Advertisements
Advertisements
Question
Answer the following question.
Two children, A and B aged 4 and 5 years respectively visited a hospital with a similar genetic disorder. The girl A was provided enzyme-replacement therapy and was advised to revisit periodically for further treatment. The girl, B was, however, given a therapy that did not require revisit for further treatment.
Name the ailments the two girls were suffering from?
Advertisements
Solution
ADA (adenosine deaminase) deficiency is a form of SCID (severe combined immunodeficiency)- a type of disorder that affects the immune system. The disease is caused by a mutation in a gene on chromosome 20. The gene codes for the enzyme adenosine deaminase (ADA). Without this enzyme, the body is unable to break down a toxic substance called deoxyadenosine. The toxin builds up and destroys infection-fighting immune cells called T and B lymphocytes.
RELATED QUESTIONS
Give one example of point mutation.
Albinism is known to be due to an autosomal recessive mutation. The first child of a couple with normal skin pigmentation was an albino. What is the probability that their second child will also be an albino?
Rate of mutation is affected by ______.
A strong mutagen is:
How does a mutagen induce mutation? Explain with example.
Match list I with list II.
| List I | List II | ||
| A. | A pair of chromosomes extra with diploid | (i) | monosomy |
| B. | One chromosome extra to the diploid | (ii) | tetrasomy |
| C. | One chromosome loses from diploid | (iii) | trisomy |
| D. | Two individual chromosomes lose from diploid | (iv) | double monosomy |
Match list I with list II
| List I | List II |
| A. A pair of chromosomes extra with diploid | (i) monosomy |
| B. One chromosome extra to the diploid | (ii) tetrasomy |
| C. One chromosome loses from diploid | (iii) trisomy |
| D. Two individual chromosomes lose from diploid | (iv) double monosomy |
What is the classic example of a point mutation?
Which chemical mutagen is a base analogue that replaces thymine?
What structural or numerical changes can occur in chromosomal mutations?
