How Do Organisms Reproduce?


Mention the mode of reproduction used by
(a) Amoeba (b) Planaria.


Mode of reproduction used by
(a) Amoeba is Binary fission.
(b) Planaria is Regeneration.


How Do Organisms Reproduce?

Q 1.

How are the modes for reproduction different in unicellular and multicellular organisms ?

Q 2.

Name the largest cell present in the human body.

Q 3.

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

Q 4.

List two advantages of practising vegetative propagation in plants. Select two plants raised by this method from the list given below:
Banana, Gram, Pea, Rose, Tomato, Wheat.

Q 5.

How does binary fission differ from multiple fission ?

Q 6.

Differentiate between ‘self-pollination’ and ‘cross-pollination’. Describe double fertilisation in plants.

Q 7.

What is ‘reproduction’? Mention the importance of DNA copying inreproduction.

Q 8.

What are the advantages of sexual reproduction over asexual reproduction?

Q 9.

What is the importance of DNA copying in reproduction?

Q 10.

What is the effect of DNA copying which is not perfectly accurate on the reproduction process?

Q 11.

List any four modes of asexual reproduction.

Q 12.

List and explain in brief three methods  of contraception.

Q 13.

Define the terms unisexual and bisexual giving one example of each.

Q 14.

Mention the mode of reproduction used by
(a) Amoeba (b) Planaria.

Q 15.

How does the embryo get nourishment inside the Mother’s body?

Q 16.

What is AIDS? Which microbe is responsible for AIDS infection? State one mode of transmission of this disease. Explain in brief one measure for the prevention of AIDS.

Q 17.

Define the term puberty. List two  changes observed in girls at the time of puberty.

Q 18.

Name one sexually transmitted disease each caused due to bacterial infection and viral infection. How can these be prevented?

Q 19.

Why is vegetative propagation practised for growing some type of plants?

Q 20.

What are the changes seen in girls at the time Of puberty ?

Q 21.

Explain the following methods of contraception giving one example of each:
(i) Barrier method
(ii) Hormonal imbalance method
(iii) Surgical method.

Q 22.

“Variations that confer an advantage to an individual organism only will survive in a population.” Justify.

Q 23.

What is reproduction? What are its two types? Which one of the two confers new characteristics on the offsprings and how?

Q 24.

Write the full form of DNA. Name the part of the cell where it is located. Explain its role in the process of reproduction of the cell.

Q 25.

Draw a longitudinal section of a flower and label the following parts:
(i) Part that produces pollen grain.
(ii)Part that transfers male gametes to the female gametes.
(iii) Part that is sticky to trap the pollen grain.
(iv) Part that develops into a fruit.

Q 26.

What is meant by asexual reproduction? List its any two different forms.

Q 27.

State in brief the changes that take place in a fertilised egg (zygote) till birth of the child in the human female reproductive system. What happens to the egg when it is not fertilised?

Q 28.

(a) In the human body what is the role of
(i) seminal vesicles, and (ii) prostate gland?
(b) List two functions performed by testis in human beings.

Q 29.

What are sexually transmitted diseases?
Name four such diseases. Which one of them damages the immune system of human body?

Q 30.

Name the two types of germ-cells present in human beings. How do they structurally differ from each other? Give two differences.

Q 31.

Why is variation beneficial to the species but not necessarily for the individual?

Q 32.

What are the functions performed by the testes in human beings?

Q 33.

(a) Name the parts labelled A, B, C, D and E.
(b) Where do the following functions occur?
(i) Production of an egg
(ii) Fertilisation
(iii) Implantation of zygote.
(c) What happens to the lining of uterus:
(i) before release of a fertilised egg?
(ii) if no fertilisation occurs?

Q 34.

Draw a diagram of a human female reproductive system and label the part
(i) that produces egg
(ii) where fusion of egg and sperm take place
(iii) where zygote is implanted
What happens to human egg when it is not fertilised?

Q 35.

What is the role of the seminal vesicles and the prostate gland ?

Q 36.

If a woman is using a copper-T will it help in protecting her from sexually transmitted diseases?

Q 37.

Why does menstruation occur?

Q 38.

How does reproduction help in providing stability to populations Of species?

Q 39.

What could be the reasons for adopting contraceptive methods?

Q 40.

(a) Explain the terms:
(i) Implantation (ii) Placenta
(b) What is the average duration of human pregnancy?

Q 41.

Explain vegetative propagation with the help of two examples. List two advantages of vegetative propagation.

Q 42.

Expand AIDS. List any four methods of prevention (control) of AIDS.

Q 43.

(a) What is fragmentation in organism?
Name a multicell-ular organism which reproduces by this method.
(b) What is regeneration in organism? Describe regeneration in Planaria with the help of a suitable diagram.

Q 44.

Describe in brief the role of (i) testis (ii) seminal vesicle, (iii) vas deferens, (iv) ureter and (v) prostate gland in human male reproductive system.

Q 45.

State the method used for growing rose plants.

Q 46.

List any four reasons for vegetative propagation being practised in the growth of some type of plants.

Q 47.

Why is DNA copying an essential part of the process of reproduction?

Q 48.

What does HIV stand for? Is AIDS an infectious disease? List any four modes of spreading AIDS.

Q 49.

Name an organism which reproduces by spore formation. List three conditions favourable for spores to germinate and grow.

Q 50.

“DNA copies generated during  reproduction will be similar but may not be identical to the original.” Justify this statement.