Locomotion and Movement

NEET Biology · 98 questions · Page 4 of 10 · Click an option or "Show Solution" to reveal answer

Q31

Characteristics of smooth muscle fibres are

A spindle-shaped, unbranched, unstriated, uninucleate and involuntary

B spindle shaped, unbranched, unstriped, multinucleate and involuntary

C cylindrical, unbranched, unstriped, multinucleate and involuntary

D cylindrical, unbranched, striated, multinucleate and voluntary

Correct Answer

Option A

Solution

(a) Smooth muscle fibres are spindle-shaped, unbranched, unstriated, uninucleate and involuntary.

Q32

Characteristics of smooth muscle fibres are

A spindle-shaped, unbranched, unstriated, uninucleate and involuntary

B spindle shaped, unbranched, unstriped, multinucleate and involuntary

C cylindrical, unbranched, unstriped, multinucleate and involuntary

D cylindrical, unbranched, striated, multinucleate and voluntary

Correct Answer

Option A

Solution

(a) Characteristics of smooth muscle fibres. cells range from 5 to $10 \mu m$ in diameter and 30 to $200 \mu m$ in length spindle-shaped single, centrally located nucleus smooth muscle tissue occuring within almost every organ, forming sheets, bundles or sheaths around other tissues.

Smooth muscle differs from both skeletal and cardiac muscle tissues in structure and function.

Sarcomeres or myofibrils are not present - therefore not striated, ie. smooth.

Q33

Which statement is correct for muscle contraction?

A Length of

H

-line decreases

B Length of A-band remains constant

C Length of I-band increases

D Length of two Z-lines increase

Correct Answer

Option A

Solution

(a,b) When $Ca^{+}$ ions combine with troponin contraction of muscles initiates.

During contraction the $Z$ lines come closer together and the sarcomere becomes shorter.

The length of A band remains constant.

I bands shortens and H-band narrows.

Q34

Which of the following is the contractile protein of a muscle?

A Myosin

B Tropomyosin

C Actin

D Tubulin

Correct Answer

Option A

Solution

(a) Actin and tropomyosin are part of thin filaments of skeletal muscle.

Tubulin is presents in microtubules.

Myosin is muscle protein.

Q35

Which one of the following pairs of chemical substances is correctly categorized?

A Calcitonin and thymosin - Thyroid hormones

B Pepsin and prolactin - Two digestive enzymes secreted in stomach

C Troponin and myosin - Complex proteins in striated muscles

D Secretin and rhodopsin - Polypeptide hormones

Correct Answer

Option C

Solution

Both actin and myosin are complex proteins in striated muscles.

Thymosin is a hormone secreted by the thymus that stimulates development of T cells.

Prolactin is a hormone released by the pituitary gland that stimulates breast development and milk production in women.

Rhodopsin, also known as visual purple, is not a hormone.

It is a biological pigment in photoreceptor cells of the retina that is responsible for the first events in the perception of light.

Q36

Select the correct option:

8^{\text{th }}, 9^{\text{th }}

and

10^{\text{th }}

pairs of ribs articulate directly with the sternum.

11^{\text{th }}

and

12^{\text{th }}

pairs of ribs are connected to the stemum with the help of hyaline cartilage.

C Each rib is a flat thin bone and all the ribs are connected dorsally to the thoracic vertebrae and ventrally to the sternum.

D There are seven pairs of vertebrosternal, three pairs of vertebrochondral and two pairs of vertebral ribs.

Correct Answer

Option D

Solution

(d) There are 12 pairs of ribs in human body.

First seven pairs are attached to the sternum ventrally with the help of hyaline carlilage, also called as true ribs.

These are called vertebrosternal ribs.

The next three pairs (8th, 9 th and 10th) do not articulate directly with the sternum, also called vertebrochondral (false) ribs .

The last two pairs (11th and 12th) are the free floating ribs because they are not connected ventrally.

Q37

Match the following joints with the bones involved: Column-I Column-II

A -(iv),

B -(ii),

C -(iii),

D -(i)

Correct Answer

Option B

Solution

(b) Gliding joint is present between the carpals.

Hinge joint is present between humerus and ulna.

Pivot joint is present between atlas and axis.

Saddle joint is present between carpal and metacarpal of thumb.

Q38

Match the following columns and select the correct option. Column-I Column-II

A (i) (iii) (ii) (iv)

B (iii) (ii) (iv) (i)

C (iv) (iii) (i) (ii)

D (ii) (iv) (i) (iii)

Correct Answer

Option C

Solution

Acromion is a flat expanded process of spine of scapula.

The lateral end of clavicle articulates with acromion process.

Scapula is a flat triangular bone in the dorsal part of the thorax between $2nd$ and the $7th$ rib.

Glenoid cavity of scapula articulates with head of the humerus to form the shoulder joint.

The acromion of the scapula is a large bony projection on the superior end of the scapula.

It is an important landmark of the skeletal system and a muscle attachment point essential to the function of the shoulder joint.

The acromion also forms the acromian clavicular (AC) joint with the clavicle.

Q39

What is sarcomere?

A Part between two

\mathrm{H}

-lines

B Part between two A-lines

C Part between two I-bands

D Part between two Z-lines

Correct Answer

Option D

Solution

(d) Darks bands on the myofibril form A-band.

Middle part of A-band contains light zones-Hensen line (H-lines).

Light band on myofibril is called I-band.

Middle part of I-band contains Z-lines.

Sarcomere is part between two Z-lines.

Q40

Which is part of pectoral girdle?

A Glenoid cavity

B Sternum

C Ilium

D Acetabulum

Correct Answer

Option A

Solution

(a) Glenoid cavity is a shallow concavity on the lateral side of the pectoral girdle (scapula).

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