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प्रश्न
What is point mutation? Give one example.
उत्तर
When heritable changes occur in a very short region of the DNA molecule, such as a single nucleotide or nucleotide pair, these are referred to as point mutations. Point mutations can be caused by inversion, substitution (transition and transversion), or frameshift (insertion and deletion) nucleotide changes in DNA or RNA. Phenylketonuria (PKU; Polling 1934) is an inborn, autosomal, recessive metabolic condition in which the homozygous recessive individual lacks the enzyme phenylalanine hydroxylase, which is required to convert phenylalanine (amino acid) to tyrosine (amino acid) in the liver. It causes hyperphenylalaninemia, which is marked by the accumulation and excretion of phenylalanine, phenylpyruvic acid, and other substances. The enzyme lack is caused by a defective autosomal recessive gene on chromosome 12. This gene is faulty as a result of replacement. Affected child are OK at birth, but within a few weeks, plasma phenylalanine levels spike (30-50 times), impairing brain development. Other signs include mental impairment, reduced pigmentation in the hair and skin, and eczema.
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संबंधित प्रश्न
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?
Assertion (A): Gamma rays are generally used to induce mutation in wheat varieties.
Reason (R): Because they carry lower energy to non-ionize electrons from atom
Draw the diagram of different types of aneuploidy.
Haploid plants are preferred over diploids for mutation study because in haploids ______.
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 ______.
Which one of the following is a sort of chromosomal aberration?
Mutations result in
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 was lost 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 |
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 |
