Question

Two parents of normal phenotype have a son with an autosomal recessive linked genetic disorder. What is the most likely cause of this?

Because most of a human's genes are autosomal, it was never noticed that the parents had the condition.

Some environmental effect in the womb caused the child to express the disorder.

Both parents must be heterozygous for the disorder, or carriers.

Because the condition is on the X chromosome and the child only has one copy of the X.

Answer 1

Answer:

Because most of a human's genes are autosomal, it was never noticed that the parents had the condition.

Some environmental effect in the womb caused the child to express the disorder.

Both parents must be heterozygous for the disorder, or carriers.

Because the condition is on the X chromosome and the child only has one copy of the X.

Explanation:

Answer 2

• Two parents with normal phenotype = XX and XY .

• Have a son with an autosomal recessive linked genetic disorder = XᵃY.
• The Mother is carrier because of which this autosomal recessive linked genetic disorder in son is caused.As the son has only one X which comes from mother .
• The mother's phenotype is normal because Mother is carrier and her one X chromosome is normal.
• Therefore the mother should have XᵃX .