I think that having an extra chromosome 21 is tolerable to the point that someone with this condition can survive to maturity because it does not replicate.
There should only be a pair of chromosome 21. In the event that there are 3 chromosome 21, the person that has this extra chromosome has Down syndrome. Changes in the number and structure of this chromosome may result to delayed development, intellectual disability, but not immediate death.
Answer:
b. DNA replication occurs only during the G1 phase of the cell cycle.
Explanation:
A protostar forms once the nebular cloud condenses and the core begins to heat. To heat is the answer hope this helps you!!
Answer:
The activation of DNA synthesis may result from the stimulatory activity of one or more cytoplasmic factors and In fusions of cells in G2 and S, however, nuclei continue their previous activities,
Explanation:
Most of all cell enzymes are proteins
