Question

can you answer these
A biology teacher asks students to give examples of genetic variations that support the idea that changes in a population’s environment affect genetic variation. Which is the least supportive example?
changes in genetics in human populations
antibiotic resistance in bacteria populations
pesticide resistance in garden insects
changes in the color of the peppered moth population in England

Babies with very low or very high birth weight are less likely to survive. The graph shows the percentage of babies born at different weights.

A graph entitled Percentage of Babies born at Different Weights has weight in pounds on the horizontal axis, and percentage on the vertical axis. A small percentage of babies are born at the low and higher birth weights, and a greater amount are around 7 to 8 pounds.

Which statement is a valid claim that could be made using the data in the graph?
Directional selection is occurring because the graph favors an extreme.
Stabilizing selection is occurring because the average is favored.
Disruptive selection is occurring because the two extremes are favored.
Biodiversity variation is occurring because there is an increase in trait variation.

Which of the following best defines a gene pool?
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

Which best describes biogeographic isolation?
It always leads to the formation of new species.
It cannot lead to evolution.
It is a mechanism for evolution.
It occurs only through geographic forces.

Consider the two male oryx that are shown below.

mc005-1.jpg

Which of Charles Darwin’s main points is depicted in the image?
Organisms within a population compete with each other to survive.
Over time, beneficial variations will be passed on to future generations.
More offspring are produced than can be supported by an environment.
All organisms within a population have an equal chance for survival.

Answer 1

Here are the answers with brief explanations:

1. Least supportive example: changes in genetics in human populations.
- This is vague and not explicitly tied to environmental change, whereas the others are classic examples of environmental pressures driving genetic change.

2. Graph of baby weights: Stabilizing selection is occurring because the average is favored.
- Middle weights have higher frequency/survival; extremes are selected against.

3. Best definition of a gene pool: the sum of all genetic traits in a population’s individuals at a given time.
- (This means the total collection of alleles in a population.)

4. Biogeographic isolation best description: It is a mechanism for evolution.
- Isolation can reduce gene flow and lead to divergence and speciation.

5. Oryx image (Darwin’s point depicted): Organisms within a population compete with each other to survive.
- The image shows competition among individuals, illustrating struggle for existence.