NEET Practice Questions (MCQs) with Answers & Solutions

The F1 generation will be Rr (pink). When F1 is self-pollinated, the F2 generation will have a genotypic ratio of 1 RR (red): 2 Rr (pink): 1 rr (white). Therefore, 2/4 or 1/2 of the F2 generation will be pink.

The text explicitly states: 'Heterozygotes produce round seeds, and so B seems to be the dominant allele. But, the starch grains produced are of intermediate size in Bb seeds. So if starch grain size is considered as the phenotype, then from this angle, the alleles show incomplete dominance.'

The text mentions: 'Here the genotype ratios were exactly as we would expect in any mendelian monohybrid cross, but the phenotype ratios had changed from the 3:1 dominant : recessive ratio.' In incomplete dominance, the F2 phenotypic ratio becomes 1:2:1 (e.g., Red:Pink:White in snapdragons).

The text states: 'Therefore, dominance is not an autonomous feature of a gene or the product that it has information for. It depends as much on the gene product and the production of a particular phenotype from this product as it does on the particular phenotype that we choose to examine, in case more than one phenotype is influenced by the same gene.'

The text states: 'What happened was that R was not completely dominant over r and this made it possible to distinguish Rr as pink from RR (red) and rr (white).'

The text mentions that a modified allele could be responsible for the production of a 'normal/less efficient enzyme'. If the enzyme is less efficient, and only one normal allele is present in a heterozygote, the overall enzyme activity might be reduced compared to a homozygote with two normal alleles, leading to an intermediate phenotype, a characteristic of incomplete dominance.

'When experiments on peas were repeated using other traits in other plants, it was found that sometimes the F1 had a phenotype that did not resemble either of the two parents and was in between the two.' This describes the intermediate phenotype of a heterozygote in incomplete dominance.

In incomplete dominance, the F2 phenotypic ratio is typically 1:2:1 (e.g., in snapdragon flower color), not 3:1. The genotypic and phenotypic ratios are the same (1:2:1) in the F2 generation for incomplete dominance.

The text states: 'Therefore, dominance is not an autonomous feature of a gene or the product that it has information for. It depends as much on the gene product and the production of a particular phenotype from this product as it does on the particular phenotype that we choose to examine, in case more than one phenotype is influenced by the same gene.'

The text explicitly states: 'A nematode Meloidegyne incognitia infects the roots of tobacco plants and causes a great reduction in yield.'