Itd seem like a virus would replicating and once the host cell cannot contain the viruses anymore, the cell explodes and releases all the viruses into the blood stream
Answer:
The presence of an additional chromosome
Explanation:
Look at "pair" 21. See how there are THREE chromosomes instead of TWO? Normally, there would only be two chromosomes in each pair but this karyotype shows a trisomy (see def. below) of the 21st pair. This was caused by a nondisjunction mutation of the 21st pair. The is also the karyotype of a person with Down's Syndrome.
Definition of Trisomy:
A condition of the presence of three chromosomes in a pair instead of two. This normally causes developmental irregularity.
Answer:
The X and Y sex chromosomes
Explanation:
The first one according to the graph
