ICSE Class 7 Biology Important Questions Chapter 4 Movement in Animals and Plants

Biology ICSE Class 7 Important Questions Chapter 4 Movement in Animals and Plants

Extra Questions

Question 1.
Name the kind of locomotion shown by –

1. Amoeba
2. Paramecium
3. Euglena

Answer:

1. Amoeboid locomotion
2. Ciliary locomotion
3. Flagellar locomotion

Question 2.
What is gliding flight in birds ?
Answer:
In gliding flight, the wings are held stretched sidewards without flapping. The air pressure above them is lower than the air pressure underneath. This provides a thrust that prevents birds from falling and enables the bird to glide slightly downward or gain height depending upon the prevailing air current.

Question 3.
Name two types of flights shown by birds.
Answer:
(a) Flapping flight
(b) Gliding flight

Question 4.
Name the main organ of locomotion in –

1. aquatic mammals
2. Terrristrial mammals

Answer:

1. Aquatic mammal like whale and seal have fin-like flippers (modified limbs) for swimming.
2. Terristrial mammals use two pairs of limbs (forelimbs and hindlimbs) like tigers, cows,’ etc or hind legs like humans, some apes, kangaroos, etc for locomotion.

Question 5.
What is the skeletal system made of ?
Answer:
Bones, joints connective tissue (cartilage, tendons and ligaments) and muscles.

Question 6.
Name the types of joints present in the human body.
Answer:

Question 7.
Why are movable joints also called as synovial joints?
Answer:
It is due to the presence of a lubricating fluid called synovial fluid. Synovial fluid enables the smooth movement of bones at the joints.

Question 8.
Write brief note on various types freely movable joints in the human body.
Answer:
Ball-and-socket joint – It allows movement of bones in almost all directions. The end of one bone is rounded (called ball), which fits into the hollow parts of the other bone (called socket).
Examples : The shoulder and hip joints.

Hinge Joint – It allows movement in only one direction.

The protruded end of one bone bone moves in the depressed surface of another bone, similar to the movement of a door on its hinges.
Examples : The knee and elbow joints.

Pivot Joint – It allows rotating movement from side to side. In this joint, a rounded or conical surface of one bone moves within a ring formed partly by another bone and partly by a ligament.
Examples : Joint between the first and second vertebrae in the neck and the elbow joint which enables sideways
movement

Gliding joint – It allows only sideways and back and forth movement between two flat bones.

Examples : Some bones of the wrist and ankles have these joints.

Question 9.
What is a flexor muscle and an extensor muscle ?
Answer:
A muscle that contracts and pulls the body part towards the body is called a flexor muscle. Example : Bicep muscle. A muscle that contracts and straightens the body part and moves it away from the body is called an extensor muscle,  Example : Tricep muscle.

Question 10.
Differentiate between thigmotropism and hydrotropism.
Answer:
Thigmotropism :

1. It is the growth in response to stimulus of touch.
2. Climbing or twining of plants such as grapes around solid objects like tree trunks.

Hydrotropism :

1. It is the response of parts of a plant towards moisture.
2. Growth of roots towards moisture (positively hydro-tropic) or growth of a plant part away from moisture (negatively hydrotropic)

Question 11.
Differentiate between geotropism and phototropism.
Answer:
Geotropism :

1. It is the response of plant part towards the force of gravity.
2. Roots are positively geotropic
3. Stems are negatively phototropic.

Phototropism :

1. It is the movement of a plant part in response to light.
2. Roots are negatively phototropic
3. Stems are positively geotropic.

Question 12.
Fill in the blanks.
(i) The wings in birds and bats are modified …………
Answer:
The wings in birds and bats are modified forelimbs.

(ii) ………… are the only mammals that can fly.
Answer:
Bats are the only mammals that can fly.

(iii) Animals such as human beings that walk on two legs are called …………
Answer:
Animals such as human beings that walk on two legs are called bipeds

(iv) Most mammals walk on four legs and are called …………..
Answer:
Most mammals walk on four legs and are called tetrapods or quadruped.

(v) The human skeleton is made up of …………… bones
Answer:
the human skeleton is made up of 206 bones

(vi) ………… cells are the only cells in the body that can contract or shorten and relax or lengthen.
Answer:
Muscle cells are the only cells in the body that can contract or shorten and relax or lengthen.

(vii) Muscles always move bones by …………. and not by relaxing.
Answer:
Muscles always move bones by contracting and not by relaxing.

(viii) …………. movements in plants are movements in response to direction.
Answer:
Tropic movements in plants are movements in response to direction.

(ix) …………. movements in plants are movements in response to environmental stimulus.
Answer:
Nastic movements in plants are movements in response to environmental stimulus.

(x) Skeletal muscless work in pairs but in opposite direction and are also called ………… muscles.
Answer:
Skeletal muscless work in pairs but in opposite direction and are also called antagonistic muscles.

Practice Question 1.
What are the organs of locomotion in Paramecium ?
Answer:
Hair like structures called cilia are present around the body of Paramecium. Cilia helps in moving by repeated lashing movements against the water. This type of movement is called ciliary locomotion, which helps the paramecium in forward and backward movements.

Ciliary locomotion in Paramecium

Practice Question 2.
How does a bat move ?
Answer:
Bats move with the help of modified forelimbs. The forelimbs of bat have been modified in to wings for flying. The skin is stretched like a membrane between the elongated fingers, and hind legs and tail forming an umbrella like shape. The fingers act like ribs, that help in opening and closing of membrane.

Forelimbs of bats are modified into wings for flying.

ICSE Class 7 Biology Important Questions