CBSE Class 12 Biology 2025 Sample Paper Solved Set 1

SECTION A

Q. No. 1 to 12 are multiple choice questions. Only one of the choices is correct. Select and write the correct choice as well as the answer to these questions.

1 Which among the following came into India as a contaminant with imported wheat, has become ubiquitous in occurrence and causes pollen allergy
(a) Lantana
(b) Eicchhornia
(c) Parthenium
(d) Chenopodium

Answer : c

2. Ectopic pregnancies are referred as-
(a) Pregnancies with genetic abnormalities
(b) Implantation of defective embryo in the uterus
(c) Implantation of embryo at site other than the uterus
(d) Pregnancies terminated due to hormonal imbalance

Answer : c

3 Which of the following statements indicates parallelism in genes and chromosomes?
(i) They occur in pairs
(ii) They segregate during gamete formation
(iii) They show linkage
(iv) Independent pairs segregate independently
(a) (i) and (iii)
(b) (ii) and (iii)
(c) (i), (ii) and (iii)
(d) (i), (ii) and (iv)

Answer : d

4 In E.coli, the lac operon gets switched on when
a) lactose is present and it binds to the repressor
b) repressor binds to operator
c) RNA polymerase binds to the operator
d) lactose is present and it binds to RNA polymerase

Answer : a

5 The separated bands of desired DNA are cut out from the agarose gel and extracted from gel piece is known as
a) southern blotting
b) western blotting
c) gel electrophoresis
d) elution

Answer : d

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