CBSE 12 Biology Question Paper-2025 Set-2

Some flowers are unisexual, this property of unisexuality of flowers prevents which kind of pollination?

Given below is the schematic representation of spermatogenesis in human males: Choose the option that shows the correct labelling of 'I', 'II', 'III' and 'IV' in the given diagram.

Which of the following options shows the correct sequence of development of the given plants? (i) Fern (ii) Ginkgo (iii) Zosterophyllum (iv) Nietels Choose the correct option.

The number of autosomes present in a human secondary spermatocyte

Given below is a diagram of T.S. of a monocot seed with parts I, II & III labelled: Choose the option where parts I, II and III are identified correctly.

Given below is a heterogeneous RNA formed during Eukaryotic transcription: How many introns and exons respectively are present in the hnRNA?

If the Meselson and Stahl experiment is continued for 80 minutes (third generation), what will be the ratio of DNA with N¹⁵/N¹⁵: N¹⁵/N¹⁴: N¹⁴/N¹⁴ in the culture?

A child with blood group A has father with blood group B and the mother with blood group AB. Choose the option that gives the correct genotypes of father, mother and the child :

In a pedigree analysis chart ☐ ☐ represents:

The number of autosomes present in a human secondary spermatocyte:

Given below is a diagram of T.S. of a monocot seed with parts I, II & III labelled: [Image of a monocot seed diagram] Choose the option where parts I, II and III are identified correctly.

Given below is a heterogeneous RNA formed during Eukaryotic transcription: How many introns and exons respectively are present in the hnRNA?

If the Meselson and Stahl experiment is continued for 80 minutes (third generation), what will be the ratio of DNA with N¹⁵/N¹⁵: N¹⁵/N¹⁴: N¹⁴/N¹⁴ in the culture?

A child with blood group A has father with blood group B and the mother with blood group AB. Choose the option that gives the correct genotypes of father, mother and the child :

In a pedigree analysis chart ☐ ☐ represents:

In a pedigree analysis chart ☐ ☐ represents:

The name of the scientist who proposed the principle that the flow of genetic information in molecular biology is unidirectional is:

Which of the following characteristics correctly expresses the mechanism of sex determination in honeybees? (i) Zygote is formed by the fusion of a sperm and an ovum (male). (ii) The number of chromosomes in a male (drone) is half the number of chromosomes in a female honeybee. (iii) Female honeybees are diploid with 32 chromosomes. (iv) Male honeybees have fathers and can produce male progeny. Choose the correct option: