How Do Organism Reproduce : NCERT Exercise Questions


Q.1     Asexual reproduction takes place through budding in :
                  (a) Amoeba     (b) Yeast     (c) Plasmodium     (d) Leishmania
Sol.       (b) Yeast

Q.2      Which of the following is not a part of the female reproductive system in human beings?
                    (a) Ovary        (b) Uterus   (c) Vas deferens    (d) Fallopian tube
Sol.         (c) Vas deferens.

Q.3       The anther contains :
                     (a) Sepals       (b) Ovules   (c) Carpel            (d) Pollen grains
 Sol.         (d) Pollen grains

Q.4       What are the advantages of sexual reproduction over asexual reproduction ?

Advantages of Sexual Reproduction over asexual reproduction are :-
It promotes diversity.
It results genetic variations.
It contributes to evolution of species.
It results in origin of new species.

Q.5        What are the functions performed by testes in human beings?

Functions of Testes in human beings are :
Formation of male gametes called sperms.
Formation of male sex hormone (testosterone).

Q.6        Why does menstruation occur ?
Sol.           In human female, one mature egg forms each month from the onset of puberty.
                  When this egg is not fertilized then menstruation occur.

Q.7        Draw a labeled diagram of the longitudinal section of a flower.
Sol. Untitled-2Untitled-2Untitled-2Untitled-22.jpg2.jpg2.jpg

Q.8       What are the different methods of contraception?

Methods of contraception :-
(i) Use Barriers - It prevents the sperm to reach the egg. For eg. Condoms, Diaphragm.

(ii) Chemicals - There are various chemicals or medicines which act by changing the hormonal balance of the body, So that fertilization cannot occur.

(iii) Surgical - If vas deferens in male or fallopian tube in female is blocked , transfer of sperm or transfer of egg will be prevented respectively.

Q.9       How are the modes of reproduction different in unicellular and multicellular organisms?

Unicellular organisms reproduce by asexual methods like fission, budding while multicellular organisms reproduce by sexual method & asexual method both. For ex. Guava is a multicellular plant that reproduce by vegetative propagation and sexual reproduction.

Q.10     How does reproduction help in providing stability to populations of species ?

Reproduction is the process of producing new individuals of the same species by existing organisms of a species, so, it helps in providing stability to population of species by giving birth to new individuals as the rate of birth must be at par with the rate of death to provide stability to population of a species.

Q.11     What could be the reasons for adopting contraceptive methods?

Reasons for adopting contraceptive methods :-
Helps in family planning (Birth control)
To avoid unwanted pregnancy.
It provides protection from sexually transmitted diseases like HIV.


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