Lesson: How do Organisms Reproduce
Asexual reproduction takes place through budding in _____________.
Which of the following is not part of the female reproductive system in human beings?
(c) Vas deferens
(d) Fallopian tube
The anther contains:
(d) Pollen grains.
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