About 95% of the time down syndrome is caused by “trisomy 21.”the person has three copies of chromosome 21, instead of the usual two copies, in all cells. This is caused by abnormal cell division during the development of the sperm cell or the egg cell.
Answer:
Cell membranes are semi-permeable, which works like a sieve that determines what enters and leaves the cells.
Explanation:
It is semi-permeable and it allows molecules to diffuse inside.
<em>Feel free to mark it as brainliest :P</em>
Answer:
Adaptations develop when certain variations or differences in a population help some members survive better than others. The variation already exist with the population, but the variation comes from a mutation, or a random change in an organism's genes.
Answer:
The answer is strictly between B or D