Question

1. Women in advanced maternal age are at risk of having a baby with chromosomal abnormalities. Based on the processes in oogenesis, explain the reason behind.

Answer 1

Advanced age result in increased chance of fetal abnormalitis

The major chromosome abnormalities found in fetus are trisomy 21, trisomy 13 as well as trisomy 18 , Klinefelter syndrome etc .

The main reason is due to the Error in division of sec cells that is the meiosis

This is the process by which human body divide the sex cells into 2 with half the number of chromosome. Main sex cells are sperm and ovum . In a normal meosis there will be 23 chromosome for each parent which fuse to form 46 chromosome.

Errors during dividing of sex cells (meiosis)

As the female is born with the egg in their ovary . As the aging process goes in the age of the egg also goes in increasing resulting in the increase in the chromosome abnormalities.

Maternal aneuploidy common in old age . The missegregation of the chromosome in the meiosis is the main reason .

Translocation and defect in meiosis 1 phase and meiosis 2 phase cause chromosome abnormalities and lead to major defect in babies