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.
The correct answer in multicellular
Prokaryotic cells lack a defined nucleus, but have a region in the cell, termed the nucleoid, in which a single chromosomal, circular, double-stranded DNA molecule is located.
Answer:
B replication
Explanation:
the teacher demonstrated, so the students were told to CARRY OUT THE *same* experiment, AKA REPLICATION >:3
