Chapter 11, Problem 33A

Summary Introduction

To illustrate:

The result of male fetal cells that showed an extra X chromosome in the karyotype.

Introduction:

Fetal test is done on couples who suspect they might be carriers of certain genetic disorders. Older couples also want to know the chromosomal status of their developing baby. Various types of fetal tests are available for observing both the mother and the baby. Karyotypes are micrographs of chromosomes that help in detecting chromosomal abnormalities.

Answer to Problem 33A

Fetal tests give results in the form of karyotypes. So the karyotype developed by the technician shows an extra X chromosome. This will cause fetus to suffer from Klinefelter’s syndrome.

Explanation of Solution

Fetal tests are given in the form of karyotype to diagnose any defect in chromosomes. They help in diagnosing chromosomal abnormalities and genetic defects. The technician found an extra X chromosome while constructing a karyotype from male fetal cells.

An extra X chromosome indicates nondisjunction in human sex chromosomes. This condition results from fertilization with a gamete that had two X chromosomes. The male fetus has 2 X chromosomes and one Y chromosome. This causes a disorder called Klinefelter’s syndrome.

Hence the fetus whose test was conducted will suffer from Klinefelter’s syndrome.