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प्रश्न
Given below are the F2 – phenotypic ratios of two independently carried monohybrid crosses :
(i) 1 : 2 : 1
(ii) 3 : 1
Mention what does each ratio suggest.
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उत्तर
(i) 1 : 2 : 1 - Phenotypic ratio
Suggest that the phenomenon is incomplete dominance
* When neither of the alleles of a character is completely dominant over the other and the F1 hybrid is intermediate between the two parents, the phenomenon is Incomplete dominance.
* The phenotypic and genotypic ratio in F2 generation is 1:2:1 in this case.
(ii) 3:1 - Phenotypic ratio
Suggest that the phenomena has monohybrid cross. Monohybrid cross is a cross which involves only a single pair of contrasting characters. The parental generation has genotype for pure gene which on cross produces homozygous progeny i.e. F1 generation. On selfing F1 generation obtain F2 generation. The F2 generation has phenotypic ratio 3 : 1.
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संबंधित प्रश्न
Differentiate between the following:
Dominance and Recessive
Differentiate between the following:
Homozygous and Heterozygous
Mention whether the cross is a monohybrid or dihybrid.
What is a monohybrid cross? How did Mendel perform this cross?
A certain couple got four daughters in a sequence and no son. Does it mean that the husband does not produce Y-chromosome bearing sperms? Explain. What is the chance of this couple having a daughter?
Name the conditions when both the alleles are identical?
A garden pea plant produces axial white flowers. Another of the same species produced terminal violet flowers. Identify the dominant trait?
A pure tall plant (TT) is crossed with the pure dwarf plant (tt), what would be the F1 and F2 generations? Explain.
Pure-bred tall pea plants are first crossed with pure-bred dwarf pea plants. The pea plants obtained in the F1 generation are then selfed to produce F2 generation of pea plants.
What do the plants of the F1 generation look like?
