Mongolism syndrome is caused by

English

Gujarati

Hindi

4.Principles of Inheritance and Variation

normal

Mongolism syndrome is caused by

A

One extra chromosome

B

One extra sex chromosome

C

One extra chromosome in 21st pair

D

One less sex chromosome

Solution

(c) Mongolism or Down’s syndrome is caused by nondisjunction of $21^{st}$ chromosome pair during anaphase $I$.

As a result $(n + 1)$ gametes are formed.

Fertilization with normal gamete $(n)$ result in trisomy $(2n + 1).$

Standard 12

Biology

Share

Similar Questions

Which one of the following mutation partially or fully reverses the harmful effects of previous mutation

normal

Which of the following is not a hereditary disease

normal

(AIPMT-2005)

Who worked on poky strain of Neurospora

normal

Coupling and repulsion are the two faces of

normal

Chiasma shows the sites of

normal