SC 135 - Third Exam 1998

On the line to the left, place the letter of the choice that best answers the question.
NOTE: "e" answers are never the correct answer. Six Points Each.

1. In living systems, activation energy is reduced by

__________    a. Absorbing it with special kinetic energy
                              b. Expending it with special potential energy
                              c. Enzymes
                              d. Chlorophyll
                              e. Rather far-reaching payroll taxes

2. The active site of an enzyme

__________    a. Binds to the product(s) of a reaction
                              b. Binds to the substrate(s) of a reaction
                              c. Absorbs certain frequencies of light energy
                              d. Binds only to particular nitrogenous bases
                              e. Is more interesting than the lazy good-for-nothing site

3. Because of Barr bodies, human females

__________    a. Only use 1 X chromosome in each cell
                              b. Only produce 1 egg cell in a typical month
                              c. Only produce 1 egg cell from 1 starting cell
                              d. Can't use their hidden Y chromosome
                              e. Can always give someone a quick whack upside the head

4. Which statement is true?

__________    a. Heterotrophs are the most species and have the most biomass
                              b. Autotrophs are the most species and have the most biomass
                              c. Heterotrophs are the most species, autotrophs have the most biomass
                              d. Autotrophs are the most species, heterotrophs have the most biomass
                              e. A whole semester and it's still like an unknown foreign language...

5. The big advantage of aerobic respiration over anaerobic respiration can be connected 
                                            mostly to the fact that

__________    a. Aerobic produces much more ATP
                              b. Aerobic uses oxygen and carbon dioxide
                              c. Aerobic makes use of sunlight energy
                              d. Only aerobic uses glucose
                              e. Aerobic gets much better publicity

6. In alternations of generations, what alternates?

__________    a. Male forms and female forms
                              b. Mobile forms and nonmobile forms
                              c. Endergonic and exergonic processes
                              d. Sexual reproduction and asexual reproduction
                              e. Well, generations, obviously

7. If offspring come from a single parent organism,

__________    a. They must be asexually produced
                              b. They must be sexually produced
                              c. They could be asexually or sexually produced
                              d. All of the above
                              e. They'll soon be on a sitcom, or Jerry Springer

8. One thing that occurs during decomposition is that

__________    a. Many products of breakdown are fed into respiratory pathways
                              b. Most of the energy in the molecules is recycled
                              c. Molecules from the source organisms are used without changing them
                              d. Only anaerobic respiration is done
                              e. Lots of nasty stuff goes on

9. A histone would be involved in

__________    a. Pulling chromatids apart                      b. Blocking an active site
                              c. Wrapping up DNA                             d. Capturing light energy
                              e. The beginning of an argument: "I don't think I like histone..."

10. Which is true about ATP -----> ADP + Phosphate ?

__________    a. It's the endergonic pair of most biological coupled reactions
                              b. It's the exergonic pair of most biological coupled reactions
                              c. They are the substrates of most biological coupled reactions
                              d. They are the products of most biological coupled reactions
                              e. It's not likely to be misspelled

11. A polar body is used for

__________    a. Discarding of unusable chromosomes
                              b. Holding chromatids together
                              c. Aerobic respiration
                              d. Non-chlorophyll photosynthesis
                              e. Selling snowmobiles in TV ads

SHORT ANSWER. 

Answer any ten of the following questions for 7 Points Each.
Note: if you answer more than ten, only the first ten will be corrected.

1. Both stages of photosynthesis are endergonic reactions. The loss of what *two sources* stops them?

2. CLARIFY.Other than in the names and functions, how do the products differ between sperm production and egg cell production? Be specific.

3. Oxygen debt builds up in ____________________ cells, where in the absence of available

oxygen, ___________________ builds up.

4. What is a centromere?

5. What is meant by the expression, "an enzyme's optimal pH range?"

6. Name the cycle reactions involved in:

Aerobic Respiration ______________ Photosynthesis ______________

7. What two factors are most involved in producing bioaccumulation of pollutants?

8. What, technically, is a mutation?

9. Why would a plant grow very poorly under a green light?

10. What is a karyotype?

11. Put these in the proper order for a simple food chain: Decomposers, Primary Consumers, Producers, Secondary Consumers.

________________----> ________________---->________________----> _______________

12. For cell interphase...

13. Name two commercial products whose production relies on different types of anaerobic respiration.

14. There is one huge difference between meiosis and mitosis. Why, ultimately, do organisms need this difference? (We're not just looking for the different products here, but the reason they are made this way.)

15. Briefly explain the first law of thermodynamics (just the name isn't enough).

17. What happens during end-product feedback inhibition?

18. What is the chemical function of vitamins? What type of molecules are they?

LONG ANSWER. 

Answer any four of the following questions for 16 Points Each.
Note: if you answer more than five, only the first five will be corrected.

1. Name each of the four phases of mitosis (remember, the fifth is between), and for each phase describe one thing that occurs only during that phase.

2. Fill in the blanks for light in the visible spectrum.

5. Fill in for the two stages of Meiosis.

3. Briefly explain, step-by-step, the process of aerobic respiration. Be sure to include anaerobic (glycolysis), the particular cycle involved, the electron transfer chain, and the substrates and products involved. You do not need to attach specific numbers to substrates or products.

4. Explain, step-by-step, how a gene is used to produce a protein. Make sure to cover the roles of DNA, amino acids, the two types of RNA, codons, the nucleus, and ribosomes.

6. Fill in the blanks for the two reactions of photosynthesis.

7. Describe three ways that an enzyme can be chemically "turned off."

8. For the one side of the DNA molecule shown below, fill in:

                                         ___________________________________________________
A) Starting DNA, one side:  C   G   A   C   G   T   T   A   G   A   T   C   A   T   C   C   A   G

B) Other DNA side: ___________________________________________________

C) RNA made from A) ___________________________________________________

Link to Answer Key

BONUS QUESTIONS. 

Answer as many as you are able. Wrong answers will not result in points being lost from the main exam.

What is the usual consequence if fertilization involves either a sperm or egg cell with an extra chromosome? Five points.

What is meant by XX - X0? Five Points.

What two areas of human health may be hugely affected by telomere research? Eight Points.

Proteins can be denatured by high temperatures. Why? Five Points.

Proteins can be denatured by extremes in pH. Why? Five Points.

What, on a molecular level, would be the effect of a successful fever? Five Points.

Ultraviolet light is a cause of skin cancer. What exactly does it do to cells to produce cancer? Five Points.

What are two different circumstances when carotenoids are clearly visible? Four Points Each.

Review question: for three points each, plus one for each in the right order, what are the steps of the Scientific Method?