Answer Happy

In a species of fish, an observable trait is determined by a
gene for which there are only two
alleles, p and q,
and p is completely dominant
over q. Which of the following
graphs best represents genetic drift in
this population?
2.
You are studying the life cycle of the cane toad, a large
terrestrial amphibian native to Central and South America. You know
that the habitat of the cane toad sometimes experiences periods of
intense heat with little precipitation. Which is
the best scientific justification of why
the cane toad is able to survive these hot, dry periods?
A> The toad enters a time of hibernation.
B. The toad responds to photoperiodism.
C> The toad undergoes a period of estivation.
D. The toad will migrate.
3. The graph below shows changes in the number of families
of organisms that existed during a time period in Earth's history.
Which of the following describes what would most
likely be happening between points Y and Z on the
graph?
A. Adaptive radiation is occurring following a mass-extinction
event.
B. A mass extinction is occurring as a result of changing
environmental conditions.
C. Genetic variation is increasing as a result of the fusion of
hybrid zones.
D. The total population of organisms is increasing as a result
of genetic drift.
4. Over many generations, why have certain insect species
become more resistant to insecticides?
A. Disruptive selection has allowed only the extreme phenotypes
to survive.
B. Only advantageous phenotypes have been able to
reproduce.
C. Only the intermediate genes are allowed to be passed on to
offspring.
D> Stabilizing selection has allowed only the intermediate
insects to survive.
1 0.8 0.6 0.4 0.2 pallete Allele Frequency - allele 2 4 6 8 Generation 1 0.8 0.6 Allele Frequency x 0.4 p allele - allele 0.2 0 0 2 4 6 8 8 00 Generation

1 0.8 0.6 Allele Frequency 0.4 "pallele * allele 0.2 0 0 2 6 8 4 Generation 1 0.8 0.6 Allele Frequency 0.4 -p allele - allele 0.2 0 0 2 4 6 8 Generation

800 Z Number of families 500 0 Time (million years)