In people with sickle-cell disease, red blood cells break down, clump, and clog the blood vessels. the blood vessels and the broken cells accumulate in the spleen. among other things this leads to physical weakness, heart failure, joint pain, and brain damage. such a suite of symptoms can be explained by

a) a bacterial infection interacting with the sickle-cell allele
b) the pleiotropic effects of the sickle-cell allele
c) the polygenic nature of sickle-cell disease
d) an epistatic interaction between the sickle-cell allele and a proteolytic enzyme gene
e) side effects of the drugs used to cure sickle-cell disease

(B) the pleiotropic effects of the sickle-cell allele

Explanation:

This is because the expression of a single mutated sickle cell gene,produces many consequences( pain at joints, heart failure,stroke, ) through out the body.

that is it has  multiple effects from a single gene

try using substitution:

x + y - 6 = x - y. (i'm not giving you the exact answer). since 0 = x - y, then sub 0 in the equation with x - y. combine your like terms, and then use inverse operations, and you'll have your answer.

: -)

ecological efficiency: % of usable energy transferred as

biomass from one trophic level to the next typical is 10% efficient (90% of

energy is lost),is diagramed as the pyramid of energy flow. then osprey eagle

are tertiary consumer and the shrimp are primary consumer, so to balance

mass of shrimp (1/0.1) / 0.1 = 100 kg