Meiosis involves crossing over where chromosomes exchange genetic segments, resulting in different sets of chromosomes. Each time an egg or sperm created, it is different due to this recombination. Mitosis on the other hand is non-sex cells replicating exact copies of themselves which lead to no genetic variation as they aren't involved in producing offspring.
The atria of the heart merely need to allow blood to flow into the ventricle, and therefore aren't very muscular.
The ventricles of the heart need to actually pump blood to the rest of the body, whether to the lungs or the the rest of the body.
<span>gradual movement of the continents across the earth's surface through time. and that explains draft because they were crossing/drafting across the ocean hope that helps</span>
Answer:
because cells build tissues, tissues build organs, organs build organ system.
Both the parents are heterozygous.
https://www.bbc.co.uk/bitesize/guides/z8nxtyc/revision/4
