Class 6 - Biology - The Flower - Exercise And Solutions

EXERCISE

Multiple Choice questions:

1. Tick (√) the appropriate answer.

(i) In a germinating seed the roots develop from.

(a) Radicle (b) Plumule

(ii) In a germinating seed the shoot develops from

(a) Radicle (b) Plumule

(iii) Which one of the following is a monocotyledonous seed?

(a) Bean (b) Pea

(c) Maize (d) Gram

(iv) If the cotyledons are pushed above the soil, then such type of

germination is called

(a) Epigeal (b) Hypogeal

(v) If the cotyledons remain under the soil, then such type of

germination is called

(a) Epigeal (b) Hypogeal

(vi) Pollen is produced in the

(a) Filament (b) Style

(vii) Reproductive whorl of a flower are

(a) Stamen and carpels (b) Sepals and petals

(viii) Which one of the following is a false fruit?

(a) Tomato (b) Apple

(ix) In a seed food is generally stored in

(a) Radicle (b) Plumule

Short Answer questions

1. Giving below is a longitudinal section of a bean seed. Level the parts

Marked 1 to 5 and right their functions.

1. Testa: It is the outer exposed

part of of the seed.

2. Plumule: It is located between

The two cotyledons and

develops in to a shoot.

3. Radicle: It is located between

The two cotyledons and

develops in to a root.

4. Micropyle: It absorbs and allows the entry of as much as water as is

required for germination.

2. Name the following:

a) A seed which shows hypogeal germination. ------Pea

b) A monocot seed. --------Maize grain

c) A dicot seed. ----------Bean seed

d) A seed which shows epigeal germination -------Bean seed

3. Differentiate between the following pairs of terms:

a) Radicle and plumule

The radicle develops in to a root, while the plumule develops in to a

shoot.

b) Hilum and micropyle.

Hilum is the inner concave side of the seed, where the seed was

attached to the fruit wall. Micropyle is a small pore which absorbs

and allows water required for germination.

c) Testa and tegmen.

Testa is the outer exposed part of the seed coat, whereas tegmen

is a thin membrane and lies under the testa. It is the inner part of

the seed coat

4. Give two functions of fruit.

The two functions of fruit are

i) It protects the seed from the unfavorable environmental

conditions.

ii) Fruits store food inside them.

5. Match the columns:

Column A Column B

a) Radicle i) Shoot

b) Plumule ii) Store food material

c) Cotyledon iii) Root

d) Testa iv) Absorb water needed for germination

e) Micropyle v) Protection of seed

Ans. a- iii, b- i, c- ii, d- v, e- iv

6. Radicle emerges out of the seed earlier than plumule. State one

advantage served by this.

As the radicle emerges out of the seed earlier and develop in to a

root it helps in providing water and mineral for further growth of the

plumule.

7. State whether the following statements are TRUE or FALSE

a) Some seeds have no cotyledons. FALSE

b) Warmth is necessary for germination of seeds. TRUE

c) All seeds have two cotyledons. FALSE

d) Oxygen is necessary for germination of seeds. TRUE

8. State one function of the following:

a) Radicle: It develops in to a root.

b) Cotyledons: It stores the food material which is used by the seedling

for growth.

c) Endosperm: It stores food in the form of starch.

d) Micropyle: It absorbs and allows the entry of as much as water as is

required for germination.

9. The three conditions necessary for germination of seeds are ( Tick the

correct answer):

a) Oxygen, suitable temperature and water. √

b) Good soil, water and air.

c) Good soil, suitable temperature and light.

d) Light, oxygen and temperature.

e) Oxygen, carbon dioxide and light

10. Name the part of the seed from which the following are given out:

(a) Roots: Radicles

(b) Leaves: Plumule

11. In the spaces provided below, draw labelled diagram to show the

three stages in the germination of any seed you have observed.

Long answer questions:

1. What is meant by pollination? Name two types of pollination.

Pollination is the transfer of pollen grains from the anthers to the stigma

of a flower.

The two types of pollination are

a) Self pollination: It occurs within a single flower or between the flowers

of same plant.

b) Cross Pollination: It occurs in flowers of different plants of same kind.

2. Imagine all the seeds produced by a plant happen to fall under the

same plant and sprout in to new plants. Mention any two problems

that will be faced by the new plants.

If all the seeds produced by a plant happen to fall under the same

plant and sprout in to new plants, then the following problem will

happen.

a) As a large number of plants will grow in a very small area, the water

and minerals available for the plants will be very limited.

b) The air and sunshine for them will be not enough. As a result most of

the sprouts will die.

3. What is a flower? Draw a typical flower and level its different parts.

A flower is the most beautiful and colourful part of a plant which serves as a reproductive organ.

4. With the help of a suitable diagram, describe the structure of a dicot

seed.

The bean seed is an example of a dicot seed, whose diagram is shown

below.

The green outermost

covering of the seed is

called the seed coat. It

protects the seed from

insects and bacteria as

well as from mechanical

injury.

The seed coat is again

Made up of two parts. The

outer exposed part is

called the testa and the

inner part is called tegmen.

A scar called hilum is present in the inner concave side of the seed.

This is the place where the seed is attached to the fruit wall.

Above the hilum there is a small pore called micropyle. It absorbs and

allows the entry of water required for germination.

The seed is made up of two fleshy seed leaves called the cotyledons.

They contain stored food material which is used by the seedling for

growth.

In between the two cotyledons a delicate embryo is located, which is

consist of radicle and plumule. The radicle develops in to a root and

the plumule develops in to a shoot.

5. Define germination. Name two types of germination. Explain with

example.

The process by which the embryo in the seed becomes active in the

presence of water, air and suitable temperature and grows in to a

young plant is called germination.The two types of germination are

epigeal germination and hypogeal germination.

Epigeal germination: The type of germination in which, the cotyledons

are pushed above the soil is called epigeal germination. The leaves

unfold and start preparing food for the growing plant.

Germination of a bean seed is an example of epigeal germination.

Hypogeal germination: The type of germination in which the cotyledons

remain below the ground is called hypogeal germination. The plumule

only comes out of the soil to form leaves.

Germination of pea seed and maize grain are examples of hypogeal

germination

6. What are the three conditions necessary for the germination of seeds?

Water, air and favorable temperature are the three conditions required

or the germination of seeds.

7. Give the main differences between hypogeal and epigeal germination.

Hypogeal germination	Epigeal germination
Cotyledons remain below the ground.	Cotyledons are pushed above the ground.
Epicotyl elongates faster than hypocotyl, hence cotyledons remain below.	Hypocotyl elongates faster than epicotyl. Hence cotyledons get pulled above.
Examples: maize, rice, ground nut	Examples: bean, tamarind, papaya, cucumber

8. State the location of the following in a flower.

(a) Sepals: Sepals are the green outermost part of a flower.

(b) Petals: This forms the second inner whorl. Petals are the large,

fragrant and brightly coloured parts of the flower.

of the stamen bears the anther at its tip.

(d) Stigma: It is located in the fourth and the innermost whorl of the

flower. The style bears the stigma at its tip.

9. Given below the diagram of a typical flower. Label the parts marked by

Guidelines.

10. Give the difference in the function between the following parts.

(a) Ovary and ovule (b) Petal and sepal

(a) Ovary and ovule

Ovary	Ovule
It is the female reproductive part of a flower.	Ovule is located inside the ovary.
After fertilization the ovary turns in to a fruit.	Ovule turn in to seed after fertilization.

(b) Petal and sepal

Petal	Sepal
Petal is present in the second inner whorl of the flower.	It is the outermost whorl of a flower.
Petals are usually coloured or white but never green. It makes the flower attractive and attracts the insects for pollination.	Sepals are green leaf like structures. They enclose the inner part of the flower to provide necessary protection to growing bud.

Filament	Style
Filament is a thin thread like structure which bears the anther on its tip.	Style bears an expanded stigma at its tip and transfers the male gametes of the pollen grain in to the ovary.

(d) Pollen grains and ovule

Pollen grains	Ovule
Pollen grains contain the male gametes.	Ovule contains the female gametes.
Pollen grains germinate to produce pollen tubes, which carry the male gametes to the ovary.	After fertilization the ovule develops in to a seed.

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Extra Questions and Answers

A. Objective Questions

1. Fill in the blanks:

a) The flower is attached to the shoot by means of stalk or pedicel.

b) The androecium is called the male reproductive part of the flower.

c) The gynoecium is called the female reproductive part of the flower.

d) The gynoecium is made up of the carpel or the pistil.

e) The three parts of pistil are ovary, style and stigma.

f) The ovary contains small rounded bodies called ovules.

g) The fusion of male and female gametes is called fertilization.

h) A fruit is the ripened ovary.

i) Hilum is the place where the seed is attached to the fruit wall.

J) The upper large part of the maize grain is called the endosperm.

k) After the pollen grain reaches the stigma of the flower, it produces

pollen tubes.

2. Give one word for the following.

a) The outermost whorl of flower – Sepals.

b) The second whorl of sepals in china rose – Petals.

c) A flower pollinated by bats – Guava.

d) The dry outer skin of fruit – Epicarp.

e) The thick tough outer seed coat – Testa.

f) Covering of plumule in monocotyledon – Coleoptile.

g) In monocot seeds, radicle is covered by a protective covering

called – Coleorhiza

h) The protein rich layer surrounding the endosperm is called – Aleurone

layer.

B. Short Questions And Answers.

1. Name the four whorls of a flower.

The four whorls of a flower are calyx, corolla, androecium and

gynoecium.

2. What do you mean by a complete and incomplete flower?

When all the four whorls, calyx, corolla, androecium and gynoecium

Are present in a flower, it is said as a complete or bisexual flower and

If anyone whorl is missing in a flower it is said to be an incomplete flower.

3. What is the function of a flower?

The main function of flower is to produce seeds and fruits.

4. What are the agents of pollination?

Some agents of pollination are insects, wind, water and animals.

5. What happens to each part of the flower after fertilization?

After fertilization the ovary grows in to a fruit. The ovules inside the ovary

develops in to seed. The sepals and petals fall off.

6. What is a false fruit? Define with example.

In some cases the thalamus of the flower develops in to a fruit and not

the ovary. The ovary remains as a small central part containing the

seeds. These types of fruits are called false fruits. Apple and pear are

some example of false fruit.

7. What are the functions of a fruit?

i) It protects seeds from the unfavorable environmental condition.

ii) Fruits store food inside them.

iii) It helps in dispersing the seeds and facilitate their germination.

C. Long Questions And Answers.

Answer the following:

1. What are the different types of flowers?

Flowers can be divided in to two types. Bisexual flower and Unisexual

flower.

Bisexual flower: The flower having both male and female reproductive

parts(androecium and gynoecium) are called bisexual flowers.

Unisexual flower: The flowers having either the male reproductive part

(Androecium) or female reproductive part (gynoecium) are called

unisexual flowers.

2. Define fertilization. Describe the process of fertilization with neat

diagram.

The fusion of male and female gametes is

known as fertilization.

After landing of the pollen grains on

the surface of stigma they starts germinating

and produce pollen tubes. One of the pollen

tubes continues to develop downwards in to a

style. This pollen tube carries the male gametes.

This pollen tube finally reaches the ovary.

When this reaches the ovule, the male gametes

are released from the pollen tube and fuse with

the female gametes located inside the ovule and

produce a zygot. After fertilization the ovary

becomes larger and develops in to a fruit and the ovule develops in to a seed.

3. Describe pericarp and its different parts.

The pericarp is the fruit wall, which develops from the wall of the ovary.

It may be thick and thin depending on the kind of fruit. It is soft and

fleshy in some fruits like tomato and papaya and it is dry in gram.

The pericarp has three part.

Epicarp: This is the thin outer protective covering of the fruit.

Mesocarp: This is the sweet, fleshy, edible middle layer of the fruit.

Endocarp: It is the inner hard part of the fruit, which contains seeds.

4. What is the difference between a fleshy fruit and a dry fruit?

In a fleshy fruit the entire pericarp is soft and fleshy. The endocarp is

hard and contains the seeds. Example- grape, tomato, papaya etc.

In a dry fruit the pericarp is not pulpy and fleshy, it encloses the seeds.

Example – in a pea pod the pod is the pericarp and the pea is the

seed which is enclosed within the pod.

5. With the help of suitable diagram describe the structure of a monocot

seed.

The maize grain has one

cotyledon, hence it is said to

be a monocot seed.

It is triangular in shape. The lower

end of the seed is narrow and is

yellowish white. The upper end

of the seed is wide and is dark

yellow in colour.

The seed coat of the maize grain is fused with the pericarp.

The upper larger part is called the endosperm. It stores the food and

surrounded by a protein rich layer called Aleurone layer. The lower part

of the seed is called cotyledon. It contains the embryo which is made

up of the radicle and plumule.

6. Write the difference between a bean seed and a Maize grain

Bean Seed	Maize Grain
Dicot seed	Monocot seed
Endosperm is absent	Endosperm is present
Cotyledons store food	Endosperm stores food.
Embryo is large	Embryo is small
Seed is contained separately in a fruit.	Seed coat and the fruit wall are fused to form a grain.

7. Write short notes on the following.

i) Radicle ii) Plumule iii) Embryo iv) Cotyledon v) Endosperm

i) Radicle: The radicle is part of embryo inside the seed which first come

out during the seed germination and develops in to the root of a plant.

ii) Plumule: The plumule is the portion of the plant embryo which gives

rise to the first leaves and form the shoot system of the plant during

germination.

iii) Embryo: Embryo is the baby plant inside the seed, which contains the

radicle and plumule. It is the early stage of the plant and gradually

develops after germination.

iv) Cotyledons: The cotyledons provide food for the embryo during the

germination in dicot plants. They act as leaves and perform

photosynthesis in the beginning.

v) Endosperm: It is present in the monocot seed and stores food in the

form of starch, which helps the seedling for growth.

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Class 6 - Biology - The Flower - Exercise And Solutions

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