Question

Down syndrome occurs when an individual has an extra copy of chromosome 21.

This additional genetic material alters development and results in Down syndrome.
This genetic abnormality is an example of
Ofertilization.
a substitution.
a mutation.
differentiation.

Answer 1

c. a mutation.

Explanation of why the others are incorrect:

a. Fertilization: Fertilization refers to the fusion of sperm and egg during sexual reproduction to form a zygote, which then undergoes cell division and development. Down syndrome is not caused by a fertilization process, but rather by a genetic abnormality involving an extra copy of chromosome 21.

b. Substitution: Substitution refers to a type of genetic mutation where one nucleotide base in the DNA sequence is replaced by another. Down syndrome is not caused by a substitution mutation, but rather by a trisomy, which is an extra copy of chromosome 21.

d. Differentiation: Differentiation refers to the process by which cells become specialized and acquire specific functions during development. Down syndrome is not related to the process of cellular differentiation, but rather to a genetic abnormality involving an extra copy of chromosome 21, which alters development and results in Down syndrome.