Let's say you have a person with Aa and a person with Aa
Answer:
Increased frequency of the allele for sickle cell anemia
Explanation:
Sickle cell anemia is fatal in homozygous genotype. The homozygous genotype having two copies of the allele for sickle cell anemia is not favored by natural selection due to its reduced survival success.
However, the heterozygous genotype for sickle cell anemia with one allele for the disease exhibit malaria resistant. The presence of one allele is not fatal for the organisms as the presence of one normal allele ensures the formation of some normal hemoglobin protein and RBCs to support the oxygen delivery to the body parts.
The increased survival success of heterozygous genotype in malaria-prone regions allowed their natural selection. This increased the frequency of allele for the sickle cell anemia in the gene pool of the local population and increased the frequency of heterozygous dominant genotype.
Answer:
A. To cause intact DNA to precipitate, so the activity of DNase can be determined.
Explanation:
The presence of DNase is special feature for some species of bacteria and can be used for identifying them. During DNase test, diluted hydrochloric acid (HCl) can be poured onto the agar plates so that there will be a clear zone close to the bacteria colonies. Each nucleotides are soluble in diluted HCl. But DNA is not soluble in the diluted HCl, thereby making the DNA to precipitate in the rest of the plate.
