Bio 156 – Midterm Study Guide

Lesson One

I. Characteristics of Life

• List four main characteristics of all living things

II. Diversity and Organizing Life

• Describe three ways of classifying, or ordering, life on earth. • Given a random ordering of the levels of organization of life, rearrange them into the proper sequence. • Describe the concept "an organism is more than the sum of its parts." • List the six kingdoms of life. • By definition, distinguish between a population, a community, and an ecosystem. • Distinguish between a producer, a consumer and a decomposer.

III. Origins of Diversity- Evolution of Life

• Define the term "biodiversity. • Define the term "evolution." • Describe how diversity of life can arise by the operation of natural selection.

IV. The Nature of Biological Inquiry – Scientific Method

• Distinguish between a hypothesis and a prediction • Distinguish between inductive and deductive logic • What is meant by the phrase "potentially falsifiable hypothesis"? • Define the term "control group" and tell the value of a control group in an experiment • Define the term "theory" and tell at what point in a study a hypothesis becomes a theory • Design an experiment to test a given hypothesis, using the procedure and terminology of the scientific method. Try the problem: "Does temperature affect the breathing rate of a goldfish"? • Describe at least three ways that science differs from systems of belief that are based on faith, force or simple consensus.
Lesson 1 AYLs 1. How is the theory of evolution used to explain the tremendous diversity of life on Earth? Describe how variation within a population arises and how natural selection differs from artificial selection. Finally, describe how bacteria that become resistant to modern antibiotics is a clear example of evolution in action.

2. With the aid of specific examples, describe the concept of a hierarchy of biological organization. What is meant by the phrase, "The whole is greater than the sum of its parts?"

Sub atomic Particle--- Atom--- Molecule--- Organelle--- Cell--- Tissue---- Organ--- System--- Organism--- Population--- Community--- Ecosystem--- Biosphere......

3. Summarize the criteria of a hypothesis-based scientific study. How is this technique similar to and different from the solving of everyday problems? Research and describe an experiment of your choice that demonstrates the basic considerations that must be taken in the design of a good, hypothesis-based, scientific experiment.

4. What is biodiversity? Why is diversity of life forms important? Describe the major consequences to life on Earth from a loss of diversity.

5. What are the major characteristics of each of the three domains of life? Why do some researchers believe that the Kingdom Protista should be split into more than one kingdom?

Three domains are : Archaea, Bacteria, and Eukarya

Domains Archaea and Bacteria both include single-cell prokaryotes. Domain Eukarya includes all organisms made of eukaryotic cells

The evidence suggest that there was more than one common ancestor to the group at the level that it is separated from other groups. Ultrastructure, biochemical processes and molecular homology suggest that Protista comprises numerous subgroups that are as distantly related as plants, animals and fungi are related to each other

Lesson Two

I. Chemical Foundations of Life

• Describe the structure of an atom. • Explain why radioisotopes are important to biologists. • Describe how the configuration of electrons influences the chemical behavior of an atom. • Distinguish between covalent, ionic and hydrogen bonds

II. Water and pH

• List four ways that water contributes to the fitness of the environment • Explain how water's expansion upon freezing affects both aquatic and terrestrial ecosystems. • Describe the basis for the pH scale. • Tell how an acid differs from a base. • What is the cause and environmental consequence of acid rain?

III. Properties of Organic Compounds

• List the four major classes of macromolecules or biomolecules. • Describe how large carbohydrates, lipids, proteins and nucleic acids are broken down into smaller units. • Explain how smaller units are put together into larger ones. • Describe at least three specific functions of: Carbohydrates, lipids and proteins • Describe the molecular structure and importance of DNA and RNA. • Explain why fats, phospholipids and steroids are important to living systems. • Identify a peptide bond and explain how it is formed. • Define the primary, secondary (two forms), tertiary, and quaternary structure of a protein. • List the major components of a nucleotide. • Describe the three-dimensional structure of DNA.

Lesson 2 AYLs 1. Start at the level of amino acid and build a protein. Explain the four levels of structural organization and at least three examples of how proteins are used in the body.

2. Start at the level of the monosaccharide. Explain how dehydration reactions form disaccharides and polysaccharides. Describe, with specific examples, at least three uses of carbohydrates in living systems.

Monosaccharide is the smallest kind of sugar molecule, monosaccharides are building blocks for complex sugars and polysaccharides. Cells construct a disaccharide from two monosaccharides by dehydration reaction, and polysaccharides are polymers (large molecules joined in a chain) of monosaccharides linked together by dehydration reactions. Dehydration reaction is a chemical process in which a polymer is formed as monomers are linked by the removal of water molecules. 1) Immediate Energy~ food intake, cellular respiration produces ATP 2) Stored Energy ~ in the form of fat 3) Cell wall structure (plant)

3. Explain the chemistry behind the physical consistency of fats at room temperature. Explain what happens to the chemical and physical nature of a vegetable oil that has been hydrogenated to make margarine. How might hydrogenation of vegetable oil affect one’s health?

4. How does electron configuration influence the chemical behavior of an atom? Give two or three examples supporting your answer.

The most important consideration is valence (outer shell) electrons. All atoms want a full outer shell as with the noble gases. To achieve this, they will react in order to lose, gain or share electrons.

The alkali metals all have one valence electron and wish to lose this to obtain a noble gas electron configuration. The further that electron is from the nucleus, the easier it is to lose due to sheer distance and shielding of inner electron shells. Therefore, the further down the periodic table you get, the more reactive they are. The Brainiac video of this is well worth a look: http://www.youtube.com/watch?v=m55kgyApY…

With the halogens (fluorine, chlorine etc, group 7), they need to gain one electron to achieve a stable noble gas configuration. The less shieding of other electron shells there is, the easier it is to attract that extra electron in a reaction. This makes the halogens more reactive the higher they are in the periodic table.

When metals and non-metals react together, you often get complete transfer of electrons from the metal to the non-metal. The ions formed are held together by the attraction of the opposing charges. This is ionic bonding.

Metals generally lose up to 3 electron; non-metals can gain up to three. This leaves carbon with 4 valence electrons. It, and many other atoms find it more convenient to share electrons. So in the case of methane, CH4, each of carbon's four valence electrons will be shared with a hydrogen atom. Each hydrogen atom brings an electron, which it shares with carbon. Between them, there are 8 electrons. Each hydrogen has 2, giving it the same configuration as helium; carbon has 8, mimicking neon. This is the basis of covalent bonding.

When chemical reactions happen, they are generally rearranging the atoms to make the electron configurations as close as possible to the stable noble gases.

5. How is a hydrogen bond formed? How is it different from an ionic or a covalent bond? What special properties do hydrogen bonds give substances? Give an example of a substance that undergoes hydrogen bonding, and explain the unique properties this substance has.

Short Answer: a partially positive hydrogen atom gets attracted to a partially negatively charged atom. _______________________ Take water for example. There is an Oxygen atom (which pulls electrons towards it-- making it partially negative) There are also two hydrogen atoms. The (negatively charged) electron on each H atom is being pulled towards the O atom, making the Hydrogen partially positive.

Now, when two water molecules come together, the partially positively charged H's on one water molecule are attracted to the partially negatively charged O's on the other molecule. This attraction between oppositely charged atoms on different molecules creates a 'hydrogen bond'

6. Why is water necessary for all life on this planet? In terms of the properties of water, how does water benefit the environment? Give two or three examples supporting your answer.

Lesson Three

I. The Cell Theory and modern microscopy

• Describe the major kinds of microscopes and explain their main use. • Describe the use of the student light microscope (from the lab) • Summarize the work of:

* Van Leeuwenhoek * Robert Hooke

• State the three parts of the Cell Theory. • Tell why the Cell Theory, like the Theory of Evolution, is a "unifying" theory of life. • Explain why the Cell Theory is a theory and not a hypothesis.

II. Why Are Cells So Small?

• Describe how the relationship between the surface area of a cell and its volume changes as the cell increases in size. • Explain two reasons why smaller cells are biologically more efficient than larger cells. • Describe two adaptations that some larger cells have that essentially, solves the surface area to volume problem.

III. Origin of Eukaryotic Cells • Name the researcher credited with proposing the Endosymbiont Theory. • Describe two hypotheses to account for the origin of membrane-enclosed organelles within eukaryotic cells. • Explain the possible origin of mitochondria and chloroplasts in eukaryotic cells. • Name two characteristics that prokaryotic and eukaryotic cells share, and name two major differences between these two types of cells.

IV. Inside The Living Cell (energy converting organelles)

• Describe the function of chloroplasts • Describe the function of mitochondria • Explain, for each energy converting organelle of the cell, whether it would be found in: o autotrophic cells (photosynthetic) o heterotrophic cells (capture food) o both autotrophic and heterotrophic cells

V. Inside the Living Cell (Cytoskeleton, Locomotor, Appendages, Surfaces, and Junctions)

• Describe the function of the cytoskeleton. • Distinguish between microfilaments and microtubules. • Compare and contrast locomotor appendages • Describe the structure and function of cell walls. • Describe the structure and function of cell junctions. • Explain, for each of these components of the cell, whether it would be found in: o Autotrophic cells o Heterotrophic cells o Autotrophic and heterotrophic cells

Lesson 3 AYLs

1. Describe four organelles or structures that all eukaryotic cells have in common. In addition, describe two eukaryotic cell features that would be found only in autotrophic cells.

2. Describe the Endosymbiont Theory of the origin of eukaryotic cells. How does this theory differ from the idea that eukaryotic organelles arose from pinching off inner cell membrane pieces?

3. Discuss the relationship between the size of a cell and its internal volume. In describing why not all cells are big, explain what happens as cells start to grow bigger and how some larger cells solve this surface area to volume problem.

4. What are the parts of the Cell Theory? Which scientists contributed ideas to the Cell Theory? Describe the work of at least two scientists and how that research eventually led to the Cell Theory. Why is the Cell Theory an important tenet in biology?

5. Compare and contrast prokaryotic and eukaryotic cells. What are the similarities and differences between these two types of cells? Give two examples of each type of cell.

6. What are the different organelles associated with the endomembrane system? What is the function of each of the organelles? How do they work together to maintain an entire cell?

7. Compare and contrast mitochondria and chloroplasts. What are the similarities and differences between these two types of organelles? What is the significance of their similarities?

Lesson Four

I. The Structure of Membranes

• Describe the function of the cell membrane. • Sketch the structure of the cell membrane and label appropriate parts. • Describe the fluid properties of the cell membrane. • Define the term "phospholipid bilayer," hydrophobic, and hydrophilic. • Name and describe four kinds of membrane proteins and tell what they do.

II. Passage of Materials across Membranes

• Define the term "diffusion". Explain what causes diffusion and why it is a spontaneous event. • Distinguish between passive transport and active transport. • Explain what is meant by a concentration gradient and why molecules passively move down concentration gradients. • Define the term "osmosis" and be able to predict the direction of water movement based upon differences in solute concentration. • Define the terms: isotonic, hypotonic and hypertonic • Describe how living cells regulate water balance. • Sketch and describe the concept of facilitated diffusion. • Explain how active transport differs from diffusion. • Given a diagram of a cell with differing solute/water concentrations on each side of the membrane. Tell whether the cell itself is isotonic, hypotonic or hypertonic. • Distinguish between exocytosis and endocytosis. • Describe an amoeba feeding by phagocytosis.

Lesson 4 AYLs

1. Describe the structure of the cell membrane. Why is this structure referred to as a fluid mosaic model?

2. Explain what would happen to a freshwater unicellular organism if it was suddenly released into a saltwater environment. Use the terms isotonic, hypotonic and hypertonic in your answer. What would happen if a marine organism were placed in freshwater?

3. Distinguish between the following sets of terms: a. diffusion and osmosis b. endocytosis and exocytosis c. active transport and passive transport 4. How can substances move across a membrane against a concentration gradient? What are the processes that can accomplish this movement? Give an example of when this might need to take place.

5. How can large molecules or substances be moved into or out of the membrane-bound cell? Give at least one example of this type of transport.

Lesson Five

I. About Energy

• State the first law of thermodynamics. • State the second law of thermodynamics. • Define the terms: energy, metabolism, entropy. • Explain why we, as organized individual organisms, do not violate the second law of thermodynamics. • Distinguish between potential and kinetic energy.

II. How Is Work Done In The Cell?

• Describe the structure of ATP. • Explain how ATP functions in the cell. • Define the term "phosphorylation." • Diagram and describe the ATP - ADP cycle.

III. Enzyme Structure and Function

• Define the term "activation energy." • Describe the function of enzymes in biological systems. • Diagram and explain the induced fit model of enzyme function. • Describe the nature of an "active site." • Diagram and describe the effect of each of the following conditions on enzyme action: • Effect of temperature • Effect of pH • Feedback inhibition as a control of metabolic pathways • Function and value of coenzymes

Lesson 5 AYLs

1. State the first and second laws of thermodynamics and explain why you, as an individual human, do not violate the second law leading to entropy.

2. Describe the structure of ATP. Also, describe the ATP-ADP cycle and explain where the energy comes from to phosphorylate ADP to make more ATP, and what the energy is used for when ATP is broken down.

3. Describe the induced fit model of enzyme action. Also, describe at least four factors that modify the action of enzymes.

4. What is the difference between exergonic and endergonic reactions? Give an example of each. What is the significance of each type of reaction?

5. What is the role of enzymes in biological systems? What is their importance? Give two or three examples of important enzymes and how they are used in the human body.

6. What might happen to a biological system if a key enzyme was destroyed? Give an example of a disease or disorder that results in defective enzyme production, and describe how it affects the person with the disease.

Lesson Six

I. Introduction to Cellular Respiration

• Distinguish between breathing and respiration. • Sketch and label the structure of a mitochondrion. • Describe the three basic events of respiration: o Glycolysis o Krebs cycle o Electron transport phosphorylation • How many ATP molecules are made from one molecule of glucose? • Identify (name) and explain the function of NAD+ and FAD.

II. Glycolysis

• State the beginning molecule in glycolysis and the ending molecule. • How many ATP molecules are generated by glycolysis? What is the net gain? • Define the term "substrate-level" phosphorylation. • Name and tell the function of NAD+. • Niacin is the vitamin needed to make NAD+. • Explain where in the cell the events of glycolysis take place.

III. The Krebs Cycle

• Explain why the Krebs cycle is, in fact, described as a cyclic event. Tell how many NADH, FADH2, and ATP molecules are generated in the Krebs cycle for each molecule of glucose. • Name the 2C, the 6C. the 5C, and the 4C compounds in the Krebs cycle. • What is the name and function of FAD? • The vitamin needed to make FAD is riboflavin - that was too easy.

IV. Oxidative Phosphorylation and Chemiosmosis

• Explain how the structure of the membrane of the cristae is related to its function in electron transport phosphorylation. • Describe the process of electron transport. Where do the electrons come from, and what does the energy go to do? • Where do the oxygen and hydrogens, which finally form molecules of water, come from? • List the other organic molecules that can be used as fuel, and explain the amount of relative energy that can be obtained from each. • Distinguish between aerobic and anaerobic respiration. • Define the term lactic acid and explain the conditions in which lactic acid would be produced in your cells. • Explain how ATP is made by chemiosmosis?. • How much ATP is made by electron transport phosphorylation?

Lesson 6 AYLs

1. What is respiration? Summarize the major events of glycolysis, the Krebs cycle, and oxidative phosphorylation. As you describe each event explain where it occurs in the cell and how much ATP is generated at each step.

2. Distinguish between aerobic and anaerobic respiration. What kinds of organisms carry out each form of respiration? Describe the end products of each pattern.

3. Distinguish between substrate-level phosphorylation and oxidative phosphorylation. Where in the general sequence of respiration chemistry does each occur?

4. Describe the difference between breathing and cellular respiration. Why is it for medical professionals to understand the difference?

5. What kinds of organic molecules can be used by the cell to supply energy? Which kind of molecule is more effective at supplying energy than others? Give specific examples.

6. How does the structure of the mitochondrion allow cellular respiration to take place? Discuss the structure of this organelle and explain the steps of cellular respiration that occur within each part.

Lesson Seven

I. Chromosomes, The Cell Cycle, and Mitosis

• Distinguish between the final chromosome numbers in mitosis vs. meiosis. • Tell the difference between somatic cells and germ cells. • Describe the structure of a chromosome. • Sketch and define the term "sister chromatids." Label the "centromere." • Define the terms "diploid" and "homologous chromosomes." • Describe the cell cycle and explain the approximate percentage of time the cell is in each stage. • Define the terms: interphase, prophase, metaphase, anaphase, telophase • Name and sketch each stage of mitosis assuming the starting chromosome number of four.

II. Meiosis

• List the phases of meiosis I and meiosis II and describe what is happening in each stage. • Explain the difference between somatic cells and germ cells. • Define the terms diploid and homologous chromosomes • Recognize the phases of meiosis from diagrams • Describe the process of tetrad formation and crossing over. • Tell how the independent movements of homologous chromosomes and crossing over lead to diversity in eggs and sperm. • Explain how random fertilization further ensures diversity in offspring. • Distinguish between the events of oogenesis and spermatogenesis. How is it that only one egg, but four sperm result from meiosis of their respective parent cells?

Lesson 7 AYLs 1. Describe the similarities and differences between the two types of nuclear division mechanisms that occur in eukaryotes (mitosis and meiosis). Use a chromosome number of 46 in your explanation.

2. Discuss how independent assortment, crossing over, and random fertilization lead to diversity in eukaryotic offspring.

3. Explain the difference in time that occurs when a cell is living its normal life compared to when it is dividing. Why does this difference occur? Describe the things a cell must accomplish during cell division vs. during "normal life."

4. Why is it necessary for mitosis to result in identical daughter cells? What happens when the daughter cells are not identical to the parent cell?

5. What is cytokinesis? Compare and contrast cytokinesis in an animal cell and in a plant cell.

6. Why is it necessary for chromosome number to be halved during meiosis? What would happen to offspring if this reduction in chromosome number didn't occur?