Biology 111

Final Exam Review/Study Questions KEY

Multiple choice. Circle all correct answers.

1. At which level of protein structure are interactions between R groups important?

a. primary

b. secondary

c. tertiary

d. quaternary

 

2. Large amounts of rough ER are present in a cell that ...

a. synthesizes proteins for export

b. synthesizes proteins for intracellular use

c. detoxifies poisons

d. is cancerous

 

3. You move an onion epidermal peel from distilled water to a 5% salt (NaCl) solution. Assume the onion cell membrane has no transport proteins for Na+ or Cl-. After a few minutes ...

a. the amount of salt in the cytoplasm of the onion cells will not have changed.

b. water will no longer pass into or out of the cytoplasm of the onion cells.

c. the salt levels will be at equilibrium inside and outside the cytoplasm of the onion cells.

d. the turgor pressure inside the cells will have increased

 

4. Which of the following processes below generate(s) ATP? Put an asterisk by the process that generates the most ATP.

a. glycolysis

b. Krebs cycle

c. electron transport chain of cellular respiration *

d. fermentation

 

5. Muscle cells that are deprived of O₂ convert pyruvate to ___A____ to obtain ___B____.

A	B
a. lactic acid	a. ATP
b. ethanol	b. NADH
c. CO2	c. NAD+
d. glucose	d. ADP

 

6. At the end of photophosphorylation, the energy from light resides in ...

a. NADPH

b. glucose

c. O₂

d. ATP

 

7. Which of the following compounds is an electron carrier?

a. ATP

b. NADH

c. NADPH

d. FADH₂

 

8. Which of the following conditions might cause an isolated chloroplasts to fluoresce under bright light?

a. excess O₂

b. insufficient O₂

c. insufficient CO₂

d. insufficient NADP⁺

 

9. You've injected a basic (high pH) solution into the interior of a thylakoid of a chloroplast without otherwise disturbing the chloroplast at all. What effect will this manipulation have on ATP synthesis?

a. ATP production will increase

b. ATP production will decrease

c. ATP production will remain unchanged

d. Not enough information is given to tell.

 

10. Sister chromatids have which of the following characteristics in common?

a. the same genes

b. the same alleles

c. the same length

d. the same daughter cell destination in anaphase I of meiosis

 

11. Which of the following conditions stimulate the EXPORT of K⁺ out of guard cells?

a. water deficiency

b. high internal CO₂

c. high light

d. high internal O₂

 

12. You cut a plant stem from a leafy branch high on a tree on a sunny day and notice a small droplet exuding from both cut ends. Where does this liquid come from?

a. xylem

b. phloem

c. epidermis

d. ground tissue

 

13. Phloem transport of sucrose can be described as going from "source to sink." Which of the following would normally function as a sink?

a. growing fruit

b. growing root

c. mature leaf

d. shoot tip

 

14. In the evaporation-cohesion-tension model of xylem transport, what generates the tension?

a. osmotic uptake of water across the endodermis

b. hydrogen bonds between water molecules

c. active transport of ions into the endodermis

d. evaporation of water from leaves

 

15. At the start of translation, ____A_____ binds to the _____B______ .

A	B
a. a transcription factor	a. 3' poly A tail
b. RNA polymerase	b. promotor
c. the small ribosomal subunit	c. 5' cap
d. the large ribosomal subunit	d. large ribosomal subunit

 

16. After police collected a drop of blood sample at the scene of the crime, they might use which of the following techniques in obtaining a suspect's genetic fingerprint?

a. gel electrophoresis

b. restriction enzyme digestion

c. PCR

d. cloning

 

17. What are the four types of macromolecules? Which class is different in structure from the rest? How is it different?

Proteins, Carbohydrates, Nucleic acids, and Lipids. Lipids are different in that they are not polymers made up of repeating monomeric units. They are also different in that they are all hydrophobic whereas all the other macromolecule classes are hydrophilic.

18. Refer to the reaction below to answer parts a and b.

a. Is the compound to the left acting as an acid or a base? Acid

b. Does this reaction lead to an increase or a decrease in pH? Decrease in pH

 

How (IN, OUT, or WON'T MOVE) and by what process (ACTIVE TRANSPORT, SIMPLE DIFFUSION, FACILITATED DIFFUSION) will the molecules listed in the table below cross this membrane? Note that the direction of movement is given to you for glucose and H⁺.

Molecule	Net Movement (IN, OUT, WON'T MOVE)	Process
Na+	WON'T MOVE	NONE
Glucose	IN	ACTIVE TRANSPORT
H+	IN	FACILITATED DIFFUSION
O2	OUT	SIMPLE DIFFUSION

20. Refer to the reaction below to answer parts a through c.

a. This reaction represents ...

oxidation

reduction

(circle neither, one, or both)

b. X⁺ is undergoing _reduction_ to become XH.

c. YH₂ is undergoing ____oxidation____ to become Y.

 

21. Consider the reaction: glucose -----> CO₂.

a. Diagram this reaction on the axes below, labeling the axes, DG, and E_A.

b. Is this reaction exergonic or endergonic ? (Circle one)

c. Is DG for this reaction positive or negative ? (Circle one)

 

22. Which of the transport mechanisms to the right are directly involved in the processes listed to the left? Place the correct letter for the transport mechanism in the blank to the left of the process. Each blank has only one letter; letters may be used more than once or not at all.

__C___ Sugar entering phloem at "source"	A. Diffusion B. Facilitated diffusion
__D___ Water entering phloem at "source"	C. Active transport D. Osmosis
__A___ Water exiting leaves through stomates	E. Endocytosis F. Exocytosis
__C___ K+ moving into guard cells
__A___ CO2 entering leaves through stomates
__A___ O2 exiting leaves through stomates

23. Use the diagram of the cell below to answer parts a through c.

a. What are the names of the structures indicated in the diagram? Fill in the correct structure names in the blanks to the right of their associated letters.

A = Golgi apparatus, B = ribosome, C = mitochondrion,
D = smooth ER, E = nucleus

b. Is this cell a prokaryote, animal, or plant cell? How do you know?

This is an animal cell. It has membrane-bound organelles (therefore not a prokaryote), and it has no cell wall or central vacuole (therefore not a plant cell).

c. Based on its contents, what is the general function of this cell? Explain your answer.

This cell probably has a secretory function. The large vesicles showing exocytosis and the reasonably large amount of rough ER suggest this.

24. In each blank, place the letter(s) of the cellular compartment(s) in which the process takes place.

___F___ Glycolysis	A. Mitochondrial matrix
__G, H__ Electron transport chain	B. Mitochondrial intermembrane space
___A___ Krebs cycle	C. Chloroplast stroma
___C___ Calvin cycle	D. Thylakoid interior
__B, D__ H+ build-up	E. Nucleus
___E___ Transcription	F. Cytosol
___F___ Translation	G. Thylakoid membrane
___G___ Light reactions	H. Mitochondrial inner membrane

25. In which of the processes are the following components directly used? Place the correct letter for the component in the blank to the left of its associated process. Each blank has one or more letters; letters may be used more than once or not at all.

A. DNA polymerase	D. DNA nucleotides	G. ribosomes
B. RNA polymerase/primase	E. RNA nucleotides	H. primers
C. transcription factors	F. mRNA	I. tRNA

____A, B, D, E_____ DNA replication

_____B, E____________ Transcription

_____F, G, I___________ Translation

____A, D, H___________ PCR

 

26. In the following DNA sequence,

a. draw a box around the part of the template strand that codes for amino acids in the final polypeptide

b.write in the polarities of each end of both strands.

__3'__ T A T C G G A T A A G T C T C G T G T A T A T A __5'__
__5'__ A T A G C C T A T T C A G A G C A C A T A T A T __3'__

 

27. You've decided to examine the effect of light intensity on photosynthetic rate. Your experimental design involves placing a plant in an enclosed chamber, exposing it to high intensity light, and measuring how the oxygen concentration in the chamber changes over time. You then repeat the experiment with the same plant, this time exposing the plant to low intensity light. Finally, you conduct the experiment one last time, this time with the plant in complete darkness. Below are the results of your experiment.

a. What happened to oxygen concentration when the plant was exposed to high intensity light? What processes are occurring to cause this effect? Explain your answer.

 Oxygen concentration increased when the plant was exposed to high intensity light because non-cyclic photophosphorylation caused PSII to pull electrons from water, resulting in molecular O₂ as a waste product. Under high light intensity, photosynthesis produces oxygen faster than respiration uses it. O₂ builds up faster than it is used, raising the net concentration.

b. What happened to oxygen concentration when the plant was exposed to low intensity light? What processes are occurring to cause this effect? Explain your answer.

 At low intensity light, O2 production in photosynthesis and O2 use in respiration are equal and O2 concentration stays constant over time.

c. What happened to oxygen concentration when the plant was kept in darkness? What processes are occurring to cause this effect? Explain your answer.

 In the dark, the generation of O2 in photosynthesis cannot continue. Respiration does continue to use O2, however, and the concentration of O2 decreases over time.

28. Answer the following questions on enzyme activity.

a. Enzymes are very specific in their catalytic functions, with each enzyme generally catalyzing only a single reaction. How is it that an enzyme in a mixture of possible substrates reacts only with its own substrate?

 Enzyme specificity comes from the nature of enzyme-substrate recognition. It is the 3-D fit of substrates into the active sites of their enzymes that allows specificity. An enzyme active site generally fits only its substrate.

b. Enzymes speed reactions by lowering the activation energy. How do they do that?

Enzymes speed reactions by lowering activation energy. They do this by stressing ("bending") the existing bonds in the substrate(s). All reactions require breaking existing bonds and forming new bonds. It is in the "bending" of old bonds when the substrate is "induced to fit" into the active site that lowers the energy required to break those old bonds. Stressed bonds are easier to break than bonds in their most stable form.

c. Given that enzymes make a reaction proceed faster, can they cause more of a product to be made than would be found at equilibrium without the enzyme? Why or why not?

Enzymes do not alter the equilibrium concentrations of reactants and products. Although they speed the reactions, they speed both the forward and reverse reactions.

d. Temperature and pH generally have drastic effects on enzyme activity. What do these environmental factors do to enzymes to alter their ability to catalyze their reactions?

Temperature and pH both can alter protein secondary, tertiary (and quaternary, if present) structure. Because the shape of the active site is fundamental to enzyme activity (see part a), any changes in protein structure are likely to alter the shape of the active site, and therefore, alter enzyme activity.

 

29. Skin color in your favorite Tyrannosaurus rex, Barney, is controlled by three alleles, two of which are codominant. The codominant red (C^R) and blue (C^B) alleles are both dominant to white (c). The famous purple Barney meets, woos, and marries Barnedette, who is red (I guess this makes Barney's third wife this semester. Nobody ever claimed that T. rex was a faithful husband!). After the proper period of time, Barnedette conceives and lays an egg, out of which hatches darling blue Baby Bop (oh no, more!) that they love dearly (I'm sure you know the song, "I love you, you love me ..."). You can safely assume that Barney is Bop's father (remember, this is children's television.)

a. What are the genotypes of each individual in our story?

Barney C^BC^R (purple)

Barnedette C^R i (red)

Baby Bop (blue)

b. Assuming Barney and Barnedette have a large family, what would be the expected (1) genotypes, (2) genotypic ratio, (3) phenotypes, and (4) phenotypic ratio of their offspring? Show your work, including a (5) Punnett square.

(F₁) genotypes and ratio: 1 C^BC^R : 1 C^Bi : 1 C^RC^R : 1C^Ri

(F₁) phenotypes and ratio: 1 purple : 1 blue : 2 red

 

Barney-->	CB	CR
Bernadette CR	CBCR	CRCR
i	CBi	CRi

 

30. Which of the following fingerprints probably belong to siblings? (Differences in thickness of the bands was introduced by the web--don't attach any significance to it!)

Of the banding patterns shown, 1 and 3 have the most bands in common, and are, therefore, are likely to be more closely related than the others. They must be the siblings. 

31. Below is a diagram of a cell undergoing a change. Use the diagram to answer the questions below.

a. What kind of a cell is the large round one shown by "a"? An egg cell

b. What kind of molecule is shown by "b"?

1. relay molecule

2. receptor protein

3. protein kinase

4. ligand-gated ion channel

c. What kind of molecule is shown by "c"?

1. relay molecule

2. receptor protein

3. protein kinase

4. ligand-gated ion channel

d. What are the structures shown by "d"? cortical granules

e. What is the function of the structures shown by "d"? slow block to polyspermy - they release solute ions that cause water to flow into the area between the vitelline layer and the egg, lifting the vitelline layer off the surface of the egg. They also release enzymes that harden the vitelline layer into a shell that prevents any further entry by sperm.

 32. Cancer occurs when normal genes undergo mutation. What is the usual function of these normal genes? These genes normally control the mitotic cell cycle in some way. When they sustain mutations, the proteins coded for by them can't do their normal control functions. When this lack of function results in uncontolled growth, we call that cancer.