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प्रश्न
How does a mutagen induce mutation? Explain with example.
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उत्तर
A mutagen is a physical or chemical agent that changes the genetic material, usually DNA. Different mutagens act on the DNA differently. Powerful mutagens may result in chromosomal instability, causing chromosomal breakages and rearrangement of the chromosomes such as translocation, deletion, and inversion. Ionizing radiations such as X-rays, gamma rays and alpha particles may cause DNA breakage and other damages. Ultraviolet radiations with wavelength above 260 nm are absorbed strongly by bases, producing pyrimidine dimers. Radioactive decay, such as 14C in DNA which decays into nitrogen.
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संबंधित प्रश्न
Give one example of point mutation.
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.
Why did the treatment provided to girl A required repeated visits?
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 |
Haploid plants are preferred over diploids for mutation study because in haploids ______.
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?
One of the parents of a cross has mutation in its mitochondria. In that cross, that parent is taken as a male. During segregation of F2 progenies that mutation is found in ______.
Rate of mutation is affected by ______.
A change of single base pair in the gene for beta-globin chain (in human haemoglobin) results in the change of amino acid residue glutamic acid to valine which is due to ______
A strong mutagen is:
How are alleles of particular gene differ from each other? Explain its significance.
Variations caused due to mutations are ______.
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 a diploid | iii) Trisomy |
| D. Two individual chromosomes lose their diploid | iv) Double chromosome |
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 |
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 |
