Living Science Biology Class 6 ICSE Solutions Chapter 3 Classification of Plants

ICSE Living Science Biology for Class 6 Solutions Chapter 3 Classification of Plants

Check Your Progress

State if the following statements are true or false. Correct the statement if it is false.
Write True of False.

Question 1.
Spirogyra and Volvox are examples of bryophytes.
Answer:
False. They are examples of algae.

Question 2.
Bryophyta includes only mosses.
Answer:
False. Bryophyta includes mosses and liver worts.

Question 3.
Bryophytes have root-like structures called rhizoids instead of roots.
Answer:
True.

Question 3.
Instead of roots, mosses have rhizoids.
Answer:
True.

Question 4.
The leaves of pteridophytes are called fronds.
Answer:
True.

Question 5.
The lower side of the leaves of ferns bear sori.
Answer:
True.

A. Tick the most appropriate answer.

Question 1.
An example of a flowering plant is –
a. fern.
b. yeast.
c. Spirogyra.
d. rice.
Answer:
d. rice.

Question 2.
Well-developed roots, stem and leaves are present in –
a. bryophytes and algae.
b. algae, bryophytes and angiosperms.
c. algae, bryophytes and gymnosperms.
d. ferns, gymnosperms and angiosperms.
Answer:
d. ferns, gymnosperms and angiosperms.

Question 3.
Biennials complete their life cycle in –
a. two years.
b. one year,
c. three years.
d. ten years.
Answer:
a. two years.

Question 4.
Plants that grow and thrive in water are called –
a. mesophytes.
b. hydrophytes.
c. xerophytes.
d. none of these
Answer:
b. hydrophytes.

Question 5.
Parasites and saprophytes belong to group –
a. autotrophs.
b. homotrophs.
c. heterotrophs.
d. none of these.
Answer:
c. heterotrophs.

B. Fill in the blanks.

Question 1.
……………. are green plants that contain chlorophyll and usually live in stagnant water.
Answer:
Algae are green plants that contain chlorophyll and usually live in stagnant water.

Question 2.
Bryophytes have …………… instead of roots.
Answer:
Bryophytes have rhizoids instead of roots.

Question 3.
The leaves of ferns are called …………
Answer:
The leaves of ferns are called fronds.

Question 4.
In ………….. the seeds are not enclosed in a fruit.
Answer:
In gymmosperms, the seeds are not enclosed in a fruit.

Question 5.
Cuscuta is a –
Answer:
Cuscuta is a parasitic plant.

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

Question 1.
Bryophytes grow in dry arms.
Answer:
False : Bryophytes grow in moist areas.

Question 2.
Pteridophytes grow in damp and shady areas.
Answer:
True.

Question 3.
Plants that have seeds in cones are called ferns.
Answer:
False: Plants that have seeds in cones are called gymnosperms.

Question 4.
Dicotyledonous plants have seeds with two cotyledons.
Answer:
True.

Question 5.
Perennial plants continue to grow and produce seeds every year.
Answer:
True.

D. Differentiate between

1. gymnosperms and angiosperms
2. annuals and perennials
3. xerophytes and hydrophytes

Practice Question 1.
flowering plants and non-flowering plants
Answer:
Gymnosperms and angiosperms
Gymnosperms:
a. These plants bear naked seeds called cones.
b. They usually have needle like leaves.
c. They usually remain green throughout the year.
d. e.g. Pine, Cycas cedar.

Angiosperms:
a. These plants bear seeds enclosed inside a fruit.
b. They usually have normal flat leaves.
c. They usually shed their leaves every autumn.
d. e.g. Rose, apple, mango.

2. Annuals and perennials
Annuals :
a. These plants complete their life cycled one year.
b. These plants germinate, flower and produce seeds within a season.
c. e.g. Maize, wheat, rice.

Perennials :
a. These plants live for many years.
b. They continue to grow and produce flowers for many years.
c. e.g. Mango, banyan, neem.

3. Xerophytes and hydrophytes
Xerophytes
a. These are plants that grow on dry land like deserts where there is scarcity of water.
b. Leaves are reduced to spines to minimise the loss of water.
c. Roots are long and reach deep layers of the soil.
d. e.g. Cactus, babul.

Hydrophytes :
a. These plants need maximum water to grow and hence live in water.
b. Leaves have a waxy coating to protect themselves from water.
c. Roots are very reduced as water is available in plenty.
d. e.g. Hydrilla, lotus.

Practice Question 2.
flowering plants and non-flowering plants
Flowering plants
a. Flowering plants bear seeds and fruits.
b. They are also called as phanerogams.
c. They are fiirther divided into gymnosperms and angjosperms.
d. e.g. Mango plant, wheat plant.

Non-flowering plants:
a. Non-flowering plants do not produce flowers and seeds.
b. They are also called as cryptogams.
c. They are further divided into Bryophyta, Thallophyta and Pteridophyta.
d. e.g. Ferns, mosses, mushroom.

E. Write short answers to the following questions.

Question 1.
What are cryptogams ?
Answer:
Cryptogams are non-flowering plants which do not produce seeds and flowers. They are further categorised into Thallophyta (Algae, Bacteria, Fungi), Biyophyta (Mosses) and Pteridophyta (Ferns).

Question 2.
State the groups into which plants are classified on the basis of seed-bearing nature.
Answer:

Seed bearing plants are called phanerogams.
Non-seed bearing plants are called cryptogams.

Question 3.
What are bryophytes ?
Answer:
Bryophytes are those non-flowering plants which grow on moist land and need water to reproduce. They are also called the amphibians of the Plant Kingdom, e.g. Mosses, liverworts.

Question 4.
What are characteristics of pteridophytes ?
Answer:
Characteristics of pteridophytes (ferns) are:
(a) These are non-flowering plants which do not produce seeds.
(b) These plants grow in damp and shady areas.
(c) The leaves are feather like and called fronds. (Pteron means feather and phyton means plants). They are divided into leaflets.
(d) They reproduce through spores bom on the lower side of fronds in small rounded brown structures called sori.
(e) The plants either have underground stems called rhizome or stems above the ground.

Question 5.
Give two important features of angiosperms.
Answer:
Two important features of angiosperms are:
(a) Thfey are plants with well-developed roots, stem, leaves and flowers.
(b) They produce seeds which are enclosed in a fruit.

Practice Question 1.
What is the basis of classification of plants into flowering plants and non-flowring plants ?
Answer:
The presence or absence of flowers and seeds in a plant forms the basis of classification of plants into flowering plants (Cryptogams) and non-flowering plants (Phanerogams).

Practice Question 2.
Why biyophytes are called amphibians of plant kingdom?
Answer:
Since bryophytes grow on land but need water for reproduction (like frogs in animals), they are called the amphibians of plant kingdom.

F. Answer the following in detail.

Question 1.
How are herbs, shrubs and trees different from each other? Explain giving examples.
Answer:
Depending on the size, plants are classified into three groups :
(a) Herbs : They are veiy small plants with soft and green Stems. Eg. Mint, spinach.
(b) Shrubs : They are medium sized plants with woody stems. The branches are almost same size arising from the stem immediately above the soil. e.g. Rose, jasmine.
(c) Trees : Tall plants with a thick, hard and woody stem are called trees. They bear woody branches and leaves at some distance above the ground, e.g. Coconut, mango.

Question 2.
Classify plants on the basis of (i) their habitats and (ii) their life span.
Answer:
(i) On the basis of a place where a plant grows (its habitat), plants are classified into three groups:
(a) Mesophytes : Plants which grow on land and need moderate amount of water, e.g. Potato, tomato.
(b) Hydrophytes : Plants that need maximum water-to grow and hence live in water. They may be floating or partially/completely submerged, e.g. Lotus, Hydrilla.
(c) Xerophytes : Plants that grow on diy land like deserts and need minimum amount of water to live. They have ] tliin and spiny leaves to reduce water loss. e.g. Cactus, babul.

(ii) On the basis of time taken to complete their life cycle, plants are divided into three groups :
(a) Annuals : These plants complete their life cycle in one season in a year. e.g. Wheat, rice.
(b) Biennials : These plants complete their life cycle in two years i.e. in the first year, they bear root, stem and leaves and in the second year, they produce flowers, fruits and seeds, e.g. Carrot, radish, turnip.
(c) Annuals : These plants life for more than two years and bear flowers, fruits and seeds every year. e.g. Mango, Banyan.

Question 3.
Write a short note on gymnosperms.
Answer:
Gymnosperms are plants having naked seeds, i. e., seeds are not enclosed in fruits. The seeds are borne on woody structures called cones, and hence called conifers or coniferous trees. They produce male and female cones for reproduction instead of flowers. Gymnosperms are mostly tall trees growing on mountains. They have well developed roots, thick and woody stems and long needle-shaped leaves. They are evergreen plants.
Examples : Pine, cycas, cedar, Ginkgo, spruce, etc.

G. Classify the given plants into categories that are indicated.

Question 1.
Cedar, neem, banana, pine, Cycas, marigold, Petunia, Juniper, fig, orange, Ginkgo into gymnosperms and angiosperms.
Answer:
Gymnosperms – Angiosperms
Cedar, pine – Neem, banana ‘
Cycas, juniper – Marigold, Petunia
Ginkgo – Fig, orange

Question 2.
Hydrilla, Opqntia, babul, rose, water lily, lotus, Vallisneria into mesophytes, hydrophytes, xerophytes.
Answer:
Living Science Biology Class 6 ICSE Solutions Chapter 3 Classification of Plants Extra - 1

Question 3.
Eucalyptus, mint, rose, spinach, neem, radish, tulsi, banana and china rose into herbs, shrubs and trees.
Answer:
Living Science Biology Class 6 ICSE Solutions Chapter 3 Classification of Plants Extra - 2

Question 4.
Mango, carrot, poppy, apple, oak, mint, cabbage, radish and turnip into annuals, biennials and perennials.
Answer:
Living Science Biology Class 6 ICSE Solutions Chapter 3 Classification of Plants Extra - 3