In a monohybrid cross of plants with red and white-flowered plants, Mendel got only red-flowered plants. On self-pollinating, these F 1 plants got both red and white-flowered plants in 3:1 ratio. Explain the basis of using RR and rr symbols to represent the genotype of plants of the parental generation.

Upon crossing homozygous dominant and homozygous recessive plants, a dominant allele is expressed in the F 1 generation. Since all the F 1 plants have a red-coloured flower, we can say that the red colour is dominant and the white colour is recessive. When F 1 plants were self crossed, the alleles got segregated during the gamete formation, and the phenotypic ratio of 3:1 (red: white) is obtained in the F 2 generation.

E M B I B E

NCERT Exemplar Biology - Class 12>Chapter 5 - Principle of Inheritance and Variation>VERY SHORT ANSWER TYPE QUESTIONS>Q 5

HARD

12th CBSE

IMPORTANT

Earn 100

The pedigree chart given below shows a particular trait which is absent in parents but present in the next generation irrespective of sexes. Draw your conclusion on the basis of the pedigree.

Important Questions on Principle of Inheritance and Variation

HARD

12th CBSE

IMPORTANT

NCERT Exemplar Biology - Class 12>Chapter 5 - Principle of Inheritance and Variation>VERY SHORT ANSWER TYPE QUESTIONS>Q 6

In order to obtain the F₁ generation, Mendel pollinated a pure-breeding tall plant with a pure breeding dwarf plant. But for getting the F₂ generation, he simply self-pollinated the tall F₁ plants. Why?

HARD

12th CBSE

IMPORTANT

NCERT Exemplar Biology - Class 12>Chapter 5 - Principle of Inheritance and Variation>VERY SHORT ANSWER TYPE QUESTIONS>Q 7

"Genes contain the information that is required to express a particular trait." Explain.

MEDIUM

12th CBSE

IMPORTANT

NCERT Exemplar Biology - Class 12>Chapter 5 - Principle of Inheritance and Variation>VERY SHORT ANSWER TYPE QUESTIONS>Q 8

How are alleles of particular gene differ from each other? Explain its significance.

MEDIUM

12th CBSE

IMPORTANT

NCERT Exemplar Biology - Class 12>Chapter 5 - Principle of Inheritance and Variation>VERY SHORT ANSWER TYPE QUESTIONS>Q 9

In a monohybrid cross of plants with red and white-flowered plants, Mendel got only red-flowered plants. On self-pollinating, these F₁ plants got both red and white-flowered plants in 3:1 ratio. Explain the basis of using RR and rr symbols to represent the genotype of plants of the parental generation.

HARD

12th CBSE

IMPORTANT

NCERT Exemplar Biology - Class 12>Chapter 5 - Principle of Inheritance and Variation>VERY SHORT ANSWER TYPE QUESTIONS>Q 10

For the expression of traits, genes provide only the potentiality and the environment provides the opportunity. Comment on the veracity of the statement.

HARD

12th CBSE

IMPORTANT

NCERT Exemplar Biology - Class 12>Chapter 5 - Principle of Inheritance and Variation>VERY SHORT ANSWER TYPE QUESTIONS>Q 11

A, B, D are three independently assorting genes with their recessive alleles a, b, d, respectively. A cross was made between individuals of Aa bb DD genotype with aa bb dd. Find out the type of genotypes of the offspring produced.

HARD

12th CBSE

IMPORTANT

NCERT Exemplar Biology - Class 12>Chapter 5 - Principle of Inheritance and Variation>VERY SHORT ANSWER TYPE QUESTIONS>Q 12

In our society, a woman is often blamed for not bearing a male child. Do you think it is right? Justify.

MEDIUM

12th CBSE

IMPORTANT

NCERT Exemplar Biology - Class 12>Chapter 5 - Principle of Inheritance and Variation>VERY SHORT ANSWER TYPE QUESTIONS>Q 13

Discuss the genetic basis of wrinkled phenotype of pea seed.