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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
According to de-Vries what is saltation?
Why are traits acquired during the life-time of an individual not inherited?
Out of the wing of a bird, wing of an insect and the wing of a bat :
which two are homologous organs?
Match the terms given in column I with those given in column II :
| Column I | Column II |
| (1) Fossil | (a) A famous evolutionist |
| (2) A theory of evolution | (b) Survival of the fittest |
| (3) Probable ancestor of birds | (c) Petrified remains of prehistoric life |
| (4) Charles Darwin | (d) Father of genetics |
| (5) Gregor Mendel | (e) Archaeopteryx |
Multiple choice question.
Gene frequency in a population remain constant due to –
Short answer question.
Give an example of disrruptive selection
Transfer of a part of chromosome or set of genes to a non-homologous chromosome is called ________.
____________ results in variation in gene frequencies within population by chance rather than by natural selection.
The chronological order of human evolution from early to recent stages is ______.
Define the following term:
Evolution
