Class 11 Biology Important Chapter 17 Locomotion and Movement

Class 11 Biology Important Chapter 17 Locomotion and Movement Solutions English Medium As Per AHSEC New Syllabus to each chapter is provided in the list so that you can easily browse through different chapters ASSEB Class 11 Biology Important Solutions and select need one. AHSEC Class 11 Biology Additional Notes English Medium Download PDF. HS 1st Year Biology Important Solutions in English.

Class 11 Biology Important Chapter 17 Locomotion and Movement

Also, you can read the NCERT book online in these sections Solutions by Expert Teachers as per Central Board of Secondary Education (CBSE) Book guidelines. ASSEB Class 11 Biology Additional Question Answer are part of All Subject Solutions. Here we have given HS 1st Year Biology Important Notes in English for All Chapters, You can practice these here.

Locomotion and Movement

Chapter: 17

IMPORTANT QUESTION AND ANSWER

Very Short and Short Answer Type Question:

1. Define myofibrils.

Ans. Each skeletal muscle fibre has large number of parallel arranged filaments called myofilaments or myofibrils.

2. Why are red muscles known as aerobic muscles?

Ans. Because of myoglobin mitochondrion in them. and  mitochondria in them. 

3. What is the reason for muscle fatigue?

Ans. It occurs due to accumulation of lactic acid as a result of anaerobic breakdown of glycogen in muscle.

4. What do you mean by Dicondylic skull in humans?

Ans. Dicondylic skull The skull is connected to vertebral column with two occipital condyles.

5. What is arthritis?

Ans. Inflammation of the joints.

6. What causes fatigue of muscle fibre?

Ans. Accumulation of lactic acid in muscle.

7. Name the protein which constitute A and I bands of muscle fibre.

Ans: Myosin and Actin.

8. Name the two functional types of smooth muscles.

Ans. (i) Single unit smooth muscles.

(ii) Multi unit smooth muscles.

9. Name the tissue which connects muscles to a bone.

Ans. Tendon.

10. Name the functional contractile unit of muscle.

Ans. Sarcomere-a part of myofibril.

11. Explain the sliding filament theory of muscle contraction.

Ans: The sliding filament theory explains how muscles contract by the sliding of actin (thin) filaments over myosin (thick) filaments. When stimulated, calcium ions are released, which bind to troponin, shifting tropomyosin and exposing binding sites on actin. The myosin heads then bind to these sites, forming cross-bridges and pulling actin filaments inward using energy from ATP. This shortens the sarcomere, resulting in muscle contraction. The process continues in a cyclic manner until relaxation is triggered.

12. What are true ribs?

Ans. The first seven pairs are called true ribs because their anterior ends are attached directly to the sternum by hyaline cartilage called coastal cartilages.

13. Describe any two common features in a hinge joint and a ball and socket joint.

Ans. (i) Allow the movement of articu-lating bones such that they can move upon each other extensively.

(ii) Synovial cavity (space between bones) remains filled with viscous and slippery synovial fluid.

14. What are the major functions of the skeletal system?

Ans: The skeletal system plays a vital role in maintaining the structure and functionality of the human body. 

Its major functions include:

(i) Support: It provides a rigid framework that supports the body and maintains its shape.

(ii) Protection: The skeleton protects delicate internal organs. For example, the skull protects the brain, and the rib cage shields the heart and lungs.

(iii) Movement: Bones act as levers and joints as fulcrums. Muscles attached to bones enable movement of body parts.

(iv) Mineral Storage: Bones serve as a reservoir for essential minerals such as calcium and phosphorus, releasing them into the bloodstream when needed.

(v) Blood Cell Production: The bone marrow, especially in long bones, is the site for the production of red blood cells, white blood cells, and platelets.

(vi) Detoxification: Bones can absorb heavy metals and other toxic substances from the blood, thereby helping in detoxifying the body.

15. What is contractibility of muscle fibres ?

Ans. The contractibility is the property of shortening (contraction) of muscle fibres and their return to relaxed state (relaxation) based on relative position of different intracellular filaments.