Sunlight exposure has stronger effect on skin cancer risk in fair-skinned humans than in individuals with darker skin. This is a
n example of: a. Differences in the norm of reaction.
b. Pleiotropy.
c. Epistasis.
d. All of these choices are correct. genotype-by-environment interaction.
Genotype by environment interaction refer to a situation where two different genotypes react differently in an environment. Light skinned humans are at greater risk of skin cancer because they lack melanin which the dark people have and this melanin protect the skin from sun.
All the choices are correct. Differences in the norm of reaction I.e they react different way.
Epistasis is when the effect of a gene suppress the other.
Pleiotrophy is when a gene influence another genes phenotipically. These are all genotype enviromr interaction.
Homeostasis is maintained by negative feedback loops within the organism. In contrast, positive feedback loops push the organism further out of homeostasis, but may be necessary for life to occur. Homeostasis is controlled by the nervous and endocrine systems in mammals.
