I know its not d but it might be c or a
Answer:
Because offspring with two parents will share half of each parent's DNA.
Explanation:
Sex cells contain half of the genetic information of an organism's regular cells. This is because a sexually-produced organism will be unique; it will share genetic information with both of its parents, rather than be identical to its bearer (like an asexual organism would be). When a sex cell meets another sex cell, their DNA will meet as well and change/adapt to suit the organism. If a sex cell had all the information needed to create an embyro, instead of half, which requires another cell's information to fill the DNA void.... well, it would just do it.
Answer:
The flow of individuals in and out of a population introduces new alleles and increases genetic variation within that population. Mutations are changes to an organism's DNA that create diversity within a population by introducing new alleles.
Explanation:
Foods that contain more than one type of molecule help us meet our daily requirement of nutrients. There is a limit to how much we can eat in a day, so if nutrient rich foods are consumed, we can easily provide the necessary building blocks for our bodies to maintain healthy function. This is not possible with foods that contain only one type of molecule.
Answer - Cyanobacteria aka Algae that contributed in creating O2 for the atmosphere as a byproduct thru Photosynthetic.
Reason - Of course Algae make up mainly the whole world in waters and they do photosynthesis to give off oxygen in the atmosphere.