Question No:1

Assertion: Gregor Mendel, conducted hybridisation experiment on garden peas and proposed the laws of inheritance in living organism.
Reason: Mendel selected 7 true-breeding pea plant varieties.

[A] If both the assertion and the reason are true and the reason is a correct explanation of the assertion
[B] If both the assertion and reason are true but the reason is not a correct explanation of the assertion
[C] If the assertion is true but the reason is false
[D] If both the assertion and reason are false



Question No:2

Assertion: In a monohybrid cross F₁ generation indicate recessive characters.
Reason: Dominance occurs only in homozygous state.

[A] If both the assertion and the reason are true and the reason is a correct explanation of the assertion
[B] If both the assertion and reason are true but the reason is not a correct explanation of the assertion
[C] If the assertion is true but the reason is false
[D] If both the assertion and reason are false



Question No:3

Assertion: Gene which code for a pair of contrasting traits are known alleles.
Reason: Alleles are slightly different forms of the same gene.

[A] If both the assertion and the reason are true and the reason is a correct explanation of the assertion
[B] If both the assertion and reason are true but the reason is not a correct explanation of the assertion
[C] If the assertion is true but the reason is false
[D] If both the assertion and reason are false



Question No:4

Assertion: The law of dominance is used to explain the expression of only one of the parental character is a monohybrid cross in the F₁– generation.
Reason: The law of dominance explain the propportion of 3 : 1 obtained at the F₂ – generation.

[A] If both the assertion and the reason are true and the reason is a correct explanation of the assertion
[B] If both the assertion and reason are true but the reason is not a correct explanation of the assertion
[C] If the assertion is true but the reason is false
[D] If both the assertion and reason are false



Question No:5

Assertion: Deletions & insertions of base pairs of DNA, causes frame – shift mutation.
Reason: A classical example of frame -shift mutation is sickle cell anaemia.

[A] If both the assertion and the reason are true and the reason is a correct explanation of the assertion
[B] If both the assertion and reason are true but the reason is not a correct explanation of the assertion
[C] If the assertion is true but the reason is false
[D] If both the assertion and reason are false



Question No:6

Assertion: Increase in a whole set of chromosome in an organism is known as polyploidy
Reason: Failure of cytokinesis after telophase stage of cell division results in polyploidy

[A] If both the assertion and the reason are true and the reason is a correct explanation of the assertion
[B] If both the assertion and reason are true but the reason is not a correct explanation of the assertion
[C] If the assertion is true but the reason is false
[D] If both the assertion and reason are false



Question No:7

Assertion: Test cross is a back cross.
Reason: In test cross, F₁ — individual is crossed with recessive parents.

[A] If both the assertion and the reason are true and the reason is a correct explanation of the assertion
[B] If both the assertion and reason are true but the reason is not a correct explanation of the assertion
[C] If the assertion is true but the reason is false
[D] If both the assertion and reason are false



Question No:8

Assertion: Inheritance of holandric gene are always from father to son.
Reason: Holandric genes are found on Y- chromosome


[A] If both the assertion and the reason are true and the reason is a correct explanation of the assertion
[B] If both the assertion and reason are true but the reason is not a correct explanation of the assertion
[C] If the assertion is true but the reason is false
[D] If both the assertion and reason are false



Question No:9

Assertion: In humans, the gamete contributed by the male determines whether the child produced will be male or female
Reason: Sex in human is a polygenic trait depending upon a cumulative effect of some gene on X-chromosome and some on Y-chromosome.

[A] If both the assertion and the reason are true and the reason is a correct explanation of the assertion
[B] If both the assertion and reason are true but the reason is not a correct explanation of the assertion
[C] If the assertion is true but the reason is false
[D] If both the assertion and reason are false



Question No:10

Assertion: In birds, the chromosomes composition of the sperm determines the sex.
Reason: Male birds are heterogametic.

[A] If both the assertion and the reason are true and the reason is a correct explanation of the assertion
[B] If both the assertion and reason are true but the reason is not a correct explanation of the assertion
[C] If the assertion is true but the reason is false
[D] If both the assertion and reason are false



Question No:11

In Antirrhinum two plants with pink flowers were hybridized. The F₁ plants produced red, pink and white flowers in the proportion of 1 red, 2 pink and 1 white. What could be the genotype of the two plants used for hybridization Red flower colour is determined by RR, and white by rr genes.

[A] rrrr
[B] RR
[C] Rr
[D] rr



Question No:12

A cross in which an organism showing a dominant phenotype is crossed with the recessive parent in order to know its genotype is called

[A] Monohybrid cross
[B] Back cross
[C] Test cross
[D] Dihybrid cross



Question No:13

ABO blood grouping is controlled by gene I which has three alleles and show co-dominance. There are six genotypes. How many phenotypes in all are possible?

[A] Six
[B] Three
[C] Four
[D] Five



Question No:14

The fruit fly Drosophila melanogaster was found to be very suitable for experimental verification of chromosomal theory of inheritance by Morgan and his colleagues because:

[A] It reproduces parthenogenetically
[B] A single mating produces two young flic
[C] Smaller female is easily recognisable from larger male
[D] It completes life cycle in about two weeks



Question No:15

The fruit fly, drosophila melanogaster was found to be very suitable for experimental verification of chromosomal theory of inheritance by Morgan and his colleagues because:

[A] It reproduces parthenogenetically
[B] A single mating produces two young flies
[C] Smaller female is easily recognisable from larger male
[D] It completes life cycle in about two weeks