To determine the genotype of an organism showing a dominant phenotype, such as a tall F2 plant, Mendel crossed it with the recessive parent, a cross he called a _______.
To determine the genotype of a tall plant at F2, Mendel crossed it with a dwarf plant, which he called a test cross.
Question 262 of 519
📘 CLASS XII
Mendel's First Law, the Law of _______, is used to explain the expression of only one of the parental characters in a monohybrid cross in the F1 generation.
The First Law or Law of Dominance is used to explain the expression of only one of the parental characters in a monohybrid cross in the F1.
Question 263 of 519
📘 CLASS XII
The Law of Segregation is based on the fact that the alleles do not show any _______ and that both characters are recovered as such in the F2 generation.
The Law of Segregation is based on the fact that the alleles do not show any blending and that both the characters are recovered as such in the F2 generation.
Question 264 of 519
📘 CLASS XII
In the case of incomplete dominance in Snapdragon, the F2 phenotypic ratio (1 Red : 2 Pink : 1 White) is identical to the _______ ratio (1:2:1).
In incomplete dominance, the genotype ratios (1:2:1) were exactly as expected in a Mendelian monohybrid cross, but the phenotype ratios had changed from the 3:1 ratio.
Question 265 of 519
📘 CLASS XII
The unmodified (functioning) allele that produces the enzyme required for a substrate transformation is the dominant allele, and the modified allele, which is non-functional or produces no enzyme, is generally the _______ allele.
The unmodified (functioning) allele, which represents the original phenotype is the dominant allele and the modified allele is generally the recessive allele.
Question 266 of 519
📘 CLASS XII
In human ABO blood grouping, when alleles IA and IB are present together, they both express their own types of sugars, a phenomenon called _______.
When IA and IB are present together they both express their own types of sugars, which is because of co-dominance.
Question 267 of 519
📘 CLASS XII
The ABO blood grouping system in humans provides a good example of _______ because there are three alleles (IA, IB, and i) governing the same character in the population.
The example of ABO blood grouping provides a good example of multiple alleles, where there are more than two, i.e., three alleles, governing the same character.
Question 268 of 519
📘 CLASS XII
If starch grain size is considered as the phenotype in pea seeds (controlled by alleles B and b), the heterozygotes (Bb) produce intermediate size grains, indicating _______ dominance.
If starch grain size is considered as the phenotype, the alleles show incomplete dominance because the starch grains produced are of intermediate size in Bb seeds.
Question 269 of 519
📘 CLASS XII
Mendel's Law of Independent Assortment states that when two pairs of traits are combined in a hybrid, segregation of one pair of characters is _______ of the other pair of characters.
The Law of Independent Assortment states that segregation of one pair of characters is independent of the other pair of characters.
Question 270 of 519
📘 CLASS XII
Mendel's work remained unrecognised until 1900 partly because his approach of using _______ to explain biological phenomena was totally new and unacceptable to many biologists of his time.
Mendel's approach of using mathematics to explain biological phenomena was totally new and unacceptable to many of the biologists of his time.
