3 – Life Processes in Living Organisms | Part 1 | Science II | Class 10

The blog presents the short Questions and Answers of the Chapter 3, Life Processes in Living OrganismsPart 2, from Science Part II of Class 10 from Maharashtra State Board. These can be very useful for students preparing for SSC Board exams as well as competitive exams, as it includes the objective type basic concepts & fundamentals.

1. Reproduction does not help the organism to remain alive, then why is it so important ?

Ans. Reproduction does not help the organism to remain alive but it helps to maintain the continuity of the species of that organism. Hence it is important.

2. Define reproduction.

Ans. Formation of new organism of same species by earlier existing organism is called as reproduction.

3. What are the methods of reproduction in living organisms ?

Ans. In living organisms, reproduction occurs mainly by two methods :
(a) asexual reproduction
(b) sexual reproduction

4. Define asexual reproduction.

Ans. Process of formation of new organism by an organism of same species without involvement of gametes is called as asexual reproduction.

5. Why asexual reproduction produces exact genetic similar new organism ?

Ans. As asexual reproduction involves a single parent and does not involve union of two different gametes, the new organism has exact genetic similarity with the reproducing organism.

6. What is the type of cell division in asexual reproduction ?

Ans. Asexual reproduction is uniparental reproduction, and hence it occurs by mitotic cell division.

7. State a drawback and an advantage of asexual reproduction method ?

Ans. Absence of genetic recombination is a drawback whereas fast process is advance of asexual reproduction method.

8. What are the methods of asexual reproduction in unicellular organisms ?

Ans. Asexual reproduction in unicellular organisms are by the following three methods : (a) Binary Fission
(b) Multiple Fission
(c) Budding

9. What are three methods of binary fission in Unicellular organisms?

Ans. The three methods of binary fission in unicellular organisms are :
(a) Simple binary fission (Amoeba)
(b) Transverse binary fission (Paramecium)
(c) Longitudinal binary fission (Euglena)

10. When is binary fission performed by living organisms ?

Ans. Binary fission is usually performed by living organisms during favourable conditions i.e. availability of abundant food material.

11. What is a Cyst, formed in multiple fission ?

Ans. Whenever there is lack of food or any other type of adverse condition, Amoeba stops the formation of pseudopodia and thereby its movements. It becomes rounded and forms protective covering around plasma membrane.
Such encysted Amoeba or any other protist is called as Cyst.

12. What are methods of asexual reproduction in Multicellular organisms?

Ans. Asexual reproduction in Multicellular organisms occurs by the following methods:
(a) Fragmentation (Spirogyra)
(b) Regeneration (Planaria)
(c) Budding (Hydra)
(d) Vegetative Propagation (Bryophyllum)
(e) Spore Formation (Mucor)

13. What is essential for sexual reproduction to occur ?

Ans. Sexual reproduction always occurs with the help of two germ cells i.e.:
(a) male gamete
(b) female gamete

14. What are the two important steps in sexual reproduction ?

Ans. Two main processes occur in the sexual reproduction :
(a) Gamete formation: Gametes are formed by the meiosis. In meiosis, chromosome number is reduced to half; hence haploid gametes are
formed.
(b) Fertilization: A diploid zygote is formed in this process by union of haploid male and female gametes. The zygote divides by mitosis and embryo is formed. The embryo develops to form new individual.

15. Why the new individual formed in sexual reproduction have recombined genes of both the parents?

Ans. In sexual reproduction, the fusion of male gamete of male parent and female gamete of female parent occurs. Due to this, new individual always has the recombined genes of both the parents.

16. Why does the new individual formed in sexual reproduction show similarity and diversity with the parents ?

Ans. In sexual reproduction the fusion of male gamete and female gamete of parents occurs. Due to this, new individual always has the recombined genes of both the parents. Therefore the new individual formed shows
similarities with the parents for some characters and has some characters different than both parents.

17. What is the use of genetic diversity ?

Ans. Genetic variation helps the organisms to adjust with the changing environment and thereby to maintain their existence. Due to this, plants and animals can save themselves from being extinct.

18. What is the structural unit of sexual reproduction in plants ?

Ans. Flower is structural unit of sexual reproduction in plants.

19. Name the four floral whrols.

Ans. The four floral whorls are : calyx, corolla, androecium and gynaecium arranged in sequence from outside to inside.

20. Name the essential whrols and function they perform.

Ans. The androecium and gynoecium are called essential whorls, because they perform the function of reproduction.

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