Answer:
The correct answer would be - d. With the end of genetic isolation gene flow took place
Explanation:
It is given that people of Troublesome Creek Kentucky were isolated and have a rare recessive allele that results in a blue tone to their skin. However, later these isolated people connected with the people from outside, and due which allow them to intermate. Intermating among populations from isolated and people from outside leads to gene flow.
Methemoglobinemia was present in the isolated population as they had both recessive alleles in their genotype and other hand people from outside might have heterozygous or both dominant allele genotypes that make them free from this disorder.
Due to the intermating and gene flow, the number of heterozygous conditions rises and after many generations slowly methemoglobinemia could have disappeared due to the masked recessive allele.
Answer: The utilization of different resources requires different adaptations, selecting for different traits.
Explanation:
answers to whole quick check
Birds with larger beaks were better able to utilize the large seeds.
DNA analysis shows that their DNA is almost identical with only minor changes.
The diversity in environments on each island provides many opportunities to study how related organisms have adapted over time.
Scientists observe the frequency of the different forms of the gene and how it changes in response to the environment.
Answer and Explanation:
During an experiment, data from an experimental group are compared with the data of a control group. These two sets are identical in all aspects except for the independent variable that the researcher changes in the experimental group to observe how they affect the individuals. This variable keeps constant in the control group.
The experimental group is the one that receives the experimental procedure, with changes in the independent variable. There can be several experimental groups.
In the control group, the variable measured keeps constant, not influencing the results. This isolates the effect of the independent variable on the experiment and helps to find alternative explanations to the different results.
In the exposed example:
- Control group: Certain amounts of fishes exposed to a normal number of light hours per day. For example, if under natural conditions in its original environment the species is exposed to 12 hour light, then the control group should be exposed constantly to 12 hours light a day to maintain its normal reproductive levels.
- Experimental group: Certain amounts of fishes, equal to the control group, exposed to a different number of light hours per day. For example, there might be 5 experimental groups: one of them exposed to 4 hours light, a second group exposed to 8 hours light, the third group exposed to 12 hours light (The same as the control group), the fourth group exposed to 16 hours light, and the fifth group exposed to 20 hours light.
Except for light, the rest of the variables should be the same for all the groups.
<u>Answer:</u>
The “wheelchair belt” mechanism is the most important mechanism to have on the wheel chair.
<u>Explanation:</u>
- As the patient have very poor control over his trunk so a belt will be perfect to prevent him from falling out of the wheelchair anytime.
- The other options doesn’t make much of important sense than a belt for the patient with muscular dystrophy needs, especially when lost control over the extremities.
- The wheelchair belt will help him in staying in the wheelchair freely without risk of falling off.
<span>Structurally, plant and animal cells are very similar because they are both eukaryotic cells. They both contain membrane-bound organelles such as the nucleus, mitochondria, endoplasmic reticulum, golgi apparatus, lysosomes, and peroxisomes. Both also contain similar membranes, cytosol, and cytoskeletal elements.</span>
