SC 139 - Second Exam 2005


Links on Numbers go to relevant passages in the online textbook.

MULTIPLE CHOICE.

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

1. The concept of panspermia is connected to

_______         a. A type of sexual reproduction                b. A type of asexual reproduction
                      c. The beginnings of Life on Earth            d. A particular type of isolation
                                                e. A fairly dirty Greek myth

 

2. The vast majority of mutations have

_______         a. No or almost no effect                             b. A really bad effect
                      c. At least a partly good effect                     d. A really good effect
                                                        e. No nicknames

 

3. Even after true prokaryotes had evolved here, the Earth would have lacked

_______         a. Oceans         b. Rain         c. An ozone layer        d. Molecules
                                            e. Insurance salesmen

 

4. Genetic drift would be most obvious in descendent groups that are also

_______         a. Aerobic respirators                 b. Ecospecies             c. Greatly reduced in number
                      d. Asexual                                              e. On a genetic raft

 

5. Alleles are

_______         a. A primitive organism             b. Epigenetic            c. Colonial organisms
                      d. Variations in gene codes                        e. A very odd word

 

6. Which was an important clue in understanding the evolution of photosynthesis?

                      a. Fungi can use carbon dioxide
                      b. Hydrothermal vents glow
_______         c. Primordial soup had chlorophyll in it
                      d. DNA can absorb light
                      e. Finding someone who understood photosynthesis

 

7. Stromatolites are some of the best fossils of early

_______         a. Plants                 b. Animals                c. Fungi
                      d. Bacteria                    e. Stroma, before they got heavier

 

8. The materials that made up the primordial soup were figured out by analyzing

_______         a. Fossils                     b. Lava                     c. The Sun
                      d. Space dust                     e. Chickens and noodles

 

9.  The disadvantage of having a high chromosome number appears when

_______         a. Cells divide                 b. Environments change            c. Lethal genes appear
                      d. Oxygen is low                        e. You’re trying to look all humble

 

10.  Which can be autotrophs?

_______         a. Animals only                 b. Plants only             c. Bacteria and animals
                      d. Bacteria and plants                    e. Is that an award with a car on it?

 

11. There seems to be a limit on how big peacock tails can get - they can’t be so large that the
        males can’t fly away from predators. This means that

_______         a. Sexual selection is just as important as natural selection
                      b. Sexual selection is more important than natural selection
                      c. Natural selection is more important than sexual selection
                      d. None of these is indicated
                      e. Peacocks is stupid

 

12.  The endosymbiont theory talks about the beginnings of

_______         a. Chloroplasts                 b. Multicelled systems                 c. Life on land
                      d. Genetics                                e. My nervous breakdown

 

SHORT ANSWER.

Answer any eight of the following questions for 4 Points Each.
Note: if you answer more than eight, only the first eight will be corrected.
You can get partial credit on these answers.

1.  The rate at which things evolve is closely linked to two other rates. What are they? (Not looking for the two different patterns of evolution rates here!)


 
2. Briefly describe the Gaia hypothesis.

 

 
3. What circumstances bring about a bottleneck effect?

 

 
4. Briefly explain the "plant problem" that faced early theorists for the origins of Life.

 

 
5. There are several widely-accepted explanations for how mass extinctions are caused. What are two?


 
6. Define heterotroph.

 

 
7. Give two non-human examples of memes in Nature.
 

 

8. What are two types of energy that could have been easily used by molecules during the very earliest stages in the development of Life on Earth?
 

 
9. Briefly explain how molecular clocks are supposed to work.

 

 
10. RNA has two different abilities that make it a good candidate for the first living molecule systems. What are they?
 

 
11. A gene is a stretch of (A) - What molecule? whose specific purpose (modern definition!) is to (B) .
A -

 

 B -
12.  Briefly explain the circumstances under which the first protocells were supposed to have formed.

 

 
13.  Explain what is meant if two genes have linkage.

 

 
14.  Some living things still today have almost the exact same form that their distant ancestors had. What circumstances typically lead to such a situation?

 

 

 

 

LONG ANSWER.

Answer any four of the following questions for Eight Points Each.
Note: if you answer more than four, only the first four will be corrected.
You can get partial credit on these answers.

1. For sexual reproduction, in general -
Definition -

 

 

 

 Advantage over asexual
reproduction -
 

 

 Advantage asexual has
over sexual -

 


 

2. Briefly describe (don’t just give labels!) four basically different types of evolutionary isolation.
 

 
 

 

 

3.  When organisms moved onto the land, there were many new conditions that they had to adapt to. Briefly explain four different ways that the conditions differed from living in the water.
 

 
 

 

 

4. For each step in the theoretical development of Life on Earth, put them in chronological order, from earliest to latest, 1 - 8 in the boxes to the left.

Photosynthesis

Eukaryote
Cells

Molecular
Evolution

Cambrian
Explosion

Movement onto Land

Primordial
Soup

Aerobic
Respiration

Multicelled
Systems

5. What are four different conditions that a "Hardy-Weinberg population" must have?
 

 

 
 

 

 

 

6A.  Two critical features that early molecular systems had to have to be considered the first steps of "Life" on Earth -
 

 

 
6B.  Two critical features that didn’t have to be there right at the beginning, but had to develop early because all modern Life has them -
 

 

 

  

 

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. You can get partial credit on these answers.

What, according to a hypothesis about Earth’s past, is Nemesis? Three Points.

 

Why were pea plants the organism that Mendel did his experiments on? Three Points.

 

For what adaptive situations has alternation of generations arisen in various groups? Three Points each.

 

What famous scientist is considered the founder of biogeography? Three Points.

 

Breeding of close relatives can be a good thing, evolutionarily. How? Three Points.

 

About how quickly do the continents generally drift? Three Points.

 

The political wing of Creation "Science" has recently been replaced by another approach. What is it? Three Points.

 

What evidence in the fossil record is there for the appearance of photosynthesis (Two Points), and why is that evidence there? (Four Points)

 

 

What was the first fossil clue for the Snowball Earth period? Three Points.


 
     

Michael McDarby.

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