<span>The correct answer is letter A, disorders in individual genes are responsible for Down's syndrome.
This is a human genetic disorder that is associated with physical growth delays, characteristic facial features, and a mild to moderate intellectual disability. This is a condition in which the genes make a copy of the chromosome 21. </span>
The mitochondrion would be affected the most, this scenario is actually called cellular fatige. hope this helps :)
The name given to a group of similar cells that perform a special function together is tissue.
