<h3><u>Answer;</u></h3>
When an area is holoendemic, the HbS allele frequency is between 0.52 and 4.04.
<h3><u>Explanation;</u></h3>
- <em><u>HbS allele is the sickle cell hemoglobin allele that provides immunity to malaria. This is because people with the sickle cell allele have a selective advantage in areas where there is a high incidence of malaria.</u></em>
- Therefore, natural selection will favor the population with HbS allele in a Malaria holoendemic (most individuals are infected) region. The HbS allele frequency in this population is expected to be high.
- After malaria is cured, the frequency of the HbS allele should decrease in regions with a lot of mosquitoes because having one copy of the HbS allele will no longer be advantageous in these regions.
The correct option is: THE ONSET OF NIPPLE GROWTH.
Puberty stage is the stage at which the chemical process which are occurring in a child's body activate the sexual capacity of that child. The signs of puberty in girls include: breast development, skin and hair changes, growth of hair in some part of the body, body growth, etc.
The major homeostatic roles of kidneys in a healthy adults include; Regulation of the extracellular fluid volume, they ensure an adequate quantity of plasma to keep blood flowing to the vital organs. Regulating osmolarity; the kidneys help maintain appropriate concentration of the extracellular fluid with respect to the solutes in the fluid. The kidney regulates ion concentration ; including the sodium, calcium and potassium ions;. They also regulate the body pH; by preventing the blood plasma from being too acidic or basic. Another role is excretion of wastes and toxins, and lastly the production of hormones, such as erythropoietin which stimulates the synthesis of red blood cell.
