Answer the following question.

Question 13 Marks

Short note : Turner syndrome.

Answer

Turner syndrome is a disorder arising in women due to abnormality in sex chromosomes.
Turner syndrome arises due to either inheritance of only one X chromosome from parents or due to inactivation of the gender- related part of X-chromosomes.
Instead of the normal 44 + XX condition, women suffering from Turner syndrome show a 44 + X condition.
Such women are sterile i.e. unable to have children due to improper growth of the reproductive organ.

Question 23 Marks

Short note : Polygenic disorders.

Answer

Polygenic disorders are caused due to mutations in more than one gene.
In most such cases, their severity increases due to effects of environmental factors on the foetus.’
Common examples of such disorders are cleft lip, cleft palate, constricted stomach, spina bifida (a defect of the spinal cord), etc. Besides diabetes, blood pressure, heart disorders, asthma and obesity are also polygenic disorders.
Polygenic disorders do not strictly follow Mendel’s principles of heredity.
These disorders arise from a complex interaction between environment, life style and defects in several genes.

Question 33 Marks

Short note : Albinism

Answer

Albinism is a monogenic disorder.
Our eyes, skin and hair have colour due to the brown pigment melanin. In this disease, the body cannot produce melanin.
The skin becomes pale, hair are white and eyes are usually pink due to absence of melanin pigment in the retina and sclera.

Question 43 Marks

Name some dominant and recessive characteristics seen in human beings.

Answer

Some dominant and recessive characteristics of human beings.

Question 53 Marks

What are the main objectives of National Health Mission?

Answer

The main objectives of National Health Mission are:

Science Answer the following question.