Tag: muscle contraction

Questions Related to muscle contraction

EDTA injected into muscles combines with $Ca^{2+}$ and

biology skeleton and movements locomotion in animals bones and movements muscle contraction

  1. Stops contraction

  2. Causes contraction

  3. Slows down contraction

  4. None of the above

Show answer
Correct Option: C
Explanation:
  • Active sites for myosin 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. 
  • 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.
  • When EDTA  injected into muscles combines with Ca ++ and prevents the binding of calcium with troponin and slows down contraction.
  • So, the correct answer is 'Slows down contraction'. 

The cartilage which is present in nasal septum is aIso found in :-

biology skeleton - movement and locomotion locomotion in animals bones and movements muscle contraction

  1. Pubic symphysis

  2. Tip of nose

  3. Ear pinna

  4. Sternal part of ribs

Show answer
Correct Option: A

In addition to muscular system, vertebrates have evolved______ system for faster locomotion.

biology the biology of movement locomotion in animals bones and movements muscle contraction

  1. Respiratory

  2. Skeletal

  3. Excretory

  4. Circulatory

Show answer
Correct Option: B

The joint between the carpal bones and tarsal bones is

biology skeleton - movement and locomotion locomotion in animals bones and movements muscle contraction

  1. Gliding joint

  2. Ball and socket joint

  3. Hinge joint

  4. Saddle joint

Show answer
Correct Option: A
Explanation:

A gliding joint is the simplest of the synovial joints. Gliding joints are found between the carpal bones and between the tarsal bones.

Which one of the following pairs is correctly matched?

biology movement and locomotion in living organisms locomotion in animals bones and movements muscle contraction

  1. Nutation- Movement due to injury

  2. Traumatotropism- Movement due to change in turgor pressure

  3. Thigmotropism- Movement of tendrils due to contact

  4. Seism nasty- Movement of stem tips of twining plants

Show answer
Correct Option: A

Which statements about muscle contractions are true?
(i) Acetylcholine is released when neural signal reaches motor end plate
(ii) Muscle contraction is initiated by a signal sent by CNS via a sensory neuron
(iii) During muscle contraction, isotropic band gets elongated
(iv) Repeated activation of the muscle can lead to lactic acid accumulation.

muscle contraction locomotion and movements biology

  1. i and iv

  2. i and iii

  3. ii and iii

  4. i, ii and iii

  5. i and ii

Show answer
Correct Option: A
Explanation:

  • Acetylcholine is the neurotransmitter used at the neuromuscular junction, it is the chemical that motor neurons of the nervous system release in order to activate muscles when acetylcholine is released when the neural signal reaches motor end plate. 
  • Repeated activation of muscle induces processes resulting in decreased performance (fatigue) as well as enhanced performance (potentiation).  Lactic acid is formed and accumulated in the muscle under conditions of high energy demand, rapid fluctuations of the energy requirement and insufficient supply of O2. Hence,  Repeated activation of the muscle can lead to lactic acid accumulation.
So, the correct answer is ' i and iv'.

In hurdle race, what is the major energy source of the leg muscle?

muscle contraction locomotion and movements biology

  1. ATP

  2. Glycolysis

  3. Pyruvate and lactate

  4. Oxidative metabolism

Show answer
Correct Option: A
Explanation:
  • The source of energy that is used to power the movement of contraction in working muscles is adenosine triphosphate (ATP).
  • ATP is considered as the energy currency of the cell.
  • Hence In a hurdle race, what is the major energy source of the leg muscle ATP. It helps in muscle contraction that facilitates running in the race.
  • So, the correct answer is 'ATP'.

Electron microscopic studies of the sarcomeres have revealed that during muscle contraction

muscle contraction locomotion and movements biology

  1. The width of A-band remains constant

  2. The width of the H-zone becomes smaller

  3. The width of I-band increases

  4. The diameter of the fibre increases

Show answer
Correct Option: A
Explanation:

During muscle contraction, the A - band with a length of 1.85 micrometers does not undergo any contraction. However, the I-bands and the H-zone shorten. This causes the Z lines to come closer together. So, the correct answer is 'The width of A-band remains constant'.

In hurdle race, what is major source of energy to leg muscle?

muscle contraction locomotion and movements biology

  1. Preformed ATP

  2. Oxidative metabolism

  3. Pyruvate and lactate

  4. Glycolysis

Show answer
Correct Option: B
Explanation:

  • In the hurdle race, a person requires energy production faster than our bodies can adequately deliver oxygen. 
  • In those cases, the working muscles generate energy anaerobically. This energy comes from glucose through a process called glycolysis, in which glucose is broken down or metabolized into a substance called pyruvate through a series of steps.
  •  When oxygen is limited, the body temporarily converts pyruvate into a substance called lactate, which allows glucose breakdown and thus energy production to continue.
  •  The working muscle cells can continue this type of anaerobic energy production at high rates for one to three minutes, during which lactate can accumulate to high levels.
Hence, In the hurdle race,  Oxidative metabolism is a major source of energy to the leg muscle.
   So, the correct answer is 'Oxidative metabolism'.

Which statement is correct for muscle contraction : - 

muscle contraction locomotion and movements biology

  1. Length of H-zone become decrease

  2. Length of A-band remains constant

  3. Length of I-band become increase

  4. Length of two Z-line become increase

Show answer
Correct Option: A,B
Explanation:
Upon muscle contraction, the A-bands do not change their length (1.85 micrometres in mammalian skeletal muscle), whereas the I-bands and the H-zone shorten. This causes the Z lines to come closer together.

So, the correct answer is 'A, B'.