Students can Download Science Chapter 20 Reproduction in Higher Plants Questions and Answers, Notes Pdf, KSEEB Solutions for Class 8 Science helps you to revise the complete Karnataka State Board Syllabus and to clear all their doubts, score well in final exams.
Karnataka State Syllabus Class 8 Science Chapter 20 Reproduction in Higher Plants
KSEEB Class 8 Science Reproduction in Higher Plants Textbook Exercise Questions and Answers
I. Four alternatives are given to each of the following incomplete statements/ questions. Choose the right answer.
Question 1.
The seed develops from :
(a) ovary
(b) ovule
(c) embryo
(d) embryo sac
Answer:
(b) ovule
Question 2.
Colour of night-blooming flowers is usually
(a) violet
(b) red
(c) yellow
(d) whitish
Answer:
(d) whitish
Question 3.
The correct sequence of reproductive stages seen in flowering plants, is
(a) gametes, zygote, embryo, seedling
(b) zygote, gametes, embryo, seedling
(c) seedling, embryo, zygote, gametes
(d) gametes, embryo, zygote, seedling
Answer:
(a) gametes, zygote, embryo, seedling
Question 4.
The anther contains
(a) ovules
(b) female gametes
(c) overy
(d) pollen grains
Answer:
(d) pollen grains
II. Fill in the blanks with suitable words:
1) Flowers with blue petals, nectar and strong scent are most likely pollinated by _______.
2) Variations in the offspring is the characteristic of _______ reproduction.
3) There is much wastage of pollen grains in _______ pollination.
4) Fertilization leads to the formation of _______.
Answer:
1. insects,
2. sexual,
3. (wind) cross,
4- zygote
III. Answer the following:
Question 1.
What is reproduction?
Answer:
Reproduction is one of the characteristics of a living being, by which they continue their progeny.
Question 2.
What is sexual reproduction?
Answer:
The reproduction which involves the formation and fusion of male and female gametes is called sexual reproduction.
Question 3.
What is pollination?
Answer:
The process of transfer of pollen grains from the anther to the stigma is called pollination.
Question 4.
Are insects friends of farmers? Explain.
Answer:
In most plants cross-pollination is brought about with the help of insects like butterflies, moths and bees. Cross-pollination has many advantages to plants also. Therefore it is considered that insects are friends of farmers.
Question 5.
Draw the diagram of a typical flower and label the parts petal
Answer:
KSEEB Class 8 Science Reproduction in Higher Plants Additional Questions and Answers
I. Answer the following:
Question 1.
Mention the two basic types of reproduction.
Answer:
The two basic types of reproduction are asexual and sexual.
Question 2.
What is Calyx?
Answer:
The calyx is the outermost whorl of a flower, composed of green coioured units called sepal.
Question 3.
What do you mean by self pollination?
Answer:
If the pollen grains get transferred to the stigma of the same flower it is called self pollination.
Question 4.
What is meant by cross pollination?
Answer:
If the pollen grains get transferred to the stigma of another flower in another plant of the same species it is called cross-pollination.
Question 5.
Mention the agents of cross-pollination.
Answer:
Wind, water and animals are the agents of cross pollination.
Question 6.
Write the examples for wind pollinated plants.
Answer:
Sugarcane, maize and grass are common examples for wind pollinated plants.
Question 7.
Mention special features of wind pollinated flowers.
Answer:
The special features of wind pollinated flowers are
- flowers are generally small and dull coloured.
- they produce a large number of dry and light pollen grains.
Question 8.
How does cross pollination occur in aquatic plants?
Answer:
In aquatic plants generally male and female flowers are formed separately. The male flowers detach from the plant and float on the surface. The female flowers remain attached to the plant. Male flowers are carried towards the female flowers by water current; where they release pollen grains. Valisneria, Hydrilla and Elodea are the common examples.
Question 9.
Mention the modifications of the insect pollinated flowers.
Answer:
Insect pollinated flowers show certain modifications to attract insects. These modifications are mainly concerned with the colour of the petals. Some flowers contain glands called nectarus which produce the nectar to attract the insects that bring about cross pollination. Flowers which open during night, usually have a dull colouration but have an aromatic smell that attracts insects.
Question 10.
What is fertilization?
Answer:
Fertilization is the fusion of haploid male gamete in the pollen grain with the haploid female gamete in the ovule.
Question 11.
How does fertilization take place?
Answer:
To bring about fertilization, the pollen grains which get deposited on the stigma of the carpel must penetrate the style and reach the ovule. The pollen tube grows through the length of the style and ovule and finally reaches the embryo sac which encloses the female gamete. Male and female gamete unite together. Thus fertilization takes place resulting in the formation of a diploid cell called zygote.
Question 12.
Write the changes that take place in the flower after pollination and fertilization.
Answer:
The changes that takes place in the flower after pollination and fertilizers are the following
- The diploid zygote develops into an embryo which later differentiates into a seed, which later grows into a new plant.
- Surrounding the embryo, a nutritive tissue called endosperm is formed.
- The entire ovule becomes the seed
- The covering of ovule transforms into seed coat.
- Ovary portion of carpel gets transformed into the fruit enclosing the seed.
- Petals, sepals and other parts of the flower fall off.