4. cats have a gene that codes for the color of their fur. suppose that a certain breed of cat can have black, gray, or white fur. black fur is dominant, white fur is recessive, and gray fur is intermediate (i. e., cats with gray fur possess one allele for black fur and one for white fur). if a gray cat and a white cat have kittens, what phenotypes could the kittens exhibit •
a) black, gray, or white fur •
b) only gray fur •
c) black or white fur •
d) gray or white fur

D) gray or white fur

Explanation:

Suppose the gene for fur color has alleles B and b. Here, B imparts black fur while b gives white fur. Since B is incompletely dominant over b, the heterozygous genotype "Bb" would give intermediate gray fur. Hence, the cross between gray (Bb) and white cat (bb) would give progeny in 1 gray: 1 white ratio.

the correct answer is b

it has to be understood that the sea water contains a huge amount of sodium and chlorine ions and if they enter the cell of the atlantic cod fish, the cell will shrivel and the fish will die. to avoid such a condition, the fish uses active transport for the purpose of removing the ions against the gradient.

explanation:

the atlantic cod is not a maritime osmoconformer. its native application of salts is less than that of the seawater it lives in. it is continually falling water from the gills to the ocean via osmosis.

countering that, the fish is going to be swallowing seawater. but since its internal collection of salts is lower than seawater, the fish will want to go free of excess salt, and since that's going upon a gradient, then active transport, requiring energy, must be used to pump out the salt. much marine fish use the organs to filter out the salt and these fish discharge very straight urine.