RBSE Solutions for Class 11 Biology Chapter 20 Locomotion and Movement

Rajasthan Board RBSE Solutions for Class 11 Biology Chapter 20 Locomotion and Movement Textbook Exercise Questions and Answers.

Rajasthan Board RBSE Solutions for Class 11 Biology in Hindi Medium & English Medium are part of RBSE Solutions for Class 11. Students can also read RBSE Class 11 Biology Important Questions for exam preparation. Students can also go through RBSE Class 11 Biology Notes to understand and remember the concepts easily.

RBSE Class 11 Biology Solutions Chapter 20 Locomotion and Movement

RBSE Class 11 Biology Locomotion and Movement Textbook Questions and Answers

Question 1. 
Draw the diagram of a sarcomere of skeletal muscle showing different regions.
Answer:
RBSE Solutions for Class 11 Biology Chapter 20 Locomotion and Movement 1

Question 2. 
Define sliding filament theory of muscle contraction.
Answer:
The sliding of thin filaments from both the sides over the thick filaments of sacromere, resulting in shortening of sarcomere and contraction of muscle fibre is called sliding filament theory.

RBSE Solutions for Class 11 Biology Chapter 20 Locomotion and Movement

Question 3. 
Describe the important steps in muscle contraction.
Answer:

The muscles that appear reddish in colour are called red muscles. It is because of presence of myoglobin, a red coloured oxygen storing pigment in high percentage in muscles, These muscle fibres also have large number of mitochondria which can utilise the large amount of oxygen stored in them for ATP production. Therefore, these muscles are also called aerobic muscles. Lactic acid accumulation does not occur and they do not fatigue because of presence of oxygen.

Those muscles that are pale or whitish in appearance are called white muscles or fibres. These muscles have lesser percentage/quantity of myoglobin and mitochondria also. But the sarcoplasmic reticulum is high. They depends on anaerobic process for energy and thus can be called anaerobic muscles. Lactic acid accumulation takes place and results in fatigue, e.g., muscle of eye ball.

Question 4. 
Write true or false. If false change the statement so that it is true.
(a) Actin is present in thin filament.
(b) H - zone of striated muscle fibre represents both thick and thin filaments.
(c) Human skeleton has 206 bones.
(d) There are 11 pairs of ribs in man.
(e) Sternum is present on the ventral side of the body.
Answer:
(a) True 
(b) False ; H - zone represents the central portion of sarcomere and it has myosin.
(c) True 
(d) False ; There are 12 pairs of ribs in human body.
(e) True.

Question 5. 
Write the difference between:
(a) Actin and Myosin
(b) Red and White muscles.
(c) Pectoral and Pelvic girdle.
Answer:
Comparision between
(a) 

Actin Filaments

Myosin Filaments

1. Actin filaments are also called thin filaments and are few in number.

1. Myosin filaments are also called thick filaments and are more in number.

2. These are found in T - bands.

2. These are found in ‘A’ - bands only.

3. About 300 actin filaments are present in each myofibril.

3. About 1500 myosin filaments are present in each myofibril.

4. One end of these filaments are attached to ‘Z’ line and other end is free and overlap the myosin filaments.

4. Both the ends are free.

5. The surface is almost smooth.

5. The surface has out growth except at ‘M’.

6. Actin filaments are made up of globular protein and tropomyosin.

6. Myosin filaments are club shaped and filamentous.

7. They slide over myosin filaments.

7. During contraction they remain at their position i. e., they do not move.

8. Cross bridges are absent.

8. Cross bridges are present.


(b) 

Red Muscle

White Muscle

1. Muscles that are rich in myoglobin and mitochon - dria are known as red muscles.

1. Muscles that are not rich in myoglobin and mitochondria.

2. They appear reddish in colour.

2. They appear whitish/pale in colour.

3. They utilize more oxygen to produce more ATP production.

3. They utilise less oxygen and produce less ATP.

4. They are also called aerobic muscles.

4. They are also called anaerobic muscles.

5. They do not get fatigued.

5. They easily get fatigued because of lactic acid accumulation.


(c) 

Pectoal Girdle

Pelvic Girdle

1. It is present in shoulder region.

1. It is present in pelvic region.

2. It has two separate parts. They are isolated.

2. It has two parts that are attached at pubic symphysis.

3. Each portion has scapula and clavicle.

3. Each portion has ilium, ischium and pubis.

4. The scapula has glenoid cavity and head of humerus fits in.

4. It has accetabulum cavity. The head or femur fits in.

5. Clavicle is also called collar bone.

5. Both portion fuse to make pubic symphysis.


Question 6. 
Match column I with column II

Column I

Column II

(a) Smooth muscle

(i) Myoglobin

(b) Tropomyosin

(ii) Thin filament

(c) Red muscle

(iii) Sutures

(d) Skull

(iv) Involuntary


Answer:

Column I

Column II

(a) Smooth muscle

(iv) Involuntary

(b) Tropomyosin

(ii) Thin filament

(c) Red muscle

(i) Myoglobin

(d) Skull

(iii) Sutures


RBSE Solutions for Class 11 Biology Chapter 20 Locomotion and Movement

Question 7. 
What are the different types of movements exhibited by the cells of human body?
Answer:
There are 3 types of movements exhibited by the cells or human body:
(a) Amoeboid movement    
(b) Cilliary movement
(c) Muscular movement.

Question 8. 
How do you distinguish between a skeletal muscle and a cardiac muscle?
Answer:

Skeletal muscle

Cardiac muscle

1.  These muscles are attached to the bones hence, called skeletal muscles.

1. These muscles are present in the heart walls hence, called cardiac muscle.

2. These muscles are controlled by will and are known as voluntary muscle.

2. These muscles are not controlled by will. They are involuntary.

3. The muscle fibre is covered with membrane called sarcolemma.

3. The muscle fibres are branched and form a net. There is no clear sarcolemma.

4. Each muscle fibre has several nucleus.

4. Each fibre usually has one nucleus.

5. These muscles has striated appearence due to I - bands (light) and A bands (dark). Therefore, also called striated muscles.

5. The muscles have light bands and dark bands. There are intercalated discs present as intervals.

6. These muscles get tired/ fatigue due to working. Hence, these need resting.

6. These muscles keep working throughout the life.


Question 9. 
Name the type of joint between the following: 
(a) Atlas / axis    
(b) Carpal / metacarpal of thumb.
(c) Between phalanges.
(d) Femur/acetabulum.
(e) Between cranial bones.
(f) Between pubic bones in the pelvic girdle.
Answer:
(a) Pivot joint    
(b) Saddle joint
(c) Saddle joint    
(d) Ball and socket joint
(e) Immovable joints 
(f) Imperfect joint.

Question 10. 
Fill in the blank spaces:
(a) All mammals (except a few) have .................. cervical vertebra.
(b) The number of phalanges in each limb of human is .................. .
(c) Thin filament of myofibril contains 2 ‘F’ actins and two other proteins namely .................. and .................. .
(d) In a muscle fibre Ca++ is stored in .................. .    
(e) .................. and .................. pairs of ribs are called floating ribs. 
(f) The human cranium is made of .................. bones.
Answer:
(a) Seven 
(b) fourteen 
(c) tropin, tropomyosin 
(d) sarcoplasmic reticulum 
(e) 11th, 12th 
(f) eight.

Bhagya
Last Updated on July 6, 2022, 10:32 a.m.
Published July 5, 2022