Lesson: How do Organisms Reproduce
Asexual
reproduction takes place through budding in _____________.
(a)
Amoeba.
(b) Yeast.
(c) Plasmodium.
(d)
Leishmania.
(b)
Which
of the following is not part of the female reproductive system in human beings?
(a)
Ovary
(b)
Uterus
(c)
Vas deferens
(d)
Fallopian tube
(c)
The
anther contains:
(a)
Sepals.
(b)
Ovules.
(c)
Carpel.
(d)
Pollen grains.
(d)
What
are the advantages of sexual reproduction over asexual reproduction?
Sexual reproduction produces more variations. The
newly formed individual has characteristics of both parents. Thus, evolution of
new and complex species is possible because of sexual reproduction.
What are the functions performed
by the testis in human beings?
Functions of
testis:
·
Produce
sperms
·
Produce
a hormone called testosterone, which brings secondary sexual characters in
boys.
Why does menstruation occur?
In each
ovulation cycle, an egg is released from an ovary and transferred to the
fallopian tube. At the same time, the uterus prepares itself to receive a fertilized
egg. Thus, the inner lining of the uterus thickens and is supplied with blood
to nourish the embryo. If the egg does not fertilize, the lining of the uterus
breaks down slowly, and gets released out through the vagina in the form of
bleeding with blood, mucus and the discarded egg. This release unwanted
particles through the vagina is called menstruation.
Draw
a labelled diagram of the longitudinal section of a flower.
What
are the different methods of contraception?
·
Natural
method
·
Barrier
method
·
Chemical
method
·
Implants
and surgical method
How
are the modes for reproduction different in unicellular and multicellular
organisms?
Unicellular
organisms always reproduce by asexual methods, such as binary fission, budding,
etc. Multicellular organisms use both asexual and sexual methods. Simple
organisms follow asexual methods of reproduction and other multicellular
organisms follow sexual methods of reproduction.
How does reproduction help in providing stability
to the population of a species?
Reproduction
helps in providing stability to the population of a species by producing a new
individual that resembles their parents.
Every species
on Earth has to constantly adopt in order to survive. The natural cycle of
birth and death, natural predators and vagaries of nature continue to remove a
large section of the population of a particular species. So, living organisms
reproduce to replenish the lost section of their population.
What
could be the reasons for adopting contraceptive methods?
Contraceptive methods are mainly adapted to:
(i) Prevent unwanted pregnancies
(ii) Control population rise or birth rate
(iii) Prevent the transfer of sexually transmitted
diseases