Selina ICSE Class 9 Biology Solutions Chapter 6 Seeds Structure And Germination

Q1. Multiple choice type

Question 1. Which one of the following plants parts is correctly matched with one of its stated characteristic?
a) Mango seed ___________ aleurone layer
b) Bean seed __________ endosperm
c) Maize grain __________ coleoptile
d) Wheat grain ___________ exalbuminous

2) Seeds sown very deep in the soil fail to germinate because they
a) cannot exert enough force to push the soil upward.
b) do not get enough sunlight.
c) get too much water.
d) do not get enough oxygen.

Question 2. Is the following statement true (T) or false (F)?

1) Maize grain is fruit and not a seed.

2) Seeds fell in a flower-bed from the previous crop usually do not germinate until the next sowing season.

3) Oxygen is necessary for the germination of seeds.

4) Some seeds have no cotyledons at all.

Q3) Name the following:

1) A monocotyledonous endospermic seed.

2) A chemical used in experiments which absorbs oxygen.

3) Part of the plumule above the embryonic axis of the seed.

4) A plant that shows viviparous germination.

5) The layer of the endosperm of maize rich in protein.

6) A seed with folded plumule leaves.

Q4) Fill in the blanks: 

1) In bean seeds, ________ grows faster and the seeds are brought _________ ground.

2) _______ is a protective layer of radicle and ________ protects the rolled plumule.

3) A seed is protected by ________ and __________ .

4) Seeds absorb water through __________ which also helps in the diffusion of respiratory gases.

5) Rich, wheat and maize are rich in _________ food

Q5) Arrange the following set of a term in order, so as to be in a logical sequence. Rewrite the correct order.

1) Embryo, 1^st male gamete, zygote, egg cell, micropyle.

2) Zygote, embryo, seed, allogamy, fusion of gametes.

3) Seed coat bursts, hypocotyls elongates, radicle grows downward, hypocotyls forms loop above the soil, epicotyls elongates.

Short Answer Type:-

Question 1. What is the difference between an embryo and a seed? 
Solution.
A seed is a mature ovule after fertilization. It contains a tiny living-plant called the embryo. The embryo within the seed remains in an inactive or dormant state, until it is exposed to favorable conditions, when it germinates.

Question 2. Give any two examples each of endospermic (albuminous) seeds, and non-endospermic (exalbuminous) seeds.
Solution.
Endospermic (albuminous) seeds: E.g. Castor, Maize, Poppy Non-endospermic (exalbuminous) seeds: E.g. Bean, Gram, Pea

Question 3. Germinated grams are considered highly nutritive. What is the reason for this belief?
Solution.
Germinated grams are considered highly nutritive because the cotyledon of the seed absorbs food from the endosperm, making it nutritive. It is rich in starch and its outermost layer is rich in protein.

Question 4. Why do we not use the terms maize fruit and maize seed? What do we say instead?
Solution.
Maize grain is actually a fruit in which the fruit wall and the seed coat are fused together to form a protective layer. Therefore, we do not use the terms maize fruit and maize seed. Instead, we call such fruits as grains.

Long answer type:-

Question 1. What is the function of the following in a seed?
a) Seed coat
b) Micropyle
c) Cotyledons
d) Radicle
e) Plumule
Solution.
(a) Seed coat: It protects the seed’s fragile interior sections from damage as well as germs, fungus, and insects.
(b) Micropyle: Micropyle permits water to enter the seed through its pore during germination.
(c) Cotyledons: They have nourishment for the embryo in them.
(d) Radicle: It will become the future root.
(e) Plumule: It helps to shape the upcoming shot.

Question 2. Suggest an experiment to prove that a suitable temperature is necessary for germination.
Solution.
The goal is to show that germination requires a specific temperature.
Apparatus: Refrigerator, two beakers, damp cotton wool
Label two beakers with the letters A and B.
In each beaker, place few gram seeds on wet cotton wool.
Refrigerate beaker B and keep beaker A at room temperature.
The seeds in beaker A germinate in 1-2 days, demonstrating the need of a sufficient temperature for germination. Beaker B seeds may not exhibit symptoms of germination or may germinate after many days, although not to the same extent as beaker A seeds.
Inference: Seeds must germinate at a specific temperature.

Question 3. Sometimes the potatoes kept in a basket during the late rainy season start giving out small shoots. Would you call it germination? Give reasons in support of your answer.
Solution.
Yes, we call it germination because it encompasses all of the events that contribute to the creation of a seedling. Either the epicotyl or the hypocotyl lengthens during germination.

Question 4. Give two differences in the following pairs:
(a) Epigeal germination and hypogeal germination
(b) Coleorhiza and coleoptile
(c) Bean seed and Maize grain
(d) Germination and vivipary
Solution.
(a) Epigeal germination and Hypogeal germination:-

Question 5. Justify the statement that the maize grain is a ‘one-seeded fruit’.
Solution.
The ovarian wall creates the fruit wall and encloses the seed in a fruit, which is an expanded ripening ovary. The seed is protected by the fruit, which also aids in seed dissemination.
Because the fruit wall and seed coat are united to create a protective shell, the maize grain is known as a “one-seeded fruit.” Grain is the name for such a fruit.

Question 6. What is the role played by the hypocotyl in epigeal germination?
Solution.
Epigeal germination refers to seed germination that takes place above earth. The hypocotyl forms a loop above the earth during epigeal germination. The cotyledons are then pushed above the earth when the stem straightens.

Question 8. Long answer type:-
1) With regard to germination in bean seed, answer the following question:
a) State the function of the ‘micropyle’.
b) Name the part of the seed that grows into the seedling.
c) Draw a neat labelled diagram of the structure named above.
d) Name the part of the seed that provides nutrition for the growing seedling.
Solution.

(a) The ‘micropyle’ has two vital functions:
• It allows the embryo to absorb water and make it ready for germination.
• Allows for the absorption of breathing gases into the developing embryo
(b) The seedling develops from the embryo of the seed.
(c) The seed’s cotyledons offer sustenance to the developing seedling or embryo.
(d) Embryonic structure