BI 171- Second Exam 2006

BI 171 - Second Exam - 2006

Multiple Choice.

Place the letter of the choice that best answers the question on the line to the left.
Two Points Each. NOTE: "e" answers are never the correct answer.

Each question's number is linked to the relevant part of the online book, if possible (some questions relate to multiple sections).

_______ 1. The major component in all cell membranes is

a. Proteins b. Carbohydrates c. Lipids d. Water e. Membraney stuff

_______ 2. Which is true?

                    a. DNA contains genes, which contain codons
                    b. Genes contain both codons and DNA
                    c. Codons contain genes, which contain DNA
                    d. Genes and codons are separate things, both contain DNA
                    e. Feeling slightly dizzy now...

_______ 3. Chemical instability of an atom is connected to the number of

a. Electrons b. Protons c. Neutrons d. Hadrons e. Something-ons

_______ 4. Stereospecificity would be a major contributor to

                    a. Gene codes                       b. Steroid hormone movement through a membrane
                    c. Protein complexes             d. Adhesion of water
                                        e. Pimping a car

_______ 5. Chaperonins are directly involved in

                    a. Final protein conformation                     b. Carrying gene codes
                    c. Providing energy to processes                d. Stabilizing cell membranes
                            e. Molecular proms (and they wear really little corsages)

_______ 6. Which is true about epigenetic traits?

                    a. They only pass from parents to offspring
                    b. Eventually they become genetic traits
                    c. They follow patterns that Lamarck described
                    d. All of the above
                    e. Doesn’t "epi" mean that they’re hairy?

_______ 7. Water is most dense at which temperature, in degrees Celsius?

a. Zero b. Four c. Thirty-two d. One hundred e. Eleventy-seven

_______ 8. The term hydration shell is involved in the explanation for why

                    a. Water has a surface tension                             b. Ionic compounds dissolve in water
                    c. There’s no such thing as "pure" water              d. Water boils away slowly
                    e. There are too many terms in biology classes - really, "hydration shell"??

_______ 9. If the DNA sequence on one side is AACTGAGGC, the sequence on the other side
of the DNA is

a. AACTGAGGC b. AACUGAGGC c. CCAGTCTTA
d. TTGACTCCG e. GAG, GAG, GAG, GAG, AUG!

_______ 10. A jump from pH 6 to pH 5 generally means

                    a. A base ten times                                   b. A base one-fifth stronger
                    c. An acid ten times stronger                     d. An acid one-fifth stronger
                                                        e. It gets teensier

_______ 11. Hormones are mostly

a. Carbohydrates and lipids b. Lipids and proteins c. Proteins and carbohydrates
d. RNA e. An annoyance

_______ 12. The RNA World hypothesis picks RNA as a likely component of early systems because
it combines functions found in

                    a. Carbohydrates and lipids                     b. Lipids and proteins
                    c. Lipids and DNA                                 d. Proteins and DNA
                                        e. Because it's just so pretty!

_______ 13. If two molecules are identical except that one is saturated and the other is unsaturated,
the saturated one

a. Is dissolved b. Has more total bonds c. Has more single bonds
d. Has more carbons e. Shouldn’t be driving

_______ 14. Which element is fairly common in living systems?

a. Uranium b. Radon c. Glucose d. Phosphorus e. Surprise

_______ 15. Which is true of basic respiration?

                    a. Always involves oxygen                     b. Always involves carbohydrates
                    c. Always involves energy                     d. Always involves carbon dioxide
                                        e. It’s cheaper than the ultra-model respiration

_______ 16. In DNA processing

                    a. Translation is used to make RNA, transcription used to make protein
                    b. Transcription is used to make RNA, translation used to make protein
                    c. There is not adenine in the RNA
                    d. Every DNA nucleotide is used for 3 amino acids on the protein
                    e. There are tiny little office workers with little keyboards

_______ 17. The production of starches from sugars

                    a. Can’t be done directly                     b. Requires RNA as an intermediate|
                    c. Is a hydrolysis process                     d. Is a dehydration synthesis process
                    e. Doesn’t sound like much of a money-maker

_______ 18. When theorists first began to develop a theory of how Life began without using
supernatural explanations, they ran into difficulty because they decided
that the first step had to be the appearance of

a. Photosynthesis b. Animals c. Chemosynthesis
d. Respiration e. European people

Short Answer.

Pick NINE questions to answer in the spaces provided.
NOTE: if you answer MORE than nine, only the first nine will be corrected.
Four Points each. Partial credit is possible.

1. In the primordial soup hypothesis, what are two features of Life that had to be present right from the start, in the pre-Life systems?

2. In the primordial soup hypothesis, what are two features of Life that had to be present eventually, but would definitely not be present right from the start?

3. Give four basic functions that are carried out by proteins in living cells.


4. Ignore the specifics - label with the general terms that could be applied to any chemical reaction -
CO₂ + H₂O light > C₆H₁₂O₆ + O₂ --------------- --------------- ----------------- ---------------- -----------------
5. Give two molecules, from different classes of organic molecules, that have been used in classification to set up evolutionary connections.

6. Why does polarity exist in some molecules? Explain, don’t define!
7. For the Hardy-Weinberg rules to work, what are two features a population must have?

8. How many carbons in each? _____ Ethane _____ Methane _____ Propane
9. Briefly explain why the radical form of most atoms are chemically unstable.
*10.* What are two things present, today, that provide evidence that hydrothermal vents may have been where the earliest living things developed?

*11.* Plants produce two different types of starches with two different types of bonds. What is the main purpose of each type?

*12.* Of the three major approaches to alternation of generations, briefly explain the basic reason that two are used (what non-reproductive aspects of the life cycles exist?)

*13.* What are the two component parts of a typical lipid molecule?

*14.* Briefly explain the circumstances under which genetic drift happens. (Not looking for a full definition here!)
*15.* What is supposed to have happened, according to the theory of panspermia?
*16.* Briefly explain what leads to a founder effect.

Long Answer.

Select and answer completely any four of the following questions.
Note: if you answer more than four, only the first four will be corrected.
Seven Points Each. Partial credit is possible.

1. Using the numbers of bonds as a guide, fill in the symbols for either Carbon, Hydrogen, Nitrogen, or Oxygen.
This was boxes connected by bonds, anywhere from 1 to 4 bonds on each box. BONUS - Three Points - What specific type of molecule is this? ________________
2. For three different types of isolation, give the term and briefly describe how it works



3. Name and give a description of the four levels of protein structure.

4. 9.01218 Be Beryllium 4 Column 2	How many protons?	How many neutrons?
	How many electrons? (Radical form)	Typical ion form?
5. Name and describe the three basic bond types.



6. For four functional organic molecule groups, give the name, then show the arrangement of atoms in enough detail to demonstrate completely how each group works.




7. Put these in chronological order, according to the way current theories think they occurred - number from 1 (earliest) to 9 (latest).
Aerobic _____ Respiration	Molecular _____ Evolution	Photosynthesis _____
Protocells _____ (First Membranes)	Cambrian _____ Explosion	Eukaryotes _____
Life on _____ Land	Multicellular _____ Life	Primordial _____ Soup Forms

Link to Answer Key

BONUS QUESTIONS.

Answer as many or as few as you wish. You can't lose points on the rest of the exam by getting these wrong. Partial credit is possible.

Comparative biochemistry may use a Y chromosome. Give one advantage to using this, and one disadvantage. Three Points each.

For Two Points Each, up to four factors, what factors of existence on Land were major changes to the living things moving from water systems "up"?

What element, obvious from Hardy-Weinberg, was not recognized until very recently? Three Points.

Why might the Snowball Period have been the critical factor in the development of multicellular animal life? Three Points.

What were the prevalent type of animals when the largest known extinction event happened? Three Points.

When fossils become too old for Carbon dating, what in general is used then? Three Points

What feature of amino acids found in proteins turns out to be very difficult to explain? Three Points.

What molecule is turning out to have many, many more uses in living things than the few that were known until recently? Three Points.

BI 171

McDarby