NCERT Class 11-Biology: Chapter –20 Locomotion and Movement Part 2

Get top class preparation for CBSE/Class-8 Science right from your home: fully solved questions with step-by-step explanation- practice your way to success.

Download PDF of This Page (Size: 136K)

Question 12:

Which one of the following statements is true?

a. Head of humerus bone articulates with acetabulum of pectoral girdle.

b. Head of humerus bone articulates with glenoid cavity of pectoral girdle.

c. Head of humerus bone articulates with a cavity called acetabulum of pelvic girdle.

d. Head of humerus bone articulates with a glenoid cavity of pelvic girdle.

Answer: (b)

Question 13:

Muscles with characteristic striations and involuntary are

a. Muscles in the wall of alimentary canal

b. Muscles of the heart

c. Muscles assisting locomotion

d. Muscles of the eyelids

Answer: (b)

Question 14:

Match the followings and mark the correct option

Match the Followings and Mark
Match the followings and mark

Column I

Column I

A.

Sternum

i.

Synovial fluid

B.

Glenoid Cavity

ii.

Vertebrae

C.

Freely movable joint

iii.

Pectoral girdle

D.

Cartilagenous joint

iv.

Flat bones

Options:

a. A-ii, B-i, C-iii, D-iv

b. A-iv, B-iii, C-i, D-ii

c. A-ii, B-i, C-iv, D-iii

d. A-iv, B-i, C-ii, D-iv

Answer: (b)

Very Short Answer Type Questions

Question 1:

Name the cells/tissues in human body which

a. exhibit ameboid movement

b. exhibit ciliary movement

Answer:

(a) Macrophages

(b) Ciliated epithelium

Question 2:

Locomotion requires a perfect coordinated activity of muscular, _____, _______ systems

Answer:

Skeletal and Neural

Question 3:

Sarcolemma, sarcoplasm and sarcoplasmic reticulum refer to a particular type of cell in our body. Which is this cell and to what parts of that cell do these names refer to?

Answer:

These names refer to the muscle cells or muscle fibers. They are lined by a plasma membrane, which is known as sarcolemma, which encloses the sarcoplasm. The sarcoplasmic reticulum refers to the endoplasmic reticulum of the muscle cells, which acts as a storehouse for calcium ions.

Question 4:

Label the different components of actin filament in the diagram given below.

Chapter 20- Question 4 - Images of the Different Components of Actin Filament

Different Components of Actin Filament

Chapter 20- Question 4 - Images of the Different Components of Actin Filament

Answer:

  • Troponin: It acts as a mask for active binding sites for myosin in the actin filament when it is in the resting state.

  • Tropomyosin: It is a protein which is involved in the contraction of the skeletal muscles, and when required, it prevents myosin interaction.

Question 5:

The three tiny bones present in middle ear are called ear ossicles. Write them in correct sequence begining from ear drum.

Answer:

The correct sequence of the three bones present in the middle ear are:

  • Malleus: It is the hammer-shaped component of the middle ear, which helps in transmitting the sound vibrations from the eardrum to the incus.

  • Incus: It is an anvil-shaped component of the middle ear which receives vibrations from the malleus and helps in transmitting these vibrations to the stapes medially.

  • Stapes: It is a stirrup-shaped component of the middle ear, which helps in the conduction of sound vibrations to the inner ear.

Question 6:

What is the difference between the matrix of bones and cartilage?

Answer:

The bone matrix is very hard due to presence of calcium, while the cartilage matrix is pliable due to chondroitin salts.

Question 7:

Which tissue is afflicted by Myasthenia gravis? What is the underlying cause?

Answer:

Skeletal muscle is affected by Myasthenia gravis. It happens because of immune disorder.

Developed by: