1)Explain the importance of reproduction in organisms.
ANSWER:-Reproduction helps to carry on their generation. If reproduction does not
take place, no living being will survive on the earth. Had the process of
reproduction not been there then all the plants and animals would have become
extinct. Secondly, special characters of an organism are carried over to its
next generation through reproduction only.
2) Describe the process of fertilization in human beings.
ANSWER:-There is sexual reproduction in human beings. Male reproductive
organs produce sperms (male gametes) while the female gametes produce ova
(female gametes). The sperms are ejected inside female bodies where they fuse
with ovum and forms zygote (called internal fertilization). The single celled
zygote begins to develop into an embryo which attaches to the female uterus
wall. The embryo further multiples into many cells and develops further into a
small baby called foetus.
3) Choose the most appropriate answer:
(a) Internal fertilization occurs
(ii) outside female body.
ANSWER: (i) in female body.
(b) A tadpole develops into an adult frog by the process of
(i) fertilization. (ii) metamorphosis. (iii) embedding. (iv)
ANSWER:- (ii) metamorphosis.
c)The number of nuclei present in a zygote is
(i) none. (ii) one. (iii) two. (iv) four.
4) Indicate whether the following statements are True (T) or
(a) Oviparous animals give birth to young ones. ( )
(b) Each sperm is a single cell.( )
(c) External fertilization takes place in frogs. ( )
(e) Egg laid after fertilization up of a single cell. ( )
(f) Amoeba reproduces by budding. ( )
(g) Fertilization is necessary even in asexual reproduction.( )
(h) Binary fission is a method of asexual reproduction. ( )
(i) A zygote is formed as a result of fertilization. ( )
(j) An embryo is made up of a single cell. ( )
5)Give two difference between a zygote and a foetus.
after the body
parts of a
fusion of mature
Zygote is single. Embryo is
cellular. multi cellular.
6) Define asexual reproduction. Describe two methods of asexual
reproduction in animals.
ANSWER: – Asexual reproduction is that type of reproduction in which only
single parent is involved. Asexual reproduction takes place by different
methods like Budding, Binary fission etc.
→ Budding: This type of reproduction takes place in Hydra
and Bacteria. A part of the organism starts
bulging out. Slowly it grows and develops into a separate individual.
→ Binary fission : In this type
of reproduction, a single organism gets divided into
two. This type of reproduction takes place in
7)In which female reproductive organ does the embryo get
ANSWER:- The embryo gets embedded in the wall of the uterus.
8)What is metamorphosis? Give examples.
ANSWER:-The transformation of the larva into adult through drastic changes
is called metamorphosis. Frogs and insects are examples of organisms
9)Differentiate between internal fertilization and external
fertilisation: Fusion of male
and female gametes inside female body.
Chances of the survival of the offspring are more. Therefore, a
small number of eggs are produced.
External fertilisation: Fusion of
male and female gametes outside female body.
Chances of survival of the offspring are less. Therefore, a
large number of eggs are produced