CBSE Class 8 Science Animal Reproduction Chapter Notes. Learning the important concepts is very important for every student to get better marks in examinations. The concepts should be clear which will help in faster learning. The attached concepts made as per NCERT and CBSE pattern will help the student to understand the chapter and score better marks in the examinations.
REPRODUCTION IN ANIMAL
The process by which an organism produce offsprings is known as reproduction.
The process by which living beings produce offspring of their own kind is called reproduction.
• Offsprings are genetically similar to their parents.
• Reproduction is necessary for the existence and continuity of species in universe.
Reproduction is of two types : (i) Asexual Reproduction (ii) Sexual Reproduction
• Production of offsprings by a single parent without the formation and fusion of gametes is called asexual reproduction.
• It is a primitive type of reproduction.
• In this type of reproduction offspring is produced by a cell or any vegetative organ of an organism.
• In this type of reproduction offsprings are genetically identical to their parents.
Reproduction in Hydra :
• In this method an outgrowth (bud) is formed on the parent organism.
• The bud gradually grows in size and gets detached from the parent.
• Detached bud develops into an adult organism, similar to the parent
Other example :- Yeast
Reproduction resulting from the fusion of male and female gametes is called sexual reproduction.
The type of reproduction in which fusion of male & female gamete occur is called sexual reproduction.
Important features of sexual reproduction are given below :
(i) It involves two different parents i.e. one male and one female.
(ii) Each parent produces gametes.
(iii) Male gametes are called sperms while female gametes are called ova or eggs.
(iv) The fusion of male and female gametes is called fertilization. It results in to the formation of a single diploid cell zygote.
(v) The zygote undergoes repeated mitotic divisions to form embryo which differentiate to form full organism.
(vi) The organisms produced in this type of reproduction are genetically different from both the parents and can resemble in certain features with parents
Types of animals on the basis of presence of sex organs :
(a) Unisexual Animals : Those animals in which male and female sexes remain separate e.g. Human beings, Cow, Cat, Dog.
(b) Bisexual Animals : • Those animals in which male and female sex organs are present in single body are called bisexual or
hermaphrodite e.g. Earthworm, Taenia solium, Leech
HUMAN REPRODUCTIVE SYSTEM
Male Reproductive organs : The male reproductive system of humans consists of the following organs.
(1) Testes (2) Vas deferens (3) Urethra (4) Penis
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