Briefly mention the contribution of T.H. Morgan in genetics.
Solution and Explanation
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Concepts Used:
Chromosomal Theory of Inheritance
Chromosomal theory: Linkage and Genetic Recombination
If two genes were present on the same chromosome, the chances of getting a parental combination were much higher in the next generation in comparison to the non-parental combination. This physical association of genes was termed ‘linkage’. The description of the non-parental gene combinations in a dihybrid cross is termed ‘genetic recombination'. After the discovery of linked genes, the frequency of linked genes also influenced the appearance of traits in the next generation.
Observations of Chromosomal Theory of Inheritance:
- During the cell division-meiosis process, the pairs of homologous chromosomes move as discrete structures, which are independent of other pairs of chromosomes.
- From each homologous pair, there is a random distribution of chromosomes into the pre-gametes.
- Each parent synthesizes gametes, which add up to only half of their chromosomal complement.
- Even though female (egg) and male (sperm) gametes differ in morphology and size, they have the same number of chromosomes, submitting equal genetic contributions from each parent.
- The gametic chromosomes fuse during the process of fertilization to produce offspring with the same number of a chromosome as their parents.
Read More: Chromosomal Theory of Inheritance