In some parts of Africa, the frequency of heterozygosity for the sickle cell anemia allele is unusually high, presumably because this reduces the frequency of malaria. Such a relationship is related to which of the following? a) Mendel's law of independent assortment
b) Mendel's law of segregation
c) Darwin's explanation of natural selection
d) Darwin's observations of competition
e) The malarial parasite changing the allele

The correct option is C.

Explanation:

According to Darwin's Law of Natural Selection, a gene that benefits the organism and helps it produce healty offspring so that it can survive is supported by natural selection and will receive a positive feedback over.

The fact that the heterozygosity for sickle cell anemia helps with the survivability of malaria, which is a deadly disease, suggests that the heterozygosity is favored by the law of natural selection.

I hope this answer helps.

the correct answer is 4) heat and pressure

metamorphic rocks arise from transformation of existing rocks types, in a process called metamorphism. during metamorphism the original rock(prolith) change into metamorphic rock by heating (150-200c) and pressure of more than 1000 bar. the original rock can be sedimentary, igneous, or existing metamorphic rock.