1.) 4
2.) 4
3.) 3
4.) 2
5.) 2
6.) 4
7.) 1
8.) 1
9.) 1
10.) 5
11.) 3
12.) 2
13.) 2
14.) 5
15.) 2
16.) 3
17.) 4
18.) 5
19.) 2
20.) 3
21.) 5
22.) 3
23.) 3
24.) 2
25.) 3
26.) 2
27.) 3
28.) 5
29.) 4
30.) 2
31.) 4
32.) 2
33.) 1
34.) 3
35.) 5
36.) 4
37.) 2
38.) 1
39.) 3
40.) 5
41.) (2) To do this question, you have to assess the allelic makeup of the 5 colonists.
Three of them would be FF
and two of them would be Ff based on the information. Therefore if the makeup of the
five colonists is
FF, FF, FF, Ff, and Ff. With that in mind, the gene frequency for the dominant allele big
F is 8/10 or .8
and little F is .2 That means the percentage of homozygous recessives in the population,
those with attached
ear lobes is q2=.04 so the number of attached ear lobes would be .04 X 10,000 ppl or 400
ppl.
42. 3 Genetic drift is a random change in genetic frequencies which is greater in tiny
populations. This would
also be a classic founder effect.
43. 1 This population having started from five colonists probably had significantly
different genes than the original
population they came from.
44.
45.
46.
47.
48.
49.
1
3
1
2
4
4
Essay Key
1. Student correctly addresses the idea of:




introgression (incorporation of the gene complex of one species into another
species)
polyploidy (a nondisjunction resulting in a complete additional chromosome set)
prezygotic and postzygotic isolating mechanism examples (many examples ...
prezygotic could include temporal isolation and postzygotic could
include formation of an embryo with an odd chromosome number incapable of
forming proper gametes)
relating geographic isolation to allopatric speciation (different geographical areas
may have different conditions resulting in different selection pressures
selecting for different variations of a species)
2. State four of the conditions for Hardy-Weinberg to be true
a. infinitely large population, no gene flow, no mutation, random mating, no natural
selection
b. p2 = .04 (homozygous white) 4,000 rabbits
p = .2 (percentage of recessive white allele)
q = .8 (percentage of dominant agouti allele)
q2 = .64 (64,000 homozygous agouti rabbits)
2pq = .32 (32,000 heterozygous agouti rabbits)
3. a.) Antibiotics have selected against non-resistant varieties of bacteria, while the
resistant varieties have lived and been selected for.
b.) Organisms with more similar nucleic acids and proteins have more similar
evolutionary histories.
c.) Fossils show a record of organisms in the past. A slow change in the fossils with
many transitional forms as one moves upward
through the sedimentary rock strata supports the concept of gradualism, while
abrupt discontinuities in the fossil record are more
supportive of the concept of punctuated equilibrium.
4. a.) Organisms with short generation times, easy to raise, and those that produce large
numbers of offspring with easily visible contrasting
characteristics would be ideal. Organisms fitting these criteria would include mice, fruit
flies, and peas.
b.) Generation one shows a cross between pure dominant and recessive individuals,
producing all heterozygous dominants in the second generation.
The third generation shows the classic results observed in a cross between two hybrid
individuals (a 3:1 dominant : recessive ratio).
c.) As the percentage of homozygous recessives in generation one was 49% (49 out of a
total of 100), in this case q=.7. In generation number 5,
120 out of the total of 480 were homozygous recessive, so q2= .25 (120/480) and
q=.5, so the gene frequency has shifted and therefore
the population from the beginning to the end was not in Hardy-Weinberg equilibrium.