Here in this post we provided NCERT Exemplar Problem Class 7 Science Reproduction in Plants Chapter 12 Full Explanation by group of Science Experts. We have provided here each questions answer with reason behind the answer.
Hope it help you!
Reproduction in Plants Class 7 Exemplar full Explanation:
3) Seeds of drumstick and maple are carried to long distance by wind because they possess
a) Winged seeds
b) Large and hairy seeds
c) Long and ridged fruits
d) Spiny seeds
Answer:- a) winged seeds
Winged seeds are specialized character for Transportation of seeds by the wind.
4) The ‘eye’ of the potato plant is what
a) The root is to any plant.
b) The bud is to a flower.
c) The bud is to Bryophyllum leaf .
d) The anther is to stamen.
Answer:- c) the bud is to Bryophyllum leaf.
The eye of the potato plant is Bryophyllum leaf.
5) The ovaries of different flowers may contain
a) Only one ovule
b) Many ovules
c) One to many ovules
d) Only two ovules.
Answer:- c) one to many ovules
The ovaries of different flowers may containone to many ovules.
6) Which of the following statements is /are true for sexual reproduction in plants?
i) Plants are obtained from seeds.
ii) two plants are always essential.
iii) fertilisation can occur only after pollination.
iv) only insects are agents of pollination.
Choose from the options given below:
a) I and III
b) I only
c) II and III
d) I and IV
Answer:- a) I and III
Plants are obtained from seeds and fertilisation can occur only after pollination are right among above. Two plants are not always essential for the reproduction there are several ways in which reproduction takes by single plant. And only insects are not agent of pollination. Wind, water, animals ,bats are also agents of pollination.
7) Pollination refers to the
a) Transfer of pollen from anther to ovary.
b) Transfer of male gametes from anther to stigma.
c) Transfer of pollen from anther to stigma.
d) Transfer of pollen from anther to ovule.
Answer:- c) Transfer of pollen from anther to stigma.
The term pollination means that the transfer of pollen grain from anther to stigma.
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Very Short Answer Questions
8) Fungus, moss, and fern reproduce by a common method of asexual reproduction. Name the method.
Answer:- Fungus, moss and fern reproduce by the Asexual reproduction. They carry out asexual reproduction by means of spore formation. Spores are small , light weighted, asexual reproductive bodies, which is covered by a protective coat. These helps to withstand in favourable conditions, like high temperature, low humidity etc. For their survival. Under the favourable conditions spore started germination and develop into new individuals. When spores are released they float over the air as they are light weight and thus transfer from one place to another.
9) Pick the odd one out from the following on the basis of mode of reproduction and give reason for it.
Sugarcane, potato, rice , rose
Answer:- from the given question, the odd word is Rice. Rice does not reproduce by vegetative propagation . It is only reproduce from the seeds only. But the other Sugarcane , potato and rose can reproduce by vegetative propagation. It can propagate from stem And Bryophyllum leaves in potato.
10) Boojho had the following Parts of a rose plant – a leaf, roots , a branch , a flower, a bud and pollen grains. Which of them can be used to grow a new rose plant ?
Answer:- Rose plant can be grown by the process of vegetative propagation. That means it does not grow from seeds, but from the part of plant body. A new rose plant can be grown from the branch (stem) of the plant.
11) Which type of pollination does the figure 12.1 indicate ?
Answer:- The given figure indicates the process of self pollination. Pollination is the transfer of pollen grains form anther to the stigma of plant. Types of Pollination are self pollination and cross pollination and further classified . Self pollination occurs when a pollen grain is landed on the same flower or another flower but of the same plant. Here the pollen grains are transferred from same plant same flower.
12) One morning as paheli strolled in her garden she noticed many small plants which were not there a week ago. She wondered where they had come from as nobody had planted them there. Explain the reason for the growth of these plants.
Answer:- It is a natural process, that new small plantlets are grown in garden . As these is because of, the seeds are fallen over there of the nearer plants , which germinated due to moisture in soil. Also seeds are transferred from one place to another place by the agents such as birds and animals which eats fruits and excrete waste along with the seeds . Which are the grown over there.
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Short Answers Questions
13) In the diagram given in figure 12.2 label the parts marked. (a), (b), and (c).
Answer:
14) When you keep food items like bread and fruits outside for a long time especially during the rainy season. You will observe a cottony growth on them.
a) What is this growth called ?
Answer:- when a bread mould or fruit is kept outside for a longer time in rainy season, there is growth of fungus over it. These reproduce and spread by the small spores.
b) How does the growth take place?
Answer:- The growth of the Fungi over the bread mould is takes place due to the asexual reproduction of the spores. spores reproduce asexually and grow in the favourable conditions. These spores are light weighted so spread over air and transfer.
15) Group the seeds given in figure 12.3 (i) to (iii) according to their means of dispersion.
a) Seed dispersed by wind.
b) Seed dispersed by water.
c) Seed dispersed by animals.
Answer:-
Seed a) is dispersed by wind.
Seed b) is dispersed by Animals.
Seed c) is dispersed by wind.
16) Coconut is a large and heavy fruit. How is it adapted for dispersal by water ?
Answer:- Coconut is a large and heavy fruit but the dispersal occurs by the water . Coconut has spongy fibres by which coconut can float over the water easily and transfer from place to another place. When they transfer from one place to another they grow in favourable conditions over there.
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Long Answer Questions
17) In the figure of a flower given in figure 12.4 label the parts whose functions are given below and give their names.
a) The part which contains pollen grains.
Answer:- Anther
b) The part where the female gamete is formed.
Answer:- ovary
c) The female reproductive part where pollen grains germinate.
Answer:- stigma
d) The colourful part of flower which attracts insects.
Answer:- petals
’18) Fill in the blanks with correct terms.
The male and female gametes fuse to form a _____(a)_____ during the process of _____(b)_____ . This grows into an ____(c)_____ which is enclosed within a seed. After fertilisation the ovules develop into ____(d)_____ and the ovary develops into a _____(e)______.
Answer:-
The male and female gametes fuse to form a zygote during the process of fertilization . This grows into an embryo which is enclosed within a seed. After fertilisation the ovules develop into seed and the ovary develops into a fruit.
19) In the diagram of a bisexual flower given as figure. 12.5 draw the missing part and label the parts marked (a), (b) and (c). Also label the missing part that you draw.
Answer:-
20) Write how the following seeds are dispersed.
a) Seeds with wings
Answer:- seeds with wings are specially formed for dispersed with the wind.
b) Small and light seeds.
Answer:- small and light weighted seeds are dispersed by the wind .
c) Seeds with spines / hooks.
Answer:- seeds having spines / hooks are dispersed by the animals. They attached on the body of animals and transfer from one place to another.