Page 38 - EM BIOLOGY NOTES 10TH CLASS PSR DIGITAL BOOKS

6. REPRODUCTION
(THE GENERATING SYSTEM)

Lesson related 1, 2, 4 marks
 Reproduction :-
Activities Question and
 The ability of an organism to produce a new generation of videos Answers PDF
individuals of the same species is called reproduction. pl.scan QR pl.scan QR
 Reproduction is necessary for perpetuation and continuation of life.
 Reproduction in a given species is to replace the number of the species that die and also to
allow an increase in the total number of the species.
 There are two modes by which animals reproduce. These are
(i) Sexual reproduction (ii) Asexual reproduction
 In Asexual reproduction, new individuals are produced without the fusion of gametes.
 In Sexual reproduction, fusion of gamates is required to form a new individual.

Sexual Reproduction Asexual Reproduction
1. Involves one (or) two organisms. 1. Involves a single organism.
2. Male and female gamates are produced. 2. Gamates are not produced.
3. Involves fusion of gamates. 3. No fusion of gamates.
4. Required mitotic and meotic divisions. 4. Required mitotic divisions only.
5. Chance of genetic variations is more. 5. No chance for genetic variaions.
6. Offsprings may have characters of both 6. Offsprings are identical to the parent.
the parents and some characters which
are not present in either of the parents.
7. Highly useful for natural selection is 7. Not very useful for natural selection
evolution of species. in evolution of species.

Asexual Reproduction :- Organisms can reproduce asexually in many ways. They are :
1. Fission 2. Budding 3. Fragmentation 4. Spore formation/sporulation
5. Regeneration 6. Vegetative propagation
1. Fission :- Single celled organisms, such as Bacteria, Amoeba and Paramoecium, repro-
duce by splitting into two or more offsprings.
 They split into two by binary fission. When more cells are formed it is called multiple
fission.

2. Budding :- A growth on the body as a bud that grows to form nearly identical copy of the
parent.
 When the bud totally grows then it saparates from the parent and survives independently.
Ex :- Yeast, Hydra.

3. Fragmentation :- Fragmentation is common mode of reproduction in algae and fungi.
 In this process, a detached fragment of the fungal hyphae gives rise to a new individual
under suitable conditions.

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