Question

can you answer

Which of the following best defines gene flow?
the sum of all genetic traits in a population’s individuals at a given time
any movement of genes from one population to another
any movement of organisms from one environment to another
the random change in the frequency of an allele in a population

In a few generations, this population of beetles changed.

A group of bugs includes 13 black bugs and 4 green bugs. After a few generations, there are 13 green bugs and 4 black bugs.

Which is the most likely explanation for the change?
The beetle population moved to a greener habitat.
A natural disaster almost caused the extinction of the population.
The beetle population’s food sources decreased dramatically.
A mutation resulted in a new color of insect.

A high population of greater prairie chickens once inhabited the prairies of Illinois. The conversion of the prairies into agricultural land caused the chickens to lose their habitat. Studies have concluded that this change greatly reduced the greater prairie chicken population. The habitat loss also resulted in a decrease in the population’s genetic variation.

Which change in the gene pool occurred in the greater prairie chicken population?
gene mutation
gene flow
genetic drift
genetic resistance

Which environmental factor could lead to a decrease in genetic variation in a population of tuna?
an increase in food availability
an increase in pollution
a decrease in tuna fishing
a decrease in tuna predators

Which environmental factor would likely lead to an increase in genetic variation in a population of squirrels?
an increase in predators
an increase in available food
an increase in forest fires
an increase in pollution

Answer 1

1) Which best defines gene flow?
Answer: any movement of genes from one population to another.
Why: Gene flow is the transfer of alleles between populations (usually via migration).

2) Beetles changed from 13 black/4 green to 13 green/4 black. Most likely explanation?
Answer: The beetle population moved to a greener habitat.
Why: A habitat change that favors green beetles would produce selection for green coloration over a few generations; a single mutation or food change is less likely to produce that rapid, directional shift.

3) Prairie chickens lost habitat and genetic variation. Which change in the gene pool occurred?
Answer: genetic drift.
Why: Habitat loss and population decline cause bottlenecks and random changes in allele frequencies (genetic drift), reducing variation.

4) Which environmental factor could lead to a decrease in genetic variation in tuna?
Answer: an increase in pollution.
Why: Pollution can kill individuals and shrink populations, increasing drift and reducing genetic variation.

5) Which environmental factor would likely lead to an increase in genetic variation in squirrels?
Answer: an increase in available food.
Why: More resources typically support a larger population size, allowing more mutations and greater genetic diversity.