<span>Unidirectional flow in the heart is ensured because the heart contains valves that prevent backflow.
These valves keep the flow of the heart going in one direction (hence the name "unidirectional").</span>
A person can only show a recessive trait if both of their parents carried at least one copy of each of the recessive allele. The parents do not need to show the trait, as one copy is not enough to reveal it, but they must both carry it.
Hope this helped!
Two key characteristics of a good scientific investigation are hypothesis and observation of whatever organism your studying.
Answer:
12. In our somatic (body) cells, we have 2N chromosomes, but in our sex cells (sperm & eggs), we have half the number of chromosomes, which is N chromosomes
Explanation: