Biology Final   The speciation episode described in the question 37 (160) is most likely a case of Mimulus lewisii and M

1. The speciation episode described in the question 37 (160) is most likely a case of

polyploidy

2. Mimulus lewisii and M. cardinalis are plants that do not hybridize in nature but can be readily crossed in the laboratory to produce fertile offspring. Which of the following is least likely to keep the gene pools of these two plants separate in nature?

geographic isolation

3. According to the punctuated equilibrium model,

most new species accumulate their unique features relatively rapidly as they come into existence. (chnage most as they branch off from parent species than change little for the rest of their existence)

4. A genetic change that caused a certain Hox gene to be expressed along the tip of a vertebrate limb bud instead of farther back made possible the evolution of the tetrapod limb. This type of change is illustrative of

genetic variation (heterochrony- something changes during vertebrate formation)

5. In the gene pool of a population with 100 individuals, a fixed allele for a particular gene locus has a frequency of

1.0 or 100%

6. Researchers examining a particular gene in a fruit fly population discovered that the gene can have either of two slightly different sequences, designated A1 and A2. Further tests showed that 70% of the gametes produced in the population contained the A1 sequence. If the population is at Hardy-Weinberg equilibrium, what proportion of the flies carries both A1 and A2?

2(.7)(.3)= 42%

7. At a locus with a dominant and recessive allele in Hardy-Weinberg equilibrium, 16% of the individuals are homozygous for the recessive allele. What is the frequency of the dominant allele in the population?

q^2=.16 so q=.4
q+p=1
.4+p=1
1-.4= 0.6

8. The average length of jackrabbit ears decreases gradually with increasing latitude. This variation is an example of

geographic variation or directional selection

9. Which of the following is a polymorphic trait in humans?

blood type

10. Natural selection changes allele frequencies in populations because some _________ survive and reproduce more successfully than others.

individuals