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प्रश्न
Give an account of incomplete dominance with a suitable example.
उत्तर
Incomplete dominance:
- Incomplete dominance is a deviation from Mendel’s law of dominance.
- In incomplete dominance, both the alleles (genes) of an allelomorphic pair express themselves partially.
- One allele (gene) cannot suppress the expression of the other allele (gene) completely.
- In such a case, there is an intermediate expression in the F1 hybrid.
- In Mirabilis jalapa, if a red-flowered (RR) plant is crossed with a white-flowered (rr) plant, then F1 offspring have pink (Rr) flowers.
F2 Generation: Selfing of F1
Result:
Genotypic ratio - 1 RR : 2 Rr : 1rr
Phenotypic ratio - 1 Red: 2 Pink :1 White
APPEARS IN
संबंधित प्रश्न
In a homozygous pea plant, axial flowers (A) are dominant over terminal flowers (a).
(i) What is the phenotype and genotype of the F1 generation if a plant bearing pure axial flowers is crossed with a plant bearing pure terminal flowers?
(ii) Draw a Punnett square board to show the gametes and offsprings when both the parent plants are heterozygous for axial flowers.
(iii) What is the phenotypic ratio and genotypic ratio of the above cross shown in (ii)?
(iv) State Mendel’s Law of Dominance.
(v) Name two genetic disorders commonly seen in human males.
A homozygous tall plant (T) bearing red coloured (R) flowers is crossed with a homozygous dwarf (t) plant bearing white (r) flowers :-
(i) Give the genotype and phenotype of the plants of F1 generation.
(ii) Mention the possible combinations of the gametes that can be obtained from the F1 hybrid plant.
(iii) State the Mendel’s law of Independent Assortment.
(iv) Mention the phenotypes of the off springs obtained in F2 generation.
(v) What is the phenotypic ratio obtained in F2 generation?
State Mendel’s law of Dominance.
Predict the genotype and phenotype of the following cross in pea.
TTrr x ttRR
(Capital letters show dominance)
Choose the correct answer:
If a homozygous tall plant is crossed with a heterozygous tall plant, the proportion of tall progeny would be ____________
Explain Mendel’s Monohybrid cross. Give an example.
According to Mendel alleles have the following character ______.
The crossing of F1 to homozygous recessive parent is called ______.
If two pea plants having red (dominant) coloured flowers with unknown genotypes are crossed, 75% of the flowers are red and 25% are white. The genotypic constitution of the parents having red coloured blowers will be:
Test Cross is a cross between:
