Which genetic or chromosomal abnormality below is correctly matched with its description?
A) In phenylketonuria the child is unable to produce a critical enzyme,which results in an accumulation of poisons,and in turn causes mental retardation.
B) In Tay-Sachs disease,the body starts producing abnormally shaped red blood cells.
C) In Down syndrome,the brain tissues of the cortex degenerate,resulting in the death of the child.
D) In Sickle-cell anemia,the child receives an extra chromosome resulting in mental retardation.

Question

Quizplus · Accepted Answer

Phenylketonuria (PKU) is a genetic disorder that causes mental retardation due to the inability to produce a critical enzyme called phenylalanine hydroxylase, resulting in an accumulation of poisons.

B, C, and D are incorrect:
B) Tay-Sachs disease is a genetic disorder that affects the central nervous system, causing progressive deterioration and death of nerve cells. It does not affect red blood cells.
C) Down syndrome is a chromosomal abnormality that results in intellectual disability and some physical differences, but it does not cause degeneration of brain tissue.
D) Sickle-cell anemia is an inherited blood disorder that results in abnormal hemoglobin molecules, causing red blood cells to become crescent-shaped. It does not involve an extra chromosome.

Which Genetic or Chromosomal Abnormality Below Is Correctly Matched with Its