Living Science Biology Class 6 ICSE Solutions Chapter 5 The Structure and Functions of Plant Parts

ICSE Living Science Biology for Class 6 Solutions Chapter 5 Tne structure ana Functions of Plant Parts

Check Your Progress

Fill in the blanks.
Question 1.
The ends of primary or secondary roots have fine hair-like structures, called …………
Answer:
The ends of primary or secondary roots have fine hair-like structures, called root hair.

Question 2.
Fibrous roots are found in and …………..
Answer:
Fibrous roots are found in grass and wheat plant.

Question 3.
………… fix the plant firmly to the soil.
Answer:
Roots fix the plant firmly to the soil.

Question 4.
Banyan trees have ………… roots which provide support to heavy branches.
Answer:
Banyan trees have prop roots which provide support to heavy branches.

Question 5.
………… roots help in absorbing nutrients from the body of the host.
Answer:
Sucking roots help in absorbing nutrients from the body of the host.

Practice Question 1.
is an enlarged, roughly spherical-shaped stem storing food.
Answer:
Tuber is an enlarged, roughly spherical-shaped stem storing food.

Practice Question 2.
The region between two successive nodes of a stem is called …………
Answer:
The region between two successive nodes of a stem is called internode.

Check Your Progress

State if the following statements are true or false. Correct the statement if it is false.

Question 1.
The point on the stem from where leaves and branches arise is called Internode.
Answer:
False. The point on the stem from where leaves and branches arise is called node.

Question 2.
A growth in a terminal bud leads to an increase in the length of the stem.
Answer:
True

Question 3.
Rhizome is an enlarged, roughly spherical-shaped stem that stores food.
Answer:
False. Tuber is an enlarged, roughly spherical-shaped stem that stores food.

Question 4.
The region between two successive nodes of a stem is called node.
Answer:
False. The region between two successive nodes of a stem is called intemode.

Check Your Progress
State if the following statements are true or false. Correct the statement if it is false.

Question 1.
The lamina has a thickened vein along its centre called veinlet.
Answer:
False. The lamina has a thickened vein along its centre called midrib.

Question 2.
In reticulate venation, veins and veinlets are irregularly distributed over the entire lamina, forming a network.
Answer:
True

Question 3.
In a simple leaf, the leaf blade is clearly divided into many distinct parts called leaflets.
Answer:
False. In a compound leaf, the leaf blade is clearly divided into many distinct parts called leaflets.

Question 4.
In alternate arrangement, a set of three or more leaves grows from the same node.
Answer:
False. In whorled arrangement, a set of three or more leaves grows from the same node.

Question 5.
Leaf spines help to reduce the loss of water by transpiration.
Answer:
True

A. Tick the most appropriate answer.

Question 1.
Which of the following is not a function of the roots ?
a. To absorb water and minerals
b. To anchor the plant to the soil
c. To store food
d. To manufacture food
Answer:
d. To manufacture food

Question 2.
A flower is borne on a short stalk called –
a. petiole.
b. filament.
c. pedicel.
d. plumule.
Answer:
c. pedicel.

Question 3.
Which of the following roots give mechanical support to the plant ?
a. Prop roots
b. Ephiphytic roots
c. Nitrogen-fixing roots
d. Breathing roots
Answer:
a. Prop roots

Question 4.
The point on the stem where its leaves arise is –
a. internode.
b. node.
c. bark.
d. trunk.
Answer:
b. node.

Question 5.
The wide, thin, flat part of the leaf is called –
a. lamina.
b. petiole.
c. vein.
d. midrib.
Answer:
a. lamina

Question 6.
The calyx consists of –
a. sepals.
b. stamens,
c. anthers.
d. petals.
Answer:
a. sepals.

Question 7.
The gynoecium consists of –
a. stigma and anthers.
b. anthers and filaments.
c. stigma, pollen grains and ovary.
d. stigma, style and ovary.
Answer:
d. stigma, style and ovary.

Question 8.
Which part of a flower gives rise to the seeds ?
a. Pollen grains
b. Ovary
c. Ovules
d. Stigma
Answer:
c. Ovules

Practice Question 1.
Flowers with either male or female reproductive part arc –
a. bisexual.
b. hermaphrodite.
c. unisexual.
d. none of these
Answer:
c. unisexual.

Practice Question 2.
The transfer of pollen grains from the anther to the stigma is termed as –
a. fertilization.
b. reproduction,
c. fusion.
d. pollination.
Answer:
d. pollination.

B. Fill in the blanks.

Question 1.
Primary root is at its origin and ………… at the tip.
Answer:
Primary root is broad at its origin and thin at the tip.

Question 2.
………….. are the additional roots that arise from the lower part of the stem and fix the plant firmly in the ground.
Answer:
Stilt are the additional roots that arise from the lower part of the; stem and fix the plant firmly in the ground.

Question 3.
Plants with brightly coloured flowers are usually pollinated by …………
Answer:
Plants with brightly coloured flowers are usually pollinated by insects.

Question 4.
Cone shaped roots that grow vertically upwards and come out of the ground are known as ………….
Answer:
Cone shaped roots that grow vertically upwards and come out of the ground are known as pneumatophores.

Question 5.
…………. is an enlarged, roughly spherical-shaped stem storing food.
Answer:
Tuber is an enlarged, roughly spherical-shaped stem storing food.

In a …………. leaf the leaf blade is clearly divided into many distinct parts.
Answer:
In a compound leaf the leaf blade is clearly divided into many distinct parts.

Practice Question 1.
A flower usually has four parts – calyx, corolla and ………….
Answer:
A flower usually has four parts – calyx, corolla androecium and gynoecium.

Practice Question 2.
Reproduction is a two step process. The first step is called …………. and the second step is called …………
Answer:
Reproduction is a two step process. The first step is called pollination and the second step is called fertilisation.

Practice Question 3.
Fruit is nothing but a ripened …………
Answer:
Fruit is nothing but a ripened ovary.

Practice Question 4 .
A fruit may have one seed, as in as in ……….. or many seeds,
Answer:
A fruit may have one seed, as in mango or many seeds, as in apple.

C. Match the following.

Definition	Terms
1. part of the flower that produces pollen grains	a. petiole
2. green leaf-like structure protecting the inner parts of flower	b. anther
3. root system where side roots develop from a main primary root	c. ovules
4. fusion of the male reproductive cell with the egg cell	d. calyx
5. parts of a flower that develops into seeds	e. tap root
6. points on the stem at which leaves arise	f. internodes
7. ripened ovules	g. fertilization
	h. seeds
	i. nodes

Answer:

Definition	Terms
1. part of the flower that produces pollen grains	b. anther
2. green leaf-like structure protecting the inner parts of flower	d. calyx
3. root system where side roots develop from a main primary root	e. tap root
4. fusion of the male reproductive cell with the egg cell	g. fertilization
5. parts of a flower that develops into seeds	c. ovules
6. points on the stem at which leaves arise	i. nodes
7. ripened ovules	h. seeds

D. State if the following statements are true or false. Correct the statement if it is false.

Question 1.
The node is the part of the stem between two ihternodes.
Answer:
False : The intemode is the part of the stem between two nodes.

Question 2.
Anther, style and stigma are the parts of a pistil.
Answer:
False : Ovary, style and stigma are the parts of a pistil.

Question 3.
A stamen has a long stalk called style.
Answer:
False : A stamen has a long stalk called filament.

Question 4.
The transfer of the pollen grains from the anthers to the stigma of a flower is called fertilization.
Answer:
False : The transfer of the pollen grains from the anthers to the stigma of a flower is called pollination.

Question 5.
The leaves of Opuntia are modified into thorns.
Answer:
True.

Practice Question 1.
Ovules develop into fruits.
Answer:
False : Ovules develop into seeds.

Practice Question 2.
The stem helps in absorbing water from the soil.
Answer:
False : The root helps in absorbing water from the soil.

Practice Question 3.
The flat green portion of the leaf is called the leaf blade.
Answer:
True.

Practice Question 3.
Mango and orange are fruits whereas cucumber and tomato are vegetables.
Answer:
False : Mango and orange are fruits whereas cucumber and tomato are also fruits.

Practice Question 4.
Cluster of roots of about the same size are present in the fibrous root system.
Answer:
True.

E. Find the odd one out. Give reasons.

Question 1.
stem, leaves, root, flowers
Answer:
root: stem, leaves and flowers are a part of shoot system whereas root forms the root system of a plant.

Question 2.
calyx, corolla, stamen, stem
Answer:
stem : stem is a part of a plant whereas calyx, corolla and stamen are parts of a flower.

Question 3.
ovules, lamina, midrib, petiole
Answer:
ovules : ovules are a part of gynoecium whereas the other three are parts of a leaf.

Question 4.
leaf, stigma, style, ovary
Answer:
leaf: leaf is a part of plant whereas stigma, style and ovary are parts of female reproductive part of a plant (carpel).

F. Name the type of stem present in the following.
1. Potato
2. Onion
3. Ginger
4. Cactus
Answer:
1. Potato – Tuber
2. Onion – Bulb
3. Ginger – Rhizome
4. Cactus – Phylloclade

G. State the functions of the following.
1. Leaf spines
2. Stem tendril
3. Phylloclade
4. Stilt roots
Answer:
The functions of:
1. Leaf spines : They help to reduce the loss of water by transpiration. They also help to protect the plant from the grazing animals, e.g. Cactus, mexican poppy.
2. Stem tendril : These stems provide support to the plant by coiling around some wall, tree etc. and helping the plant to climb, e.g. Passion flower, grapevine.
3. Phylloclade : These modified stems in desert plants carry out the function of preparation and storage of food. They fleshy stems also store water to be used in long dry periods, e.g. Opuntia.
4. Stilt roots: They fix the plant firmly to the soil in plants where the stem is weak and tall. They arise from the lower part of the stem.

H. We eat different parts of various plants. For each plant, write the part of the plant that we eat.
1. carrot …………..
2. cucumher …………..
3. radish …………..
4. tomato …………..
5. onion …………..
6. potato …………..
7. ginger …………..
8. sugar cane …………..
9. lady’s finger …………..
10. mint …………..
11. fenugreek …………..
12. pea …………..
13. apple …………..
14. groundnut …………..
Answer:
1. carrot – roots
2. cucumber – fruit
3. radish – roots
4. tomato – fruit
5. onion – stem
6. potato – stem
7. ginger – stem
8. sugar cane – stem
9. lady’s finger – fruit
10. mint – leaves
11. fenugreek – leaves
12. pea – seed
13. apple – fruit
14. groundnut – seed

I. Differentiate between :
1. cross pollination and self pollination
2. reticulate venation and parallel venation
3. terminal bud and axillary bud
4. simple leaf and compound leaf

Practicle Question 1.
prop roots and pneumatophores
Answer:
Differentiate between :
1. Cross pollination : The pollination where the pollen grains are transferred from the anthers of a flower of one plant to the stigma of a flower of another plant but of same type, it is called cross pollination, e.g. Cherry plant, apple plant, pear plant.

Self pollination : In self pollination, pollen grains are either transferred from the anthers to the stigma of the same flower or from anthers of a flower to the stigma of another flower of the same plant, e.g. Peanut plant, pea plant, sunflower plant.

2. Reticulate venation : In this type of venation, veins on the leaf lamina are arranged in a net like pattern, e.g. Leaves of mango and rose plant.
Parallel venation : In parallel venation, veins on the leaf lamina run parallel to each other in a leaf. e.g. Leaves of banana plant, coconut leaf.

3. Terminal bud :
a. The buds that grow at the tips of the stems or its branches are called terminal or apical buds.
b. They lead to an increase in the length of the stem.

Axillary bud :
a. These buds are present in the axil of a leaf i.e. between a leaf and a stem.
b. They .give rise to new branches.

4. Simple leaf : A leaf with single undivided leaf blade is called a simple leaf. e.g. Peepal, mango.
Compound leaf : The leaf blade of a compound leaf is divided into many leaflets, e.g. Neem, palm trees.

Practicle Question 2.
Prop roots and pneumatophores
Prop roots :
a. Prop roots are modified aerial roots that grow vertically downward from the branches to reach deep into the soil.
b. These roots provide additional support to the heavy branches of a plant.
c. e.g. Banyan tree.

Pnematophores :
a. These are cone shaped roots that grow vertically upwards and come out of the ground.
b. These roots have pores on them and help the plants in water logged areas to take in air i.e. respire.
c. e.g. Mangroves.

J. State the agents of pollination for each of the following.
1. Sunflower
2. China rose
3. Rose
4. Maize
5. Jasmine
6. Hydrilla
Ans. 1. Sunflower – Insects
2. China rose – Insects
3. Rose – Insects
4. Maize – Wind
5. Jasmine – Insects
6. Hydrilla – Water

K. Answer the following in short.

Question 1.
Give one example of modification of roots.
Answer:
Roots of some plants get modified to store food and look swollen, e.g. Roots of radish and carrot.

Question 2.
What are prop roots ?
Answer:
Prop roots are modified aerial roots that grow vertically downward from the branches in plants like banyan tree. These roots
reach deep into the soil and provide additional support to the heavy branches.

Question 3.
What is a rhizome ?
Answer:
Rhizomes are modified swollen stems that grow horizontally under the ground. They store food for the plant, e.g. ginger, turmeric.

Question 4.
What is pollination ?
Answer:
The transfer of the pollen grains from the anthers to the stigma of a flower is called pollination. It is the first step of reproduction in flowers. It takes place through self pollination or cross pollination.

Question 5.
What is fertilization ?
Answer:
Fertilization means the fusion of a male cell with a female cell (egg cell) to produce one single cell called zygote. In plants, after the fertilization the ovules grow into seeds and the ovary develops into the fruit.

Question 6.
Why are pollen grains produced in large quantity in wind-pollinatd flowers ?
AnswerPollen grains pollinated by winds are produced in large quantity since a large number of pollen grains may not reach the stigma of a flower.

Question 7.
What is venation ? State its various types.
Answer:
The arrangment of veins and veinlets on the lamina of a leaf is called venation.
The venation is of two types :
a. Parallel venation : Veins run parallel to each other. e. g. Leaves of banana, grass.
b. Reticulate venation : Veins are arranged like a network, e.g. Leaves of mango, guava.

L. Answer the following in detail.

Question 1.
State any three functions of the root ?
Answer:
Functions of the roots are :
a. They fix the plant firmly to the soil.
b. They absorb water and minerals from the soil and transport it to the leaves through stem for manufacturing of food.
c. Roots help in holding the soil together and prevent soil erosion.
d. In some modified roots, they perform the function of storing food. e.g. Radish, carrot.
e. Roots can also help in respiration in certain plants like mangroves.

Question 2.
How is a tap root different from a fibrous root ?
Answer:
Tap root: This root has one main primary root with many side secondary’ roots, e.g. Mango, pea.

Fibrous root : These roots are clusters vi same thickness and size roots arising from the base of the stem. e.g. maize, wheat.

Question 3.
What are the main parts of a leaf ?
Answer:
A leaf has following main parts :

a. Leaf stalk or petiole – It joins the leaf with the stem of the plant.
b. Leaf base – The point where leaf is attached to the stem.
c. Lamina or leaf blade – Flat, green, expanded portion of the leaf.
d. Midrib – Petiole extends into the leaf along its centre as the midrib. Many veins arise from it.

Question 4.
What is a fruit ? State its function.
Answer:
Fruit is nothing but a ripened ovary, formed after fertilization
in a plant. It’s functions are :
a. It protects the immature seeds from animals and extreme climatic conditions.
b. It stores food material.
c. It helps in the dispersal of seeds by attracting animals.

Question 5.
Draw a flowering plant and label all its parts.
Answer:

Question 6.
Describe the special characteristics of flowers pollinated by insects.
Answer:
Flowers pollinated by insects show certain special characteristics like:
a. They have brightly coloured petals to attract insects. e. g. Rose and marigold.
b. They produce nectar so that when insects suck it, they carry pollen grains with them. e.g. Honeybee.
c. Most of them are sweet smelling to attract insects, e.g. Jasmine.
d. Pollen grains and the stigma of most of these flowers are sticky.

Question 7.
Wind pollinated flowers produce light and dry pollen grains. Why ?
Answer:
Wind pollinated flowers produce pollen grains which are light and dry so that they may easily be carried away by the gentlest breeze for dispersal.

Question 8.
What are the various adaptations seen in seeds dispersed by animals ?
Answer:
The various adaptation in seeds dispersed by animals are :
a. Some projections like hooks, barbs, spines, bristles and stiff hair are present on the surface of seeds which get attached to the skin of animals and carried to distant places and hence dispersed.
b. Seeds are embedded in fleshy and edible fruits in some plants that attract animals to eat them.
c. The seed itself can also become an attractive food for animals like squirrels and acorns.

Practcle Question 1.
Write two important functions of the stem.
Answer:
Two important functions of the stem are :
a. Stem bears all the aerial parts like leaves, flowers and fruits.
b. It conducts water and minerals upwards i. e. from roots to the leaves and transports food from leaves to all parts of the plant.

Practcle Question 2.
Why are seed produced in large quantity ?
Answer:
Seeds are produced in large quantity because not all of them grow into plants. So to ensure that at least a few of them end in a favourable place for growth, plants produce more seeds than will ever become adult plants. If they don’t overproduce, the specie would die out.

Practcle Question 3.
What are the different agents of seed dispersal ?
Answer:
The different agents of seed dispersal are :
a. Wind : e.g. Cotton plant disperses its pollens into the air.
b. Insects : e.g. Lavender plant attracts bees to transmit their pollens from one flower to the next.
c. Water: e.g. Coconut fruit floats and gets carried away by water.
d. Animals: e.g. Hibiscus plant is pollinated by humming birds.

Practcle Question 4.
State various adaptations in the seeds dispersed by wind.
Answer:
The seeds dispersed by wind have fluff or tufts of hair or wings to be easily dispersed by wind. Seeds of some plants are so light that they get easily carried away by the slightest wind to long distances.

M. Give reasons for the following.

Question 1.
The leaves of prickly pear are reduced to spines.
Answer:
Leaves reduced to spines in prickly pear reduce the loss of
water by transpiration. Spines also protect the plant from the grazing animals.

Question 2.
Insect-pollinated flowers have brightly coloured petals and have stickly pollen grains.
Answer:
Brightly coloured petals attract insects which help in pollination. The stickly pollen grains get stuck to the body parts of insects when they visit them to collect nectar. When insects visit another flower, pollen grains get transferred to the stigma of that flower.

Question 3.
A tomato and an orange are both fruits.
Answer:
Tomato and orange are both fruits as they are repened ovaries, (whereas a vegetable can be any part of a plant)

N. Given alongside is a figure of a flower.

Copy the diagram in your notebook and label the following parts, thalamus, style, stigma, sepals, petals and stamens

Answer:

Living Science Biology Class 6 ICSE Solutions