20 Questions with Answers and Explanations on “Reproduction in Organisms” for Biology Students:
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Smock > Flashcards > Week 5: Mitosis/Meiosis …”/>Q. 1. Name the period from birth to the natural death of an organism.
Ans. Life span.
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Q. 2. Which types of organisms are immortal? Multicellular or single cellular organisms?
Ans. Single cellular organisms.
Q. 3. Why is reproduction essential for organisms?
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Ans. Reproduction is essential for organism because it enables the continuity of the species, generation after generation.
Q. 4. Why is the offspring formed by asexual reproduction referred to as clone?
Ans. It is referred to as ‘clone’ because the offspring is morphologically and genetically identical to the parent.
Q. 5. Mention the mode of reproduction in protists and monerans.
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Ans. Cell division.
Q. 6. Name the vegetative propagule used for commercial propagation of banana and ginger.
Ans. Rhizome.
Q. 7. Which simple plants during favourable conditions reproduced by asexual mode but during unfavourable conditions shift to sexual mode of reproduction?
Ans. 1. Algae
2. Fungi
Q. 8. Mention the flowering period in—
1. Bamboo
2. Strobilanthus kunthiana (neela kuranji)
Ans. 1. Bamboo— 50-100 years i.e. once in its life time.
2. Strobilanthus kunthiana—12 years.
Q. 9. Some animals are called as seasonal breeders. Why?
Ans. Many mammals that live in natural conditions (wild) exhibit cyclic changes in reproduction, only during favourable seasons in their reproductive phase, hence they are seasonal breeders.
Q. 10. Give two examples of each:
(a) Seasonal breeders
(b) Continuous breeders.
Ans. (a) Seasonal breeders—cows, rats,
(b) Continuous breeders—human, monkey.
Q. 11. Mention the stages of sexual reproduction.
Ans. 1. Prefertilisation,
2. Fertilization,
3. Post-fertilization.
Q. 12. What are homogamates or isogamates?
Ans. The gametes (male & female) that are so similar in appearance that it is difficult to differentiate between them are called as homogamates/isogamates.
Q. 13. Give one example to each—
1. Organisms producing homogamate
2. Organism producing heterogamete.
Ans. 1. Homogamate – Cladophora (Algae)
2. Heterogamate—Human
Q. 14. Human being is a diploid organism. What is the number of chromosomes present in its sperm cell?
Ans. 23 (2n).
Q. 15. The meiocyte cell of fruit fly (Drosophila) has 8 chromosomes. What will be the number of chromosome in the egg cell?
Ans. 4 (n).
Q. 16. The gamete of rice plant has 12 (n) chromosome number? What must be the chromosome number in a meiocyte?
Ans. 24 (2n).
Q. 17. Name the medium required for the gametes to transfer in case of algae, bryophytes and pteridophytes.
Ans. Water.
Q. 18. What is bisexual flower?
Ans. Flower that has both male and female reproductive structures is called bisexual flower.
Q. 19. What is zygotic meiosis?
Ans. The meiosis division in zygote produces haploid spores to form haploid individuals. It takes place in haplontic life-cycle and such a division is called zygotic meiosis.
Q. 20. Give a suitable reason why reptiles and birds give/lay shelled eggs and mammals give eggs without shell?
Ans. In first case, the eggs need protection from environment and care, whereas, in second case, the eggs are produced inside the animal body; hence, they need no protection from environment.