Question 1

Select the correct statement regarding red and white muscle fibres.

Accepted Answer

White muscle fibres are thicker in comparison to the red muscle fibres. They have a faster rate of contraction because they show spontaneous and quick movements.

Question 2

Aerobic muscles called …A… and anaerobic muscles are called …B… . Here A and B refers to :

Accepted Answer

Muscle contains a red coloured oxygen storing pigment called myoglobin. Myoglobin content is high in some of the muscles which gives them a reddish appearance. Such muscles are called the red fibres. These muscles, also contains plenty of mitochondria, which can utilise the large amount of oxygen stored in them for ATP production. These muscles therefore, can also be called aerobic muscles.

Question 3

Functional unit of skeletal muscle is called :

Accepted Answer

Sarcomere is the functional unit of myofibril. It is the part of myofibril between two successive Z-lines, which consists of two Iband halves, and an A-band between them. The region contains a bundle of two types of protein filaments, actin and myosin. Upon contraction, the actin filaments slide towards the centre of the myosin filaments,andoverall sarcomere length get smaller.

Question 4

Fascicles are held together by the structure :

Accepted Answer

Each organized skeletal muscle in our body is made of a number of muscle bundles or fascicles held together by a common collagenous connective tissue layer called fascia. Each muscle bundle contains a number of muscle fibres.

Question 5

Intervertebral disc consists of a shock absorber connective tissue known as :

Accepted Answer

Fibro cartilage possess thick dense bundles of collagen fibres in matrix. White fibrocartilage is the strongest cartilage. It occurs in joints between vertebrae functioning as shock absorber and also in pubic symphysis.

Question 6

Skeletal muscles are closely associated with the …A… components of the body. They have …B… appearance under the microscope and hence are called …C… musclesChoose the correct options to fill A, B and C, so as to complete the given NCERT statement.

Accepted Answer

A-Skeletal, B-Stripped, C-StriatedSkeletal muscles are closely associated with the skeletal components of the body. They have stripped appearance under the microscope and hence are called striated muscles.

Question 7

In a vertebrate, which germ layer forms the skeleton muscles?

Accepted Answer

Mesoderm, the middle embryonic germ layer, lying between the ectoderm and the endoderm, from which connective tissue, muscle, bones etc.

Question 8

In certain parts of India muscular distrophy is commonly found among the poor people because they eat cheap pulses of

Accepted Answer

Lathyrus sativus also known as Kesari dal is mainly consumed by poor people. It causes paralysis because of the action of neurotoxin OAA present in it.

Question 9

According to the functions the skeletal muscles is/are :

Accepted Answer

Skeletal muscles, or "voluntary muscles", are  striated muscle tissue which  primarily joins , bone with tendons. Skeletal muscle enables movement of bones, and maintains posture.Prime mover: a muscle that has the major responsibility for producing a specific movement. Antagonist: muscles that oppose, or reverse, a particular movement. Synergist: helps prime movers by adding a little extra force to the same movement or by reducing undesirable or unnecessary movements.

Question 10

Which of the following is not the feature of red muscle fibres?

Accepted Answer

Red muscle fibres are one of the two main types of skeletal muscle, which contains abundant mitochondria and myoglobin. Red muscle fibres contract and fatigue more slowly than white fibres and generate ATP by aerobic catabolism of glucose and fats, utilising myoglobin-bound O2​. Sarcoplasmic reticulum is a system of membrane-bound tubules that surrounds muscle fibrils, releasing calcium ions during contraction and absorbing them during relaxation.

Question 11

Which character is not associated with White muscle fibres?

Accepted Answer

Muscle contains a red coloured oxygen storing pigment called myoglobin. Myoglobin content is high in some of the muscles which gives a reddish appearance. Such muscles are called the Red fibres. These muscles also contain plenty of mitochondria which can utilise the large amount of oxygen stored in them for ATP production. These muscles, therefore, can also be called aerobic muscles. On the other hand, some of the muscles possess very less quantity of myoglobin and therefore, appear pale or whitish. These are the White fibres. Number of mitochondria are also few in them, but the amount of sarcoplasmic reticulum is high.

Question 12

The term isotropic refers to:

Accepted Answer

The light bands of myofibrils, containing actin proteins are called isotropic because in polarized light, these bands are not bi-refractive and show isotropic behaviour.

Question 13

Which of the following is the correct name of the given tissue?

Accepted Answer

Skeletal muscle

Question 14

Which of the following option clearly identifies striated muscles?

Accepted Answer

Cylindrical, striped and unbranched

Question 15

Locomotory actions within human body are carried out using

Accepted Answer

Locomotory actions within human body are carried out using striated muscles or skeletal muscles. These muscles are closely associated with the skeletal components of the body and are primarily involved in locomotory actions and changes of body postures.

Question 16

The muscle bundles, fascicles are held together by the collagenous connective tissue called

Accepted Answer

The muscle bundles, fascicles are held together by the collagenous connective tissue called fascia.

Question 17

Choose the incorrect pair.

Accepted Answer

The pair in option (c) is incorrect and can be corrected asDark bands are called A-bands or Anisotropic bands whereas light bands are Isotropic or I-bands.Rest of the pairs are correctly matched.

Question 18

In the centre of each I-band, there is an elastic fibre called

Accepted Answer

In the centre of each I-band, there is an elastic fibre called Z-line, which bisects it. The thin filaments are firmly attached to the Z-line.

Question 19

Cross arms of the myosin monomer consist of

Accepted Answer

The cross arms of myosin monomer consist of a head and short arm which projects outwards at regular distance and angle from each other, from the surface of polymerised myosin filament. The globular head is an active ATPase enzyme and has binding sites for ATP and active sites for actin.

Question 20

Identify A,B and C in the given diagram.

Accepted Answer

The given diagram is of an actin filament in which A is troponin B is tropomyosin and C is F-actin.

Filters

Filters

class

subject

topic

concept

difficulty

Solutions for Red and White Skeletal Muscle Fibres Important Questions

Found the solution, but did not understand the concept?

Ask my first question