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)

option c is the correct answer.

before, trains worked using the steam engine. thus, it uses heat so it is crucial to apply heat balance. the steam engine absorbs energy during the stage of boiling water. so, this is the endothermic reaction. when the steam is used to work the piston, it has to release this energy through running the train. the excess energy is released as an exhaust to the chimney. this is the exothermic process because it releases energy to the surroundings.