Question

Could someone check my answers, please?

1. Suppose that a species of fish has split into two populations in a lake: one on the eastern side and one on the western side. How could you determine whether the two populations constitute different species?

A. Examine the populations for morphological, color, or other physical differences.

B. Examine the populations for different genetic markers and allele frequencies.

C. Attempt to breed members from the two populations in captivity.

D. Introduce members from one population into the other population’s habitat to see if they interbreed.

(Is it B or D?)

2. A subpopulation of a species of birds migrates to a different location from the rest of the species for breeding purposes. How might the genes change in the subpopulation?

A. Their genes would change randomly and eventually revert to normalcy, which would allow the subpopulation to return to the main population.

B. Their genes would change to better allow them to survive and reproduce in their new location.

C. Their genes would not change at all and they would merely be a subpopulation living in a different location.

D. Their genes would change so that they would continue to be well-adapted to their former location.

(B..?)

3. Hybrids between grizzly and polar bears have been moving farther north. What do you predict about the migration of their hybrid zone over time?

A. It will eventually completely overlap with the range of polar bears.

B. It will eventually completely overlap with the range of grizzly bears.

C. It will continue to move north as the more aggressive grizzly bears take over territory from the polar bears.

D. It will change or remain the same in response to the environmental factors that contribute to the well-being of grizzly and polar bears.

(I'm not quite sure of this one, but is it D..?)

4. Some species undergo polyploidy, which is a multiplication of their chromosomes. That is, they contain full chromosomes from each parent. How could speciation affect a polyploid organism?

A. The polyploid organisms may experience gametic isolation.

B. The polyploid organisms may experience behavioral isolation.

C. The polyploid organisms may experience geographic isolation.

D. The polyploid organisms would not be affected by speciation.

(I think it's A)

5. Suppose that a type of tree tends to speciate over 10 million years and a species of fly tends to speciate over 1 million years. In the event of a mass extinction, which of the following predictions would LIKELY be true?

A. It is impossible to determine how many niches or species the trees and flies would lead to over time.

B. The trees would fill more niches and create more species than the flies.

C. The flies would fill more niches and create more species than the trees.

D. They would both lead to the same number of species.

(C?)

Thank you so much in advance, I really appreciate the help

Answer 1

1- correct option will be D.

Reason - if they move to two different geographical locations , they will be reproductively isolated . So, if we introduce one member of one location to other location , they still won't be able to interbreed.

2- correct option is B

Reason- When birds migrate to different location , they will undergo evolution over time to better adapt to new location as the main purpose of adaptation is to be able to reproduce and survive in new location.

3- correct option is D

Reason - since hybrid will have genes of both parents , so , the environmental factors may change or remain same as since hybrid will have genes of both , the environmental factors will be suitable for both grizzly and polar bear for the hybrid to survive . Because hybrid will also require environmental conditions suitable for the parents.

4- correct option is A

Reason - Multiple organisms in population will end up having same number of chromosomes after polyploidy. As a result, they can reproduce with each other but not with original or parent organisms making them biologically or gametic isolated . It is kind of sympatric speciation i.e. biological isolation without geographical isolation.

5- correct option is C

Reason - as clearly mentioned , flies multiply faster than trees . So , after mass extinction , both tree and flies multiply. As flies will multiply at faster rate than trees , they will fill up more niches.