What could be the reasons for adopting contraceptive methods?
Frequent pregnancies have an adverse effect on the health of a woman. Frequent and unwanted pregnancies can be avoided by adopting contraceptive methods. Also, these methods check population growth by controlling child birth rate.
How are the modes for reproduction different in unicellular and multicellular organisms ?
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.
Differentiate between ‘self-pollination’ and ‘cross-pollination’. Describe double fertilisation in plants.
What is the effect of DNA copying which is not perfectly accurate on the reproduction process?
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.
Name one sexually transmitted disease each caused due to bacterial infection and viral infection. How can these be prevented?
Explain the following methods of contraception giving one example of each:
(i) Barrier method
(ii) Hormonal imbalance method
(iii) Surgical method.
What is reproduction? What are its two types? Which one of the two confers new characteristics on the offsprings and how?
“Variations that confer an advantage to an individual organism only will survive in a population.” Justify.
(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?
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.
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.
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?
What are sexually transmitted diseases?
Name four such diseases. Which one of them damages the immune system of human body?
Name the two types of germ-cells present in human beings. How do they structurally differ from each other? Give two differences.
If a woman is using a copper-T will it help in protecting her from sexually transmitted diseases?
(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.
(a) Explain the terms:
(i) Implantation (ii) Placenta
(b) What is the average duration of human pregnancy?
List any four reasons for vegetative propagation being practised in the growth of some type of plants.
(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.
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?
Explain vegetative propagation with the help of two examples. List two advantages of vegetative propagation.
Name an organism which reproduces by spore formation. List three conditions favourable for spores to germinate and grow.
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.
Name the information source of making proteins in the cell. State two basic events in reproduction.