In mussels, brown coloring (b) is dominant and blue coloring(b) is recessive. a homozygous brown mussel crosses with a blue mussel. what percentage of offspring are expected to be blue?

A homozygous brown mussel crosses with a blue mussel. The percentage of offspring are expected to be blue 0%

Explanation:

homozygous brown means BB= which is dominant

while the blue mussel too is bb= homozygous blue recessive  

After crossing, it would result into having Bb, Bb, Bb, Bb which are all heterozygous dominant brown which is 100% brown because the colour brown is dominant over the blue colour.

idk

explanation:

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.