Biology MCQ Practice 30 — Science Foundation Course for Class 11 & 12

1. The theory of evolution by natural selection was proposed by:

(a) Lamarck (b) Darwin (c) Mendel (d) Watson and Crick

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Correct Answer: (b) Darwin

Explanation: Charles Darwin proposed the theory of evolution by natural selection in "Origin of Species".

2. The enzyme used in PCR to amplify DNA is:

(a) DNA ligase (b) Taq polymerase (c) Helicase (d) Restriction enzyme

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Correct Answer: (b) Taq polymerase

Explanation:
Taq polymerase is thermostable and used in PCR

3. The hormone responsible for uterine contraction during childbirth is:

(a) Prolactin (b) Oxytocin (c) Estrogen (d) Progesterone

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Correct Answer: (b) Oxytocin

Explanation:
Oxytocin causes uterine contractions (parturition)

4. The tissue that stores water and nutrients in plants is:

(a) Aerenchyma (b) Parenchyma (c) Collenchyma (d) Sclerenchyma

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Correct Answer: (b) Parenchyma

Explanation:
Parenchyma is involved in storage and photosynthesis

5. The maintenance of stable internal environment is known as:

(a) Homeostasis (b) Adaptation (c) Evolution (d) Mutation

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Correct Answer: (a) Homeostasis

Explanation:
Homeostasis maintains internal balance

6. The functional unit of the nervous system is:

(a) Nephron (b) Neuron (c) Alveolus (d) Sarcomere

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Correct Answer: (b) Neuron

Explanation:
Neuron transmits nerve impulses

7. The pigment responsible for skin, hair and eye colour is:

(a) Haemoglobin (b) Melanin (c) Chlorophyll (d) Carotene

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Correct Answer: (b) Melanin

Explanation:
Melanin is produced by melanocytes

8. The largest part of the human brain is:

(a) Cerebellum (b) Cerebrum (c) Medulla oblongata (d) Hypothalamus

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Correct Answer: (b) Cerebrum

Explanation:
Cerebrum controls voluntary actions and higher mental functions

9. The fusion of male and female gametes is known as:

(a) Pollination (b) Fertilisation (c) Implantation (d) Gestation

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Correct Answer: (b) Fertilisation

Explanation:
Fertilisation results in zygote formation

10. The basic unit of muscle contraction is:

(a) Neuron (b) Nephron (c) Alveolus (d) Sarcomere

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Correct Answer: (d) Sarcomere

Explanation:
Sarcomere is the contractile unit of striated muscle