Question

Foetal sex can be determined from cells present in amniotic fluid by looking for

• A. Kinetochores
• B. Chiasmata
• C. Barr bodies and sex chromosomes
• D. Autosomes

Answer 1

The correct option is C Barr bodies and sex chromosomes

Foetal sex can be determined by using X and Y chromosomes in the cells which are inactive. X chromatin in its inactivated form is present as a mass against the nuclear membrane in females is known as Barr body as it was first named by Barr and Bertem (1949). These Barr bodies are present in 40% of females who are considered as chromatin positive and absent in males who are considered as chromatin negative. For amniotic fluid, a method for determining foetal sex by identification of Barr-Body is by staining with aceto-orcein

So, the correct answer is 'Barr bodies and sex chromosomes'.