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प्रश्न
What is chromosomal aberration? Give any two types of aberrations found in the population.
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उत्तर
- Definition: The structural and morphological change in chromosomes due to rearrangement is called chromosomal aberrations. It changes the gene arrangement (order or sequence) that results in the variation. Chromosomal aberrations occur due to the following reasons:
- Deletion: Loss of genes from chromosome.
- Duplication: Genes are repeated or doubled in number on chromosomes.
- Inversion: A particular segment of the chromosome is broken and gets reattached to the same chromosome in an inverted position due to 1800 twist. There is no loss or gain of the gene complement of the chromosome.
- Translocation: Transfer (transposition) of a part of a chromosome or a set of genes to a non-homologous chromosome is called translocation. It is affected naturally by the transposons present in the cell.
संबंधित प्रश्न
Define evolution. How does it occur?
Some plants occur in one of the two sizes : tall or dwarf. This characteristic is controlled by one pair of genes. Tallness is dominant to dwarfness. Choose suitable letters for this gene pair.
Which of the following gas was not present in early earth atmosphere?
(a) Ammonia
(b) Oxygen
(c) Hydrogen sulphide
(d) Methane
Out of the wing of a bird, wing of an insect and the wing of a bat :
which two are analogous organs?
Give one example each of characters that are inherited and the ones that are acquired in humans. Mention the difference between the inherited and the acquired characters.
Write short note based upon the information known to you.
Evolution
Explain the following :
(a) Speciation
(b) Natural Selection
Define the Gene pool.
Transfer of a part of chromosome or set of genes to a non-homologous chromosome is called ________.
The idea of mutation was brought forth by:
