Answer:
A. aneuploidy; trisomic
Explanation:
Aneuploidy means having more numbers of chromosomes than usual while polyploidy means having an abnormal number of chromosome sets. Down syndrome is a trisomy on chromosome 21 meaning there are 3 chromosomes for chromosome set 21.
Answer: Brain stem
Explanation:
The brainstem can be defined as a structure which is present in between the midbrain and the cerebrum. This controls the flow of information from the brain and the rest of the body. It also controls the functions like breathing, heart rate, consciousness, sleep and wake cycle and blood pressure. The brain stem consists of pons, midbrain and medulla oblongata.
