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प्रश्न
Explain the law of independent assortment with a suitable example.
उत्तर
When the two homozygous parents differing in two pairs of contrasting traits are crossed, the inheritance of one pair is independent of the other. In other words, when a dihybrid (or poly hybrid) forms gametes, the assortment (distribution) of alleles of different traits is independent of their original combinations in the parents. This law of independent assortment can be explained with the help of a dihybrid cross and dihybrid ratio. The appearance of new combinations in the F2 generation proves the law.
Carry out a dihybrid cross for any two characters till the F2 generation with the phenotypic and genotypic ratio:
Explanation:
A gamete that receives ‘Y’ for colour may receive ‘R’ for shape or ‘r’ for shape. This would result in the formation of YR and Yr types of gametes. Similarly, a gamete that receives ‘y’ for colour may receive ‘R’ or ‘r’ for shape. This would result in the formation of yR and yr types of gametes (Independent assortment).
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संबंधित प्रश्न
Considering the relationship in the first pair, complete the second pair:
rr : Homozygous : : Rr : ....................
The F2 progeny of a monohybrid cross showed phenotypic and genotypic ratio as 1:2:1 unlike that the Mendel’s monohybrid F2 ratio. With the help of a suitable example, work out a cross and explain how it is possible.
What is Neo-Mendelian genetics?
___________ is the scientific name of garden pea, which Mendel used for his experiments.
A pea plant which is homozygous for green pods which are inflated [GGII] is crossed with a homozygous plant for yellow pods which are constricted [ggii]. Answer the following questions;
a) Give the phenotype and genotype of the F1 generation.
Which type of pollination has occurred to produce F1 generation?
b) Write the phenotypic ratio of the F2 generation
c) Write the possible combinations of the gametes that can be obtained if two F1 hybrid plants are crossed.
d) State Mendel’s law of ‘Segregation of Gametes’
5) What is the scientific name of the plant which Mendel used for his experiments on inheritance?
Which one of the following is the phenotypic monohybrid ratio in F2 generation?
Give Reason:
Discontinuous variations are inheritable.
Complete the following sentence with appropriate word:
___________ is the Father of Genetics.
Which of the following characters can be acquired but not inherited?
In the following crosses write the characteristics of the progeny
| Cross | Progeny |
| (a) RR YY × RR YY | __________________ |
| Round, yellow Round, yellow | __________________ |
| (b) Rr Yy × Rr Yy | __________________ |
| Round, yellow Round, yellow | __________________ |
| (c) rr yy × rr yy | __________________ |
| wrinkled, green wrinkled, green | __________________ |
| (d) RR YY × rr yy | __________________ |
| Round, yellow wrinkled green | __________________ |
