The answer is in the image attached.
Hope this helps!
The answer is DNA because genotype is the genes of an organism and genes = DNA.
Explanation:
In the majority of cases, the extra copy of chromosome 21 comes from the mother in the egg.
In a small percentage (less than 5%) of cases, the extra copy of chromosome 21 comes from the father through the sperm.
In the remaining cases, the error occurs after fertilization, as the embryo grows.
This is the first stage of mitosis and meiosis whereby the specialized cell is undergoing, cell division.
The nuclear envelope starts to break down
The chromosomes start to condense during this phase, from being loose to being tight, held together at the middle.
The mitotic spindles start forming, as well from the spindle apparatus.
Brainliest please.
