1. The production of new individual form the parents is known as reproduction.
Reproduction is very important as it ensures the continuation of similar kinds of individuals, generation after generation. If this process do not exist, the generation of living beings will be vanished from the earth.
2. In human beings, sexual reproduction occurs in which reproduction results from the fusion of male and female gametes. Male produce sperms in testes and female produce ovum in ovary. Male release their sperms in female reproductive organ during copulation, called vagina from where the sperms move towards the fallopian tube. Female release one ovum every month in the middle of menstruation cycle which travels towards the fallopian tube. The fusion of male and female gametes takes place in fallopian tube. The fusion of male and female gametes is called fertilisation.
3. (a) (i) in female body.
(b) (ii) metamorphosis.
(c) (ii) one.
(a) (F) (e) (T) (i) (T)
(b) (T) (f) (F) (j) (F)
(c) (T) (g) (T)
(d) (T) (h) (T)
5. When fertilisation takes place, the nuclei of the sperm and the egg fuse to form a single nucleus, which results in the formation of a fertilized egg or zygote.
Zygote now begins to develop into an embryo. The embryo continues to develop in the uterus and produces body parts such as hands, legs, head, eyes etc. the stage of the embryo in which all the body parts are identified is called foetus.
6. The type of reproduction in which only a single parent is involved is called asexual reproduction.
Asexual reproduction takes place in very small animals like Hydra and microscopic organism like Amoeba.
Budding-New individual develops as outgrowths from a single parent. In hydra a small bulges called buds develops into new individuals.
Binnary fission-The body of unicellular organisms like amoeba divides into two equal parts and each parts develops as new individual.
7. The embryo gets embedded in the wall of the uterus for further development.
8. The drastic change which takes place during the development of an animal is called metamorphosis. The animals that undergoes metamorphosis are
a. Silkworm (egg –> caterpillar –> pupa –>adult)
b. Frog ( egg –> tadpole –> adult)
9. Internal fertilisation
(i) The fertilisation takes place inside the female body.
(ii) Example-human beings, hen, dog etc.
(i) The fertilisation takes place outside the body of female.
(ii) Example-frog, fish etc.