Illustrative questions Important for ISC Biology 2021-22 (Reproduction in Organisms)

 

Illustrative questions Important for ISC Biology 2021-22 (Reproduction in Organisms)

 

Q1. Define reparative regeneration with examples.

Answer: - This is a process of replacement of lost parts or repairing of damaged body parts. For example, regeneration of limb in Salamander, lost tail in lizard and healing of wounds in humans.

Q2. What is the significance of cyst formation in Amoeba?

Answer: - Cyst is a thick-walled structure. It protects Amoeba from adverse environmental conditions and helps in its dispersal. Under favourable conditions, its nucleus gets surrounded by cytoplasm and forms a new Amoeba.

Q3. What is the practical significance of vegetative propagation?

Answer: - By utilizing the techniques of vegetative propagation, we can (i) obtain new plants in a short duration and (ii) we can get plants having good qualities of two different varieties.

Q4. Why is sexual reproduction known as germinal reproduction?

Answer: - As the sexual reproduction involves fusion of gametes, these gametes are formed from the germ cells of gonads. Hence, sexual reproduction is called germinal reproduction.

Q5. Define hermaphrodite organisms.

Answer: - The organisms which have both male and female gonads are called hermaphrodites, e.g., Earthworm among animals and Mustard flower among plants.

Q6. What is that phenomenon in which larva develops gonads and starts reproducing without undergoing metamorphosis? Give some examples.

Answer: - this phenomenon is known as paedogenesis. It is found in Axolotl larva of Ambystoma mexicanum (Tiger Salamander), Nectus (Mud Puppy), and Triturus.

Q7. What is another term used for regeneration?

Answer: - Neogenesis.

Q8. Name the method of asexual reproduction found in bacteria, protozoans and unicellular algae.

Answer: - Binary fission.

Q9. What is a spore? Why is multiple fission in Amoeba called sporulation?

Answer: - Spores are haploid asexual reproductive bodies that develop in haploid organisms under favorable conditions.

Products of multiple fission in Amoeba are pseudopodispores and these are formed in Amoeba which has undergone encystment.

Q10. What is the difference between pollination and fertilization?

Answer: - Pollination is simply the transfer of pollen from anther to the stigma of a pistil. It precedes fertilization. Fertilization is the fusion of a male nucleus with a female nucleus so as to form a diploid zygote nucleus. If pollination does not take place, fertilization fails.