SC 135 - Second Exam 1997

On the line to the left, place the letter of the choice that best answers the question.

A. NOTE: "e" answers are never the correct answer. Five Points Each.

1. In which bond are electrons shared?

__________    a. Hydrogen                 b. Ionic                c. Covalent 
                        d. Osmotic                e. Handcuffs for two wired to a battery

2. Which is an example of spontaneous generation?

__________   a. Baby snakes hatching from eggs
                            b. Amebas dividing
                            c. A scar forming where a wound was
                            d. Snails forming from rocks on a stream bottom
                            e. I just know that my paycheck does something like the opposite...

3. Which chemical process is essential in the digestion (breakdown) of food?

__________    a. Hydrolysis             b. Dehydration synthesis            c. Osmosis 
                        d. Ionic bonding                     e. The creation of special sauce

4. When liver cells process glucose, glucose moves from a lower blood concentration 
                                into the higher-concentration cells. This is

__________    a. Osmotic pressure             b. Active transport            c. Secretion 
                        d. Passive transport       e. Inconvenient when you're trying for a "sugar high..."

5. Which of the following is not a polymer?

__________   a. Protein                 b. Nucleic acid                 c. Starch
                            d. Sugar                     e. Eenimer, meenimer, mynimer, mo...

6. An atom is most stable as an ion with a negative one ( ^- ) charge. How many electrons  
                                should it have in its outer orbital?

__________   a. 1             b. 8             c. 7             d. 3            e. Oh, that's what it meant.....

7. Which is best described as a phospholipid bilayer?

__________    a. DNA                 b. Cell membrane                c. Cell wall 
                        d. Ribosome                                e. A Twinkie

8. Steroid hormones belong to which class of organic molecule?

__________   a. Lipids                 b. Proteins                 c. Carbohydrates
                            d. Nucleic Acids                     e. Pumped-up molecules

9. The pH of digestive juices in the intestine is between 7.5 and 8.5. Compared with a 
                            neutral pH, the concentration of H⁺ ions should be

__________    a. Higher                            b. Lower                        c. Equal 
                        d. There's no way to tell        e. I saw this in the book - guess I should have figured it out...

10. The extremely salty water of the Dead Sea is what sort of solution for almost any 
                                organism that would try to live there?

__________      a. Isotonic                     b. Hypertonic                     d. Hypotonic
                                d. Cytotonic                                     e. Gin and tonic

11. Polydehydrogenase would belong to which class of organic molecule?

__________   a. Oils                         b. Enzymes                         c. Starches
                            d. Nucleic Acids          e. No, you're not supposed to recognize the word.

12. When iron (Fe) rusts, it starts as Fe⁺² and becomes Fe⁺³. Rusting is a(n)

__________    a. Enzyme reaction             b. Reduction reaction            c. Oxidation reaction 
                        d. Hydrolysis reaction          e. Process I think my brain cells are doing right now

13. Which cell element is most involved in cell movement?

__________    a. Microtubules                     b. Nucleolus                    c. Vacuoles 
                        d. Microfilaments                            e. Incredibly tiny moving vans

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. Mitochondrial DNA does not "mix & match" every generation. Why not?

2. Lipid molecules are constructed from two basic parts. What are these molecule subunits?

3. What are plasmids, and where exactly are they found?

4. What happens during phagocytosis?

5. What exactly makes a molecule polar? (Not necessarily bipolar!)

6. Explain what a codon is.

7. Cells are rarely above a certain size. What bad thing happens as a cell increases in size?

8. By the newest definition, what features must a molecule have to be considered organic?

9. For what two different, major reasons do plants produce glucose?

10. RNA and DNA molecules are built differently. Give two differences in the way the molecules are put together.

11. The fluid mosaic model describes a cell membrane. Explain:

    In what way is the membrane fluid?

    In what way is the membrane a mosaic?

12. Some people think that the cell damage of aging is produced by oxygen radicals.

    What exactly is a radical?

    Why are they so damaging?

13. Give the common names of the two basic forms of carbohydrates:

Simple:

Complex:

14. What purpose is served by microvilli?

15. What is a hydration shell?

16. Fill in the blanks: _______________ molecules in a nucleus are coiled up into

a material called _______________ ; during cell  division  this  material  is  packed

into  individual pieces called _______________ .

17. What are two basic principles of the cell theory?

18. Name two features of both mitochondria and chloroplasts that support the endosymbiont theory.

19. Which property of water is it when water is "soaked up" by the cellulose of a paper towel?

Answer any five of the following questions for 13 Points Each.
Note: if you answer more than five, only the first five will be corrected.

1. Name and define three of the four structural levels of proteins.

2. Give a function of any three of the four organelles listed below:

3. Fill in the chart below for cell structures you might see with an electron microscope.

4. Give the following cell chemical reactions: (include all molecules and energy types)

Photosynthesis:                                                              ------->

5. For cilia and flagella, list three pairs of differences.

6. The atoms in the following molecule are either Carbon (C), Hydrogen (H), Nitrogen (N) or Oxygen (O). Fill in the boxes with the appropriate atom.

7. For proteins and lipids molecules, give three distinctly different uses (functions - don't just list types, tell what they do) for each in a cell.

8. Name three types of adaptations living things use against osmotic pressure. For each, explain how that adaptation keeps osmotic pressure from harming the organisms.

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

Why is Earth's atmosphere mostly (almost 3/4) nitrogen? Five Points.

Local lakes "turn over" in the fall and spring. What exactly causes this? Five Points.

Antibody molecules have two functional ends. What, for four points each, does each end do?

Skeletal muscle cells have many nuclei. Contrary to what the book claims, what's the real reason for this? Four Points.

What advantage do organisms get from having multiple chromosomes, and what possible disadvantage can come from multiple chromosomes? Four Points each.

Cilia move new embryos down the fallopian tubes to the uterus. Smokers are more likely to have an embryo stall in the tubes, producing a dangerous tubal pregnancy. Why, exactly? Four Points.

People requiring intravenous fluids are given a saline (salt) solution rather than pure water. Why? Five Points.