Acertain kind of snail can have a right-handed direction of shell coiling (dd or dd) or left-handed coiling (dd). however, if direction of coiling is due to a protein deposited by the mother in the egg cytoplasm, then a dd egg-producing snail and a dd sperm-producing snail will have offspring of which genotype(s) and phenotype(s)?

A certain kind of snail can have a right-handed direction of shell coiling (DD or Dd) or left-handed coiling (dd). However, if direction of coiling is due to a protein deposited by the mother in the egg cytoplasm, then a Dd egg-producing snail and a dd sperm-producing snail will have offspring of which genotype(s) and phenotype(s)?

A. all Dd; half right-coiling and half left-coiling

B. all Dd; all right-coiling

C. 1/2 Dd:1/2 dd; all right-coiling

D. 1/2 Dd:1/2 dd; half right-coiling and half left-coiling

D. 1/2 Dd:1/2 dd; half right-coiling and half left-coiling

Explanation:

right-handed direction of shell coiling (DD or Dd)

left-handed coiling (dd)

If a Dd egg-producing snail and a dd sperm-producing snail breeds together, we will have the following type of offspring

Dd × dd = ( Dd, Dd, dd, dd )

Genotype = 2/4 =1/2 (Dd, dd)

Phenotype = 2/4 =1/2  (Dd, dd)

Thus , option D is the right answer , (1/2 Dd:1/2 dd; half right-coiling and half left-coiling)

regulation of gene expression. gene expression can be regulated by various cellular processes with the aim to control the amount and nature of the expressed genes. these regulatory proteins bind to dna and send signals that indirectly control the rate of gene expression

explanation:

trachea, alveoli, lung capillaries, arteries