Biology · General Awareness

Muscle Biology

798 Questions

Muscle biology covers the structures, functions, and contraction mechanisms of skeletal, cardiac, and smooth muscles. Test questions target filaments, stimuli, and specific muscle roles. A clear understanding helps secure marks in biology sections.

Skeletal muscle controlCardiac muscle propertiesMuscle contraction mechanismActin and myosin filamentsMuscle functions

Muscle Biology Questions

Multiple choice zoology movement and locomotion in man structure of skeletal muscle muscles and their structure skeletal muscles

Anisotropic band is made of

  1. Myosin filaments

  2. Actin filaments

  3. Elastin filaments

  4. Both A and B
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
  • Skeletal muscle fiber is made up of two types of filaments. They are thick filament (myosin) and thin filament (actin). The ‘A’ and ‘I’ bands are arranged alternately throughout the length of the myofibrils.
  • The A band in skeletal muscle is also called as anisotropic band.
  • The anisotropic band is made of both actin filaments and myosin filaments.
  • So, the correct answer is 'Both A and B'.
Multiple choice zoology movement and locomotion in man structure of skeletal muscle muscles and their structure skeletal muscles

Skeletal muscles are controlled by

  1. Somatic nerves

  2. Autonomic nerves

  3. Parasympathetic nerves

  4. Sympathetic nerves
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Somatic nerves are part of the peripheral nervous system and are responsible for the voluntary control of skeletal muscles. Autonomic, sympathetic, and parasympathetic nerves control involuntary functions like heart rate and digestion.

Multiple choice zoology movement and locomotion in man structure of skeletal muscle muscles and their structure skeletal muscles

H-zone in skeletal muscle fibre is due to

  1. Extension of myosin filaments in central portion of A-band.

  2. Absence of myofibrils in the central portion of A-band.

  3. Central gap between filaments in A-band.

  4. Central gap between actin filaments extending through myosin filaments in A-band.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
  • Myofibril is made up of two types of filaments. They are thin filament(actin) and thick filament(myosin).
  • The light bands contain actin and are called I-band or Isotropic band, whereas the dark band called ‘A’ or Anisotropic band contains myosin. The ‘A’ and ‘I’ bands are arranged alternately throughout the length of the myofibrils.
  •  In a resting state, the edges of thin filaments on either side of the thick filaments partially overlap the free ends of the thick filaments leaving the central part of the thick filaments. This central part of thick filament, not overlapped by thin filaments is called the ‘H’ zone.
  • Hence H-zone in skeletal muscle fibre is due to Central gap between actin filaments extending through myosin filaments in A-band.
  • So, the correct answer is 'Central gap between actin filaments extending through myosin filaments in A-band'.
Multiple choice zoology movement and locomotion in man structure of skeletal muscle muscles and their structure skeletal muscles

Identify the correct statements.

1. A-bands are dark and contain myosin.
2. I-bands are light and contain actin.
3. During the action, A band contracts.
4. The part between two Z-lines is sarcomere.
5. The central part of thin filament, not overlapped by thick filament is the H-zone.

  1. 1, 2 and 3 are correct

  2. 1, 3 and 5 are correct

  3. 1, 2 and 4 are correct

  4. 1 and 2 are correct

  5. 1, 2, 3 and 5 are correct
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • The ‘A’ and ‘I’ bands are arranged alternately throughout the length of the myofibrils. The light bands contain actin(thin filament) and are called I-band or Isotropic band, whereas the dark band called ‘A’ or Anisotropic band contains myosin(thick filament). In the centre of each ‘I’ band is an elastic fibre called ‘Z’ line which bisects it. The thin filaments are firmly attached to the ‘Z’ line. The portion of the myofibril between two successive ‘Z’ lines is considered as the functional unit of contraction and is called a sarcomere 
  • Utilizing the energy from ATP hydrolysis, the myosin head now binds to the exposed active sites on actin to form a cross bridge. 
  • This pulls the attached actin filaments towards the centre of ‘A’ band.
  • The ‘Z’ line attached to these actins are also pulled inwards thereby causing a shortening of the sarcomere, i.e., contraction. Hence the ‘I’ bands get reduced, whereas the ‘A’ bands retain the length.
  •  The central part of thick filament, not overlapped by thick filament is the H-zone.
  • So, the correct answer is '1,2 and 4
Multiple choice zoology movement and locomotion in man structure of skeletal muscle muscles and their structure skeletal muscles

Myofibrils show dark and light bands in

  1. Cardiac muscles

  2. Unstriped muscles

  3. Striped muscles

  4. Both A and C
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
  • The striated appearance of skeletal and cardiac muscle tissue is a result of repeating bands of the proteins actin and myosin that are present along the length of the myofibril.
  • The light bands contain actin and are called I-band or Isotropic band, whereas the dark band called ‘A’ or Anisotropic band contains myosin. Hence called striped muscles due to the presence of striations.
  • Hence Myofibrils show dark and light bands in Cardiac muscles and striped muscles.
  • So, the correct answer is 'Both A and C'.
Multiple choice zoology movement and locomotion in man structure of skeletal muscle muscles and their structure skeletal muscles

Cross bridges of sarcomere in skeletal muscle are made up of 

  1. Actin

  2. Myosin

  3. Troponin

  4. Tropomyosin
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • Active sites for myosin (Thick filament) are present on actin which are masked by troponin in resting state. when  Ca++ level increases it leads to the binding of calcium with a subunit of troponin on actin(thin) filaments and thereby remove the masking of active sites for myosin.
  • Utilizing the energy from ATP hydrolysis, the myosin head now binds to the exposed active sites on actin to form a cross bridge. thus myosin forms cross bridges.
  • This pulls the attached actin filaments towards the centre of ‘A’ band.
  •  The ‘Z’ line attached to these actins are also pulled inwards thereby causing a shortening of the sarcomere, i.e., contraction.
  • Hence cross bridges of sarcomere in skeletal muscle are made up of myosin.
  • So, the correct answer is 'Myosin'.
Multiple choice zoology movement and locomotion in man structure of skeletal muscle muscles and their structure skeletal muscles

State whether the following statements are true or false.
Intercalated discs make up striations in the skeletal muscle.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Intercalated discs support synchronized contraction of cardiac tissues. They occur at the Z line of the sarcomere and can be visualized easily when observing a longitudinal section of the tissue. Three types of cell junction make up an intercalated disc.

So, the option is 'False'.

Multiple choice zoology movement and locomotion in man structure of skeletal muscle muscles and their structure skeletal muscles

Which muscles having functionally multinucleated conditions?

  1. Cardiac muscle

  2. Smooth muscle

  3. Voluntary muscle

  4. All of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

There are cardiac, skeletal and smooth muscle cells of which only skeletal or voluntary muscle cells are multinucleated. Such cells are syncytial. Skeletal muscle cells arise in the embryo as uninucleated entities. Later the cells fuse to give rise to the multinucleated muscle fibre.

So the correct answer should be option C "voluntary muscles".

Multiple choice biology animal tissue muscular tissues muscle tissue muscle tissues

The muscle fatigue occurs due to accumulation of

  1. ${ CO } _{ 2 }$

  2. Lactic acid

  3. Creatine phosphate

  4. Myosin ATPase
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Aerobic respiration gives more energy but is a slow process. Anaerobic respiration like lactic acid fermentation is a fast process but releases less energy. In the case of rapid muscular contraction, the muscles perform lactic acid fermentation to provide for rapid energy intake. This process releases lactic acid which causes pain and muscle fatigue. So, the correct answer is option B.

Multiple choice biology animal tissue muscular tissues muscle tissue muscle tissues

Movements in body are brought about by ____________

  1. Muscular tissue

  2. Epithelial tissues

  3. Bones

  4. Tendons and ligaments
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Epithelial tissues are meant for covering and protecting the body, organs and cavities. They are not involved in body movements.
Bones form the framework of the body. They are hard and rigid. To carry out body movement property of contraction and relaxation is necessary. But bones can not contract.
Tendon is a tough fibrous connective tissue, which connects muscle to bone. Tendon does not have the property of contraction and relaxation. The ligament is a fibrous connective tissue, which connects bone to another bone. It is flexible but is not present throughout the body to carry out body movement.
Muscular tissues possess the property of contraction and relaxation. They are attached to bones. With the help of bones, muscular tissue carries out body movement. Therefore, option A is correct. 

Multiple choice biology animal tissue muscular tissues muscle tissue muscle tissues

Contraction and relaxation are unique features of_______________

  1. Epithelial tissue

  2. Connective tissue

  3. Muscle tissue

  4. Nervous tissue
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Epithelial tissue is meant for covering and protecting the body, organs and cavities. They do not possess the property of contraction and relaxation. 
Connective tissue connects, supports and separates the organs in the body. These are present in different forms as fluid, jelly-like rigid, hard forms. 
Nervous tissue is meant for rapid transmission of the signals from one place to another. These tissues do not contract or relax.

Muscle cells are elongated and possess contractile proteins as actin, myosin. These proteins carry out contraction and relaxation of muscles and cause the body movement. Therefore, option C is correct. 

Multiple choice biology animal tissue muscular tissues muscle tissue muscle tissues

The cytoplasm of a muscle cell is known as

  1. Neuroplasm

  2. Sarcolemma

  3. Axoplasm

  4. Sarcoplasm
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Sarcoplasm is the cytoplasm of muscle cells or myocytes. Large amounts of glycosomes and significant amounts of myoglobin are usually found in the sarcoplasm.

So, the correct answer is 'Sarcoplasm'. 

Multiple choice biology animal tissue muscular tissues muscle tissue muscle tissues

Which of the following tissue provide movement and locomotion to the body?

  1. Connective tissue

  2. Locomotory tissue

  3. Muscular tissue

  4. Adipose tissue
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Muscle tissue helps in locomotion and provides a structural framework to  the body. These have contractile proteins for contraction and relaxation. It controls voluntary and involuntary actions. It is separated into three distinct categories, smooth muscle, skeletal muscle and cardiac muscle. So, the correct answer is option C.

Multiple choice biology animal tissue muscular tissues muscle tissue muscle tissues

.......... gives rise to the ability of muscles to contract.

  1. Nervous tissue

  2. Muscle tissue

  3. Connective tissue

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Muscular tissue provides a structural framework to the body along with connective tissue. It has immense potential to contract as they have major contractile proteins like actin and myosin. The muscle contraction requires ATP which hydrolyses to ADP and inorganic phosphate to allow the overlap of the contractile proteins during muscle contraction. The calcium ions released by the sarcoplasmic reticulum acts as a cofactor to activate the contractile proteins.

So, the correct answer is option B.

Multiple choice biology animal tissue muscular tissues muscle tissue muscle tissues

Which of the following proteins has an impact on the regulation of internal movements?

  1. Actin

  2. Myosin

  3. Tropomyosin

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Actin is the thin filament which is present in the muscles. Myosin is the thicker filaments in the muscles. The tropomyosin is the regulatory protein which is present in the grooves of the actin filament. This is the regulatory protein which helps in the contraction and relaxation of the myosin bridge. These proteins are the structural units of the muscle fibres and help in the contraction and relaxation of muscles to allow internal movement of the involuntary muscles. 

Thus, the correct answer is option D.