The extra X chromosome is received from mother.
<h3><u>Explanation</u>:</h3>
Klinefelter's syndrome is the condition of chromosomal aberration where the person has an extra X chromosome. This means the genotype of the person is 44+XXY and the total chromosome number is 47. This condition is achieved due to inappropriate meiotic division and one of the sperm or ovum has the an extra X chromosome.
Here both the parents are normal in terms of colour vision. So the father cannot have the gene of colour blindness because if it was present, then father would have been colour blind because he has only one X chromosome per cell. So its present in mother who is heterozygous in terms of colour blind gene. So the extra X chromosome also came from her which made the presence of two defective X chromosomes in the offspring and made it colour blind.
Father because you inherit traits from your mother and recessive sex linked traits from your father.
C. Endocrine
Definition, relating to or denoting glands which secrete hormones or other products directly into the blood.
