1) A sexual
reproduction takes place through budding in
reproduction takes place through budding in
(a)
amoeba.
amoeba.
(b)
yeast.
yeast.
(c)
plasmodium.
plasmodium.
(d)
leishmania.
leishmania.
ANSWER:-(b)
yeast
yeast
2) Which
of the following is not a part of the female reproductive system in human
beings?
of the following is not a part of the female reproductive system in human
beings?
(a)
Ovary
Ovary
(b)
Uterus
Uterus
(c) Vas
deferens
deferens
(d)
Fallopian tube
Fallopian tube
ANSWER: -(c)
Vas deferens
Vas deferens
3) The
anther contains
anther contains
(a)
sepals.
sepals.
(b)
ovules.
ovules.
(c)
carpel.
carpel.
(d)
pollen grains.
pollen grains.
ANSWER:-(d)
Pollen grains
Pollen grains
4) What
are the advantages of sexual reproduction over asexual reproduction?
are the advantages of sexual reproduction over asexual reproduction?
ANSWER:-Advantages:-
1. In sexual reproduction,
more variations are produced. Thus, it ensures survival of species in a
population.
more variations are produced. Thus, it ensures survival of species in a
population.
2. The new formed individual
has characteristics of both the parents.
has characteristics of both the parents.
3. Variations are more viable
in sexual mode than in asexual one. This is because in asexual reproduction,
DNA has to function inside the inherited cellular apparatus.
in sexual mode than in asexual one. This is because in asexual reproduction,
DNA has to function inside the inherited cellular apparatus.
5) What
are the functions performed by the testis in human beings?
are the functions performed by the testis in human beings?
ANSWER:-Functions of testes:
1 .Produce
sperms
sperms
2. Produce
a hormone called testosterone,which brings about secondary sexual characters in
boys.
a hormone called testosterone,which brings about secondary sexual characters in
boys.
6) Why
does menstruation occur?
does menstruation occur?
ANSWER:-This
process occurs every month because one egg is released from the ovary every
month and at the same time, the uterus (womb) prepares itself to receive the fertilized egg. Thus,
the inner lining of the uterus gets thickened and is supplied with blood to
nourish the embryo. If the egg does not get fertilised, then the lining of the uterus breaks down slowly and
gets released in the form of blood and mucous from the vagina.
process occurs every month because one egg is released from the ovary every
month and at the same time, the uterus (womb) prepares itself to receive the fertilized egg. Thus,
the inner lining of the uterus gets thickened and is supplied with blood to
nourish the embryo. If the egg does not get fertilised, then the lining of the uterus breaks down slowly and
gets released in the form of blood and mucous from the vagina.
7) Draw
a labelled diagram of the longitudinal section of a flower.
a labelled diagram of the longitudinal section of a flower.
ANSWER:-
8) What
are the different methods of contraception?
are the different methods of contraception?
ANSWER:-a)
Natural method→ It involves avoiding the chances of meeting of sperms and ovum.
In this method, the sexual act
is avoided from day 10th to 17th of the menstrual cycle because during this
period, ovulation is expected
and therefore, the chances of fertilization are very high.
Natural method→ It involves avoiding the chances of meeting of sperms and ovum.
In this method, the sexual act
is avoided from day 10th to 17th of the menstrual cycle because during this
period, ovulation is expected
and therefore, the chances of fertilization are very high.
b) Oral contraceptives →In this
method, tablets or drugs are taken orally. These contain small doses of hormones
that prevent the release of eggs and thus fertilization cannot occur.
method, tablets or drugs are taken orally. These contain small doses of hormones
that prevent the release of eggs and thus fertilization cannot occur.
c) Barrier
method → In this method, the fertilization of ovum and sperm is prevented
with the help of barriers.
Barriers are available for both males and females.
method → In this method, the fertilization of ovum and sperm is prevented
with the help of barriers.
Barriers are available for both males and females.
d) Implants
and surgical methods
and surgical methods
→Contraceptive devices such as the loop or Copper-T are placed in
uterus to prevent pregnancy. Some surgical methods can also be used to block
the gamete transfer.
uterus to prevent pregnancy. Some surgical methods can also be used to block
the gamete transfer.
9) How
are the modes for reproduction different in unicellular and multicellular
are the modes for reproduction different in unicellular and multicellular
Organisms?
ANSWER:-In
unicellular organisms, reproduction occurs by the division of the entire cell.
The modes of reproduction in unicellular organisms can be fission, budding, etc.
whereas in multicellular organisms, specialised reproductive organs are
present. Therefore, they can reproduce by complex reproductive methods such as
vegetative propagation,
spore formation, etc. In more complex multicellular organisms such as human beings and plants,
the mode of reproduction is sexual reproduction.
unicellular organisms, reproduction occurs by the division of the entire cell.
The modes of reproduction in unicellular organisms can be fission, budding, etc.
whereas in multicellular organisms, specialised reproductive organs are
present. Therefore, they can reproduce by complex reproductive methods such as
vegetative propagation,
spore formation, etc. In more complex multicellular organisms such as human beings and plants,
the mode of reproduction is sexual reproduction.
10) How
does reproduction help in providing stability to populations of species?
does reproduction help in providing stability to populations of species?
ANSWER: –
It helps in providing stability
to the population of species by producing a new individual that resembles the
parents.
It helps in providing stability
to the population of species by producing a new individual that resembles the
parents.
11) What
could be the reasons for adopting contraceptive methods?
could be the reasons for adopting contraceptive methods?
ANSWER:-Contraceptive
methods are mainly adopted because of the following reasons:
methods are mainly adopted because of the following reasons:
(i) To
prevent unwanted pregnancies.
prevent unwanted pregnancies.
(ii) To
control population rise or birth rate.
control population rise or birth rate.
(iii) To prevent
the transfer of sexually transmitted diseases.
the transfer of sexually transmitted diseases.