 15

• A chemical reaction is a change in chemical composition.
• It begins with “reactants” and ends with “products”.
• Chemical reactions cannot create or destroy matter; they can only rearrange it.

Question 16

A(n) ____ is a chemical compound that releases H+ into solution, whereas a(n) ____ accepts H+ and removes it from a solution. A(n) ____ is a substance that resist pH changes.

Answer 16

Acid, base, buffer.

Question 17

Please list and compare the 3 main types of chemical bonds:

Answer 17

Ionic Bond: It’s the attraction between oppositely charged ions. By atoms gaining or losing electrons, they become electrically charged “ions”. If an ion is (+) it’s a cation, if an ion is (-) it’s an anion. For example, sodium ion (Na+) and the chloride ion (Cl-) are held together by an ionic bond.
Covalent Bond: Forms when two atoms share one or more pairs of electrons. Holds atoms together in a molecule. Result in a molecule. For example, CH2O.
Hydrogen Bond: A polar molecule has an uneven distribution of charge that creates two poles, one (+) and one (-). These are weak attractions. For example, hydrogen bonding in water. The oxygen is a bit greedy, so it gets a slightly more (-) charge and Hydrogen gets a slight (+) charge.

Question 18

Please list and compare the 4 life-supporting properties of water:

Answer 18

The Cohesive Nature of Water: The tendency of molecules of the same kind to stick together, is cohesion. It’s much stronger in water than in most other liquids. Surface tension is related to cohesion. Surface tension is the measure of how difficult it is to stretch or break the surface of a liquid. Hydrogen bonds give water unusually high surface tension, making it behave as if it were coated with invisible film. This explains why insects can walk on water, but they would, for example, not be able to walk on gasoline.
The Ability of Water to Moderate Temperature: Water has a stronger resistance to temperature change than most other substances. Water’s resistance to temperature stabilizes ocean temperatures, creating a favourable environment for marine life. Evaporative cooling helps some land-dwelling creatures from overheating, which dissipates excess body heat.
Heat is used first to break hydrogen bonds rather than raise temperature, so water absorbs and stores a large amount of heat while warming up only a few degrees. When water cools, hydrogen bonds form in a process that releases heat. Water can release a large amount of heat and the water will only drop slightly.
The Biological Significance of Ice Floating: When most liquids get cold, their molecules get closer, and they form a solid. Water is different; when molecules get cold enough, they move apart, at an “arm’s length” from its neighbour and forming ice. Ice floats because it is less dense than the liquid water it’s floating in. Floating ice is due to hydrogen bonding. (Hydrogen bonds in ice last longer than those in liquid water.) When a deep body of water cools and a layer of ice forms on top, the floating ice acts as an insulating “blanket” over the liquid water, allowing life to persist under the frozen surface. If ice were denser than water, it would sink during winter. They would freeze solid and, in the summer, only the top few inches would thaw.
The Versatility of Water as a Solvent: When water is the solvent, it’s called an “aqueous solution”. Water can dissolve in an enormous variety of solutes necessary for life, providing a medium for chemical reactions.

Question 19

A ___ is a simple organic compound containing only carbon and hydrogen.

Answer 19

Methane.

Question 20

Please define and give an example of a functional group.

Answer 20

• The groups of atoms directly involved in chemical reactions are called functional groups.
• Examples of functional groups are -OH, which is a hydroxyl group, and -COOH, which is a carboxyl group.

Question 21

_____ are made by stringing together many smaller molecules called _____.

Answer 21

Polymers, monomers.

Question 22

A _____ reaction links two monomers together by removing a molecule of ____. Contrarily, ____ breaks these bonds by adding a molecule of ____.

Answer 22

Dehydration, water, hydrolysis, water.

Question 23

Please define and give an example of an isomer.

Answer 23

• Molecules that have the same molecular formula but different structures.
• Examples of isomers with the formula C8H10 are ethyl benzene, m-xylene, p-xylene, and o-xylene.

Question 24

Humans use _____ to fuel our cells.

Answer 24

Carbohydrates.

Question 25

____ is the most abundant organic compound on Earth.

Answer 25

Carbon.

Question 26

What are 3 essential functions of fat in the human body?

Answer 26

• Stores energy.
• Cushions vital organs and insulates us.
• Helps us maintain a constant, warm body temperature.

Question 27

_____ is a process of converting unsaturated fats to saturated fats by adding ____.

Answer 27

Hydrogenation, hydrogen.

Question 28

Testosterone and estrogen are _____ that are derived from _____.

Answer 28

Steroids/hormones, cholesterol.

Question 29

Please list the 5 major types of proteins and give an example of where you could find each of these proteins.

Answer 29

1. Structural Proteins (provide support): Hair, ligaments, and horns.
2. Storage Proteins (provide amino acids for growth): Seeds and eggs.
3. Contractile Proteins (help movement): Enable muscles to contract.
4. Transport Proteins (help transport substances): Red blood cells have hemoglobin protein, which transports oxygen.
5. Enzymes (help chemical reactions): Cleaning products use enzymes to break down molecules.

Question 30

Amino acids have different ____ because of the variation in side groups. For examples, amino acids with a ____ side group cannot mix with water, in contrast to ____ side groups.

Answer 30

Chemical properties, leucine, serine.

Question 31

Please list and explain the 4 different levels of protein structure.

Answer 31

• Primary: The sequence of amino acids.
• Secondary: The formation of alpha helices and beta sheets.
• Tertiary: The folding of a polypeptide into its final three-dimensional shape.
• Quaternary: The joining of more than one chain to form a larger complex.

Question 32

In DNA, _ always pairs with _ and _ always pairs with _. These nitrogenous bases are connected by a ____ to form the double helix shape of DNA.

Answer 32

A, T, C, G, hydrogen bond.

Question 33

For each, please list their monomer, their typical components, their subgroups and examples.

Carbohydrates, Lipids, Proteins, and Nucleic Acids.

Answer 33

Carbohydrates: Monosaccharides (monomer), Carbon, Hydrogen, Oxygen (typical components), Monosaccharides, Disaccharides, Polysaccharides (Subgroups), Glucose/Fructose/Galactose (examples - monosaccharides), Lactose/Sucrose (examples - disaccharides), Starch/Glycogen/Cellulose (examples - polysaccharides).

Lipids: No monomers, a glycerol backbone, 2 [hydrophobic] fatty acid tails and a [hydrophilic] phosphate group (typical components), fats, steroids (subgroups), Saturated Fats/Unsaturated Fats/Trans Fats/Omega-3 Fats (examples - fats), Cholesterol/Testosterone/Estrogen (examples - steroids).

Proteins: Amino Acids (monomer), Carbon, Hydrogen, Nitrogen, and Oxygen (typical components), created by linking together amino acids into protein links called polypeptide chains, no subgroups, methionine, valine, leucine (examples).

Nucleic Acids: Nucleotides (monomer), 5-carbon sugar, phosphate group, and nitrogenous base (typical components), DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) (subgroups).

Question 34

Please list and briefly explain the two main processes of an ecosystem. You may use a diagram to supplement your answer but must explain it in words.

Answer 34

Energy flows through an ecosystem, entering as light energy and exiting as heat energy. It can also be recycled in the ecosystem.

Question 35

Please explain three of the levels of life and provide an example.

Answer 35

• A cell is the smallest unit that can display all the characteristics of life.
• An atom is the smallest unit of matter that still retains the properties of an element.
• The biosphere includes life and all the places inside of it.

Question 36

What is a controlled experiment? Please give a detailed example of a controlled experiment.

Answer 36

• A controlled experiment compares two or more groups that differ only in one variable that the experiment is designed to test.
• A control group lacks or does not receive the factor being tested. The experimental group has or receives the specific factor being tested.

Question 37

Why is carbon a versatile atom?

Answer 37

Carbon is versatile because it can form single, double, and triple bonds. It can also form chains, branched chains, and rings when connected to other carbon atoms.

Question 38

Please list the 4 large biological molecules. For each molecule, identify its monomer and explain its typical structure.

Answer 38

Carbohydrates, Lipids, Proteins, and Nucleic Acids. Their monomers are monosaccharides, no monomers, amino acids, and nucleotides, respectively.

Structures:

Carbohydrates consist of carbon, hydrogen, and oxygen. The general empirical structure for carbohydrates is (CH2O)n.

The structure of lipids is typically made of a glycerol backbone, 2 fatty acid tails (hydrophobic), and a phosphate group (hydrophilic).

The linear sequence of amino acids within a protein is considered the primary structure of the protein.

Nucleic acids are long chainlike molecules composed of a series of nearly identical building blocks called nucleotides. Each nucleotide consists of a nitrogen-containing aromatic base attached to a pentose (five-carbon) sugar, which is in turn attached to a phosphate group.

Question 39

Please list, describe the structure and provide and example for the three main subgroups of carbohydrates. What is an isomer?

Answer 39

• An isomer consists of the same formula but different arrangements.
• Monosaccharides are isomers, they have the formula C6H12O6 (for example, glucose and fructose).
• Disaccharides consist of two monosaccharides formed by a dehydration reaction (for example, glucose and galactose making lactose).
• Complex carbohydrates, or polysaccharides, are long chains of sugars, polymers of monosaccharides (for example, starch, long strings of glucose monomers).

Question 40

Please list, describe the structure and provide an example for the main subgroups of lipids. What is hydrogenation?

Answer 40

• Hydrogenation is a process of converting unsaturated fats to saturated fats by adding hydrogen.
• Fats consist of a glycerol molecule joined with three fatty acid molecules by dehydration reactions. A fatty acid is a long molecule (16 - 18 carbons) that stores a lot of energy. A fatty acid is unsaturated if it has fewer than the maximum number of hydrogens at the double bond. Saturated fatty acids contain the maximum number of hydrogen atoms, giving them a straight shape. A saturated fat is one with all three of its fatty acid tails saturated, if one or more of the fatty acids is unsaturated, then its an unsaturated fat. Food manufacturers convert unsaturated fats to saturated fats by adding hydrogen, a process called hydrogenation. Hydrogenation does create trans fats though, a type of unsaturated fat that is particularly bad for your health.
• Steroids have a carbon skeleton with four fused rings. One common steroid is cholesterol. A key component of the membranes that surround your cells, and is a “base steroid” which your body produces other steroids with, such as testosterone and estrogen.

Question 41

Please identify the similarities and differences in the 2 subgroups of nucleic acids.

Answer 41

• Both are polymers of nucleotides (a sugar + a nitrogenous base + a phosphate group).
• In RNA, the sugar is ribose; in DNA, it is deoxyribose.
• Both RNA and DNA have bases A, G, and C, but DNA has T and RNA has U.

Question 42

Please distinguish between the two major types of cells. Please list the three domains of life and state which types of cell they are composed of.

Answer 42

• Prokaryotes and eukaryotes.
• Prokaryotic cells evolved ~3.5 BYA, eukaryotic cells evolved ~2.1 BYA.
• Prokaryotic cells are found in bacteria and archaea. Eukaryotic cells are found in protists, plants, fungi, and animals.
• Prokaryotic cells are smaller and simpler, eukaryotic cells are larger and more complex.
• Prokaryotic cells: most have cell walls, some have capsules, fimbriae, and/or flagella. Eukaryotic cells: Plant cells have walls, animal cells are surrounded by an extracellular matrix.
• Both have a plasma membrane.
• Prokaryotic cells have no membrane-bound organelles, eukaryotic cells have membrane-bound organelles (e.g. nucleus, ER)
• Prokaryotic have a nucleoid region containing a single circular chromosome, eukaryotic cells have a nucleus containing one or more linear chromosomes.
• Both have ribosomes.

Question 43

Please explain the structure of the following organelles. How does the structure relate to its function?

Cell/Plasma Membrane:

Cell Wall:

Nucleus:

Cytoplasm:

Mitochondrion/Mitochondria:

Chloroplast:

Vacuole:

Lysosome:

Answer 43

Cell/Plasma Membrane: Surrounds cytoplasm/other organelles and allows things to enter/exit the cell/gets rid of waste.

Cell Wall: Rigid/surrounds plant cells and provides support/protection.

Nucleus: Houses chromosomes/DNA - the genetic code and is the control center, telling other organelles what to do.

Cytoplasm: Gel-like liquid that fills the cell and provides suspension to organelles so they move around easier.

Mitochondrion/Mitochondria: Double membrane organelle with inner folds and converts glucose molecules into energy.

Chloroplast: Filled with chlorophyll, contains stacks of discs, site of photosynthesis, which makes food for plant cells.

Vacuole: Much larger in plant cells than animal cells and is a storage site of water, nutrients, and waste.

Lysosome: Small, circular organelle that contains enzymes and digests old cell parts, aids in the removal of waste.

Question 44

What do chloroplasts and mitochondria have in common that no other organelle contains? What does this provide evidence for? Explain.

Answer 44

• Both provide cellular energy.
• Both contain their own DNA that encodes some proteins made by their own ribosomes. Each chloroplast and mitochondrion contains a single circular DNA chromosome that resembles a prokaryotic chromosome.
• In fact, mitochondria and chloroplasts can grow and pinch in two, reproducing themselves as many prokaryotes do.
• This indicates that they evolved from ancient free-living prokaryotes that established resident within older, larger host prokaryotes. This is a special kind of symbiosis. Over time, mitochondria and chloroplasts became increasingly interdependent with the host prokaryote, eventually evolving into a single organism with inseparable parts. The DNA within them likely includes remnants of this event.

Question 45

Please list the 5 main components of the endomembrane systems and provide their main functions.

Answer 45

1. The endoplasmic reticulum (ER): Connected to the nuclear envelope, it produces an enormous variety of molecules. It is made up of the rough ER and the smooth ER.
   
   • Rough ER: “Rough” refers to the ribosomes that stud the outside of its membrane. It functions to make phospholipids that are inserted into the ER membrane. The ER grows, and portions of it bubble off and are transferred to other parts of the cell. The ribosomes attached produce proteins that will be inserted into the ER membrane, transported to other organelles, then exported.
   • Smooth ER: “Smooth” refers to the lack of ribosomes that populate the rough ER. Diverse enzymes are built into the smooth ER membrane allows it to perform many functions, like synthesis of lipids, including steroids.
2. Golgi apparatus: It receives, refines, stores, and distributes chemical products of the cell. Products made in the ER (proteins) reach the Golgi apparatus in transport vesicles on it’s “receiving side”, then they are modified by enzymes to the “shipping side”. A new vesicle forms from the Golgi apparatus that transfer proteins or secrete finished products to the outside of the cell.
3. Lysosomes: A membrane-enclosed sac of digestive enzymes (made by rough ER and processed in Golgi apparatus). A lysosome can digest food by from food vacuoles with digestive enzymes (made from rough ER and processed in Golgi apparatus), can break down damaged organelles and recycle them to make new organelles, can destroy harmful bacteria and thereby, allow a cell to keep renewing itself.
4. Vacuoles: Large vesicles with a variety of functions. For example, food vacuoles can bud from the plasma membrane. Some freshwater protists have contractile vacuoles that pump out excess water that flows into the cell. There is also the central vacuole in the plant cell, a versatile compartment that can account for more than half the volume of a mature plant cell. It stores organic nutrients, and contributes to plant growth by absorbing water and expanding the cell.

5.