Question

Write answers to the following.
(a) What are the parts of a plant ?
(b) What are the functions of the root ?
(c) Why is it necessary to classify living things ?
(d) What are the criteria used to classify living things ?
(e) Tell some characteristics of creepers.
(f) Explain the characteristics of herbs with two examples.
(g) On the basis of which criteria will you classify plants and animals ?
(h) What protects the bodies of animals?

Answer 1

Ans 6 a. The various parts of a plants are:

• Roots: They absorb water and minerals from the soil and also anchor the plant firmly in the soil.
• Stems: Spread out branches to bear leaves, flowers and fruits, conducts water and minerals to different plant parts and performs functions of storage, support, protection and vegetative propagation.
• Leaf: They are called ‘food factories’ of a plant. They carry out photosynthesis, a process by which they synthesize their food.
• Flower: In plants, flower is the functional unit concerned with the sexual reproduction of plants.
• Fruits: They have different shapes and contain one or more seeds.

b. The functions of the roots are as follows:

• they help in anchoring the plant to the soil.
• they also help in the absorption of water and nutrients from the soil.

c. Importance of classification:

(i) Classification ensures uniformity. All life forms can be studied on a common platform.

(ii) Classification ensures the study of interrelationship between various groups.

(iii) It helps us to study many organisms at same time.

d. Organisms can be classified on the basis of similarities and differences in their structure, their organs and other characteristics.


e. Plants which cannot stand upright, and spread on the ground are called creepers. They show characteristics like:

• their stem is very flexible, soft and green
• it grows rapidly with the help of a support

f. Herbs have the following characteristics:

• they grow upto the size 1-1.5 metres
• they have green and flexible stems
• they can live upto few months or upto two years
• examples of herbs include tulsi, parsley, mint etc.

g. Plants and animals are classified on the basis of different characteritics:

Plants are classified on the basis of

• height
• shape of stems
• period of life cycle
• habitat

Animals are classified on the basis of:

• cell structure
• vertebral coloumn
• method of reproduction
• habitat

h. There are different mechanisms by which animals protect themselves from danger such as their predators:

• Some organisms are covered by hard shells to protect themselves. For example, garden snail, tortoise etc. have a heard shell which they use to hide themselves under danger conditions.
• Star fish and porcupines have spines on their surface which they can use against their enemies.
• Organisms like chameleon and frogs can change their colours according to the surrounding environment. It is known as chamouflaging.
• Animals which are found in very cold regions have a thick layer of fat under the skin and thick fur to protect them from extreme cold conditions.