1. Asexual reproduction takes place through budding in
(a) amoeba
(b) yeast
(c) plasmodium
(d) leishmania
Answer:
(b) Yeast
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
Answer:
(c) Vas deferens
3. The anther contains
(a) sepals
(b) ovules
(c) carpel
(d) pollen grains
Answer:
(d) Pollen grains
4. What are the advantages of sexual reproduction over
asexual reproduction?
Answer:
Sexual reproduction can generate more variations and speed
up the making of new variants by combining DNA copies from two individuals. All
these variations are accumulated and inherited from generation to generation.
It produces individuals with different patterns of variations in a population.
Thus the organism can adapt quickly to changes in its surroundings.
5. What are the functions performed by the testis in human
beings?
Answer:
· Testes produce male gametes (sperms).
· Testes produce a hormone called testosterone. It controls
the development of reproductive organs and secondary sexual characters.
6. Why does menstruation occur?
Answer:
If the ovum is not fertilised, the thick and soft inner
lining of uterus is no longer needed and hence breaks. So, the lining along with
the blood vessels and the dead ovum comes out of the vagina in the form of
blood. This is called menstruation.
7. Draw a labelled diagram of the longitudinal section of a
flower.
Answer:
8. What are the different methods of contraception?
Answer:
a) Barrier method: E.g.,
condom, diaphragm and cervical caps. These prevent the entry of sperms in the
female genital tract.
b) Chemical method: Use
of oral and vaginal pills. The oral pills suppress the release of ovum. The
vaginal pills/ creams are spermicidal.
c) Intrauterine contraceptive devices: E.g., Copper-T. It prevents the sperms to reach the
uterus.
d) Surgical method: It includes vasectomy in males and tubectomy in females. In
vasectomy, a small part of vas deferens is cut or tied. In tubectomy, fallopian
tube is cut or tied.
9. How are the modes for reproduction different in
unicellular and multicellular organisms?
Answer:
|
Reproduction
mode in unicellular organisms |
Reproduction
mode in multicellular organisms |
|
Asexual reproduction. |
Asexual or Sexual. |
|
Only one parent is needed. |
For sexual reproduction, two
parents are needed. |
|
No special cells. |
Special cells are present. |
|
No special organs are
present for reproduction. |
Special organs are present
for reproduction. |
10. How does reproduction help in providing stability to
populations of species?
Answer:
Reproduction helps to generate copies of individuals which
are suited to a particular environment.
The formation of variations during reproduction provides
stability to the populations to adapt various environmental conditions.
11. What could be the reasons for adopting contraceptive
methods?
Answer:
· To control the birth rate and population explosion.
· To reduce the adverse effects on mother’s body due to
frequent pregnancy.
· To prevent sexually transmitted diseases.