Question Bank — How do Organisms Reproduce?

Section A — MCQs (10 questions, 1 mark each)

1. The basic event in reproduction involving creation of a DNA copy is accompanied by:
   (a) formation of an additional cellular apparatus
   (b) immediate death of the parent cell
   (c) complete elimination of all variations
   (d) direct transfer of DNA to another organism

2. In Leishmania, binary fission occurs in a definite orientation because of:
   (a) presence of a whip-like structure at one end
   (b) multiple daughter cells forming simultaneously
   (c) budding from the parent body
   (d) fragmentation into smaller pieces

3. Which of the following is an advantage of vegetative propagation?
   (a) It introduces high genetic variation in offspring
   (b) Plants can bear flowers and fruits earlier than those from seeds
   (c) It requires two parents for reproduction
   (d) It always produces disease-resistant plants

4. The transfer of pollen from the anther of one flower to the stigma of another flower of the same species is called:
   (a) self-pollination
   (b) cross-pollination
   (c) fertilisation
   (d) germination

5. In human males, the testes are located outside the abdominal cavity in the scrotum because:
   (a) sperm formation requires a lower temperature
   (b) it helps in production of more testosterone
   (c) it prevents entry of urine into the reproductive tract
   (d) it allows direct release of sperms into the vagina

6. The disc-like tissue embedded in the uterine wall that provides large surface area for exchange of nutrients and oxygen between mother and embryo is:
   (a) fallopian tube
   (b) placenta
   (c) cervix
   (d) vas deferens

7. If the egg is not fertilised, the thickened uterine lining breaks down and is discharged through the vagina as blood and mucus. This process is known as:
   (a) ovulation
   (b) menstruation
   (c) implantation
   (d) fertilisation

8. The function of the seminal vesicles and prostate gland is to:
   (a) produce eggs
   (b) add secretions that make sperms mobile and provide nutrition
   (c) block the fallopian tubes
   (d) form the placenta

Assertion-Reason Questions

9. Assertion (A): Variations are useful for the survival of species over time.
   Reason (R): Niches in the ecosystem can change due to reasons beyond the control of organisms, such as temperature rise.
   (a) Both A and R are true and R is the correct explanation of A.
   (b) Both A and R are true but R is not the correct explanation of A.
   (c) A is true but R is false.
   (d) A is false but R is true.

10. Assertion (A): DNA copying cannot be absolutely accurate.
    Reason (R): No biochemical reaction is completely reliable, leading to variations during reproduction.
    (a) Both A and R are true and R is the correct explanation of A.
    (b) Both A and R are true but R is not the correct explanation of A.
    (c) A is true but R is false.
    (d) A is false but R is true.

Section B — Very Short Answer (6 questions, 2 marks each)

1. Differentiate between binary fission and multiple fission with one example of each.
2. State two advantages of spore formation for organisms like Rhizopus.
3. Why do multicellular organisms with complex body organisation require specialised cells for reproduction instead of simple cell-by-cell division?
4. What is the role of the style and stigma in a flower during sexual reproduction?
5. Name the hormones secreted by testes and ovaries and state one function of each.
6. How does the use of condoms help in preventing sexually transmitted diseases?

Section C — Short Answer (5 questions, 3 marks each)

1. Explain the process of regeneration in Planaria. Why is regeneration not considered the same as reproduction?
2. Describe how a seed is formed after fertilisation in flowering plants. What happens to other floral parts?
3. List three changes observed in boys and three changes observed in girls at the time of puberty.
4. Draw a neat labelled diagram of the human male reproductive system and label any four parts.
5. Why is the lining of the uterus thickened every month? What happens if fertilisation does not occur?

Section D — Long Answer (3 questions, 5 marks each)

1. Describe with a labelled diagram the process of binary fission in Amoeba. How does it differ from binary fission in Leishmania? (Diagram-based)
2. Explain the structure and function of the female reproductive system in humans. Describe the role of the placenta in nourishing the embryo. (Include labelled diagram description of the system)
3. What are the different methods of contraception? Explain any four methods with their mode of action. Why is maintaining a balanced sex ratio important for society?

Section E — Case/Source-Based (2 questions, 4 marks each)

Case 1: A student performs an activity by dissolving sugar in water, adding yeast granules, and observing the culture under a microscope after keeping it in a warm place. Another slice of bread is kept in a cool, moist, dark place and observed with a magnifying glass for a week.

(a) What structures are observed growing on the bread slice after a few days?
(b) How do these structures help in reproduction of the organism?
(c) Why does yeast show budding while the bread mould shows spore formation?
(d) State one advantage of reproducing through spores for such organisms.

Case 2: In tissue culture, a small piece of tissue is removed from the growing tip of a plant and placed in an artificial medium containing nutrients and hormones. The cells divide to form a callus, which is then transferred to another medium for differentiation into plantlets.

(a) Name the technique described and one plant for which it is commonly used.
(b) Why is this method useful for producing disease-free plants?
(c) How does this method ensure that all new plants have characteristics similar to the parent?
(d) Give one situation where this technique would be preferred over traditional vegetative propagation.

Section F — HOTS and Application (4 questions, 3 marks each)

1. Predict-and-justify: What would happen if DNA copying were 100% accurate with no variations at all during reproduction? Justify your answer using the concept of changing environmental niches.
2. Analyse an unexpected observation: In an experiment, a potato is cut into pieces with and without buds and placed on moist cotton. After a few days, only pieces with buds produce shoots and roots. Analyse what this observation indicates about vegetative propagation.
3. Apply to unfamiliar situation: A farmer wants to grow disease-free banana plants quickly on a large scale even though the variety does not produce seeds. Which method from the chapter should be used and why? Explain the process briefly.
4. Compare two situations: Compare reproduction by budding in Hydra with fragmentation in Spirogyra. Justify which method allows slightly more variation and why, based on the mechanism involved.