Explain vegetative propagation with the help of two examples. List two advantages of vegetative propagation.
In vegetative propagation, new plants are obtained from the parts of old plants like stems, roots and leaves, without the help of any reproductive organ.
There are two ways of vegetative propagation:
(a) Natural Vegetative Propagation, and
(b) Artificial Vegetative Propagation.
Natural vegetative propagation by leaves: The fleshy leaves of Bryophyllum bear adventitious buds in the notches along the leaf margin.
Grafting: In this method of reproduction, two plants of closely related varieties are joined together so that they live as one plant.
(i) Vegetative propagation is a cheaper, easier and more rapid method of propagation in plants than growing plants from their seeds.
(ii) Better quality of the plants can be maintained by this method.
What is the effect of DNA copying which is not perfectly accurate on the reproduction process?
Which of the following is not a pan Of the female reproductive system in human beings ?
(a) Ovary
(b) Uterus
(c) Vas deferens
(d) Fallopian tube
(a) Explain the role of placenta in the development of human embryo.
(b) Give example of two bacterial and two viral sexually transmitted diseases. Name the most effective contraceptive which prevents spread of such diseases.
State one genetically different feature between sperms and eggs of humans. What is its consequence?
Name one sexually transmitted disease each caused due to bacterial infection and viral infection. How can these be prevented?
Can you think of reasons why more complex organisms cannot give rise to new individuals through regeneration?
How are the modes for reproduction different in unicellular and multicellular organisms ?
List any four reasons for vegetative propagation being practised in the growth of some type of plants.
a) List any four reasons for adopting contraceptive methods.
(b) If a woman is using Copper-T, will it help in protecting her from sexually transmitted diseases? Why?
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.
“DNA copies generated during reproduction will be similar but may not be identical to the original.” Justify this statement.
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.
What is reproduction? What are its two types? Which one of the two confers new characteristics on the offsprings and how?
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?
What are sexually transmitted diseases?
Name four such diseases. Which one of them damages the immune system of human body?
(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) 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.
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.
(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?
What does HIV stand for? Is AIDS an infectious disease? List any four modes of spreading AIDS.
(a) Draw a diagram showing germination of pollen on stigma of a flower.
(b) Label pollen grain, male germ- cells, pollen tube and female germ-cell in the above diagram.
(c) How is zygote formed?
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?
Differentiate between ‘self-pollination’ and ‘cross-pollination’. Describe double fertilisation in plants.
(a) Explain the terms:
(i) Implantation (ii) Placenta
(b) What is the average duration of human pregnancy?