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प्रश्न
Describe quantitative inheritance controlled by two pairs of genes.
उत्तर
- Quantitative inheritance is also known as polygenic inheritance in which characters are determined by two or more gene pairs which have additive or cumulative effect. These genes are called cumulative gene or polygenes.
- This quantitative inheritance can be explained by wheat kernel colour which is controlled by two pairs of genes Aa and Bb.
- H. Nilsson Ehle crossed red kernelled variety of wheat with white kernelled variety.
- Gene A and B determine the red colour of kernel (responsible for producing red pigment) and are dominant over their recessive allele a and b which do not produce red colour pigment and the expression is white, if dominant gene is not present. Thus, genotype of a parent with
red kernels is AABB and that of parent with white kernels is aabb. Genotype of F1 hybrids is AaBb. - Continuous variations in expressions is observed as each dominant gene produces specific amount of pigment and the shade of red colour, depends on number of dominant gene present
as shown in Punnett square. 
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संबंधित प्रश्न
In a homozygous plant round seeds (R) are dominant over wrinkled seeds (r) : Draw a Punnett square to show the gametes and offspring when both the plants have heterozygous round seeds (Rr).
Choose the correct answer:
Mendel used ______ pairs of a characters for his experiments.
Give Reason:
In the honey bee, the female is diploid and the male is haploid.
Multiple Choice Question
Who among the following is called father of genetics?
A typical Mendelian dihybrid ratio of F2 generation is 3:1.
Dominant allele refers to ______.
Which one from those given below is the period for Mendel's hybridization experiments?
______ pairs of contrasting traits were studied by Mendel in pea plant.
The genotype of a plant showing the dominant phenotype can be determined by ______.
Mendel was the first biologist to ______
