bio past question (1 Viewer)

[stressedadfff]

hey guys, could anyone explain the following:

 

[Eagle Mum]

C is wrong because Klinefelter syndrome also comprises 47 chromosomes with an extra X (ie. sex chromosome set is XXY).
D is wrong because although Patau syndrome does comprise 47 chromosomes, the extra chromosome 13 is an autosomal, not a sex chromosome.

 

[[Blank]]

Trisomy 21 causes the person to have an extra 21st chromosome. A normal person has 46 chromosomes, so 46+1 = 47. Chromosome 21 is an autosomal chromosome. So A is correct
B is wrong Edwards syndrome adds an extra 18th chromosome. So the number of chromosomes won’t be 36

DAMN IT HIVA! I WAS GOING TO ANSWER THIS ONE!!

 

[[Blank]]

You can still answer it,

I was only going to say that Down Syndrome is the adding of an extra of chromosome 21. Since it shows that the total number was 47, (one over the normal amount in humans), it's the correct answer.
After that, you wouldn't really worry about the other answers since you know which one is correct now.