LOCOMOTION AND MOVEMENT

1. Name the portion of the myofibril between two successive Z-lines. (Score 1)
(a) H-zone

(b) Sarcomere
(c) I-band

(d) M-line

Answer:

(b) Sarcomere

2. Observe the figures given below:

a) Identify figures A and B.
b) Name the subunits of A and B. (Score 2)

Answer:

(a) A= Actin, B= Myosin.

(b) A= G- actin, B= Meromyosin (HMM + LMM)

3. Identify the following figure. Label A, B & C. (Score 2)

Answer:

Cross bridge formation during muscle contraction.
A= Actin filament. B= Myosin filament. C= Cross bridge.

4. How does the increased level of calcium ion in the sarcoplasm help in muscle contraction? (Score 2)

Answer:

Ca ion binds with a subunit of troponin on actin filaments and unmask the active sites for myosin.

Using energy from ATP hydrolysis, myosin head binds to active sites on the actin to form cross bridge.

5. Compete the following chart showing the structure of myosin filament and its protein based on the hints given in the brackets. (Score 2)

(Light meromyosin, Actin, Tropomyosin, Meromyosin)

Answer:

(A) Meromyosin

(B) Light meromyosin

6. (a) Observe the following figure and label A, B & C.

(b) First 7 ribs are ventrally connected to sternum with the help of …………….

Answer:

(a) A= True ribs, B= False ribs, C= Floating ribs.

(b) Hyaline cartilage.

7. Mention three main types of joints with one example for each. (Score 3)

Answer:

a. Fibrous (immovable) joints: E.g. sutures b/w skull bones.

b. Cartilaginous joints (Slightly movable joints): E.g. Joints between the adjacent vertebrae.

c. Synovial (movable) joints: E.g. Shoulder joint.

8. Identify the disorders based on the symptoms given below. (Score 2)

a. Inflammation of joints.

b. Decreased bone mass and increased chance of fracture.

c. Inflammation of joints due to the accumulation of uric acid crystals.

d. Rapid spasms in muscles due to low Ca⁺⁺ in body fluids.

Answer:

(a) Arthritis

(b) Osteoporosis

(d) Tetany

Focus Area 2021 | Questions and Answers | Plus One Zoology | Locomotion and Movement