Answer:
In heterozygotic individuals, the gene for sickle cell anemia is protective against malaria.
Explanation:
Through the same mechanism that the mutation associated with sickle cell anemia produces the disease (altered hemoglobin structure), having a single copy of the mutation (that is, being heterozygotic) provides protection against malaria. This is believed to be due to the altered structure causing difficulty for the malaria parasite when it attempts to enter red blood cells as part of its life cycle.
Today, there are medications to successfully treat malaria, but it still killed 627,000 people in 2020. This represents a significant evolutionary pressure for genes that would prevent serious malarial illnesses. As malaria was and still is common in African regions, the result was a higher prevalence of sickle cell anemia in those of African descent.
Endosteum- a thin, vascular membrane:)
Answer:
b. A change occurs in the environment.
d. Poorly adapted individuals have decreased survivorship.
a. Well-adapted individuals leave more offspring than do poorly adapted
c. Genetic frequencies within the population change.
Explanation:
Genetic variation is the variation in DNA sequences between individuals in a population. Looking at the analogy of the question; there is need to first be a change in the environment. This is being followed by decrease in poorly adapted individuals due to the fact that they wont be able to cope with ambient change in the environment. Therefore, as a result only well- adapted individuals would thrive to leave more offsprings than the poor adapted ones.
As such, Genetic frequencies within the population change with time.
Operating living or growing water for example fish living