Tag: skeleton and movements

Questions Related to skeleton and movements

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'. 

During heavy exercise, we get cramps in the legs due to the accumulation of

zoology skeleton and movements features of a muscle muscle features muscle contraction and its effects

  1. Carbon dioxide

  2. Lactic acid

  3. Alcohol

  4. Water

Show answer
Correct Option: B
Explanation:
  • During heavy exercise, the demand for energy is high but the supply of oxygen to produce energy is limited. Therefore, anaerobic respiration takes places in the muscles cells to fulfil the demand for energy. This anaerobic breakdown of glucose leads to the formation of lactic acid in muscles. The accumulation of lactic acid in muscles leads to muscle cramps.
  • HenceDuring heavy exercise, we get cramps in the legs due to the accumulation of Lactic acid.
  • So, the correct answer is 'Lactic acid'.

Glycogen is degraded to lactic acid by enzymes in muscles and liver when the animal is

zoology skeleton and movements features of a muscle muscle features muscle contraction and its effects

  1. Exhausted

  2. Starved

  3. Killed

  4. Defaecated

  5. Copulated

Show answer
Correct Option: A
Explanation:
  • Glucose is the major source of energy in the body. excess glucose is stored in the form of glycogen in muscles and liver.
  • Most of the glycogen is stored in liver i.e 10 % of the mass of liver and the muscles contain a low amount of glycogen i.e 1% of the muscle mass.
  • When the glucose is completely utilized the animal feels exhausted, to overcome this the glycogen is degraded to lactic acid by enzymes in muscles and liver. 
  • So, the correct answer is 'Exhausted'.

Muscles get fatigued due to accumulation of

zoology skeleton and movements features of a muscle muscle features muscle contraction and its effects

  1. Adenosine triphosphate

  2. $CO _2$

  3. Lactic acid

  4. Phosphate molecules

Show answer
Correct Option: C
Explanation:
  • The Burning of glucose during respiration requires oxygen. When a Muscle is subjected to continuous exercise there will be low availability of oxygen. This leads to the anaerobic breakdown of glucose which results in the formation of lactic acid. 
  • This accumulation of lactic acid in the muscle causes muscle fatigue.
  • Hence Muscles get fatigued due to the accumulation of lactic acid.
  • So, the correct answer is 'Lactic acid'.

Rigor mortis in due to

zoology skeleton and movements features of a muscle muscle features muscle contraction and its effects

  1. Depletion of ATP

  2. Excess ATP

  3. Excess availability of calcium

  4. Release of magnesium

Show answer
Correct Option: A
Explanation:
  • Regor mortis is one of the recognizable signs of death, caused by the depletion of ATP followed by the chemical changes in muscles after death, causing the body to stiffen and locked in place, making it difficult to move and manipulate.
  • When the ATP is depleted muscles can not contract and the body becomes stiff.
  • It takes about 2 days for rigor mortis to fade, and once it does, decay sets in.
  • Hence rigor mortis is due to depletion of ATP.
  • So, the correct answer is 'Depletion of ATP'.

All or none law is not applicable for

zoology skeleton and movements features of a muscle muscle features muscle contraction and its effects

  1. Single skeletal muscle fibre

  2. Whole skeletal muscle

  3. Single smooth muscle fibre

  4. Whole cardiac muscle

Show answer
Correct Option: B
Explanation:
  • The all-or-none law is the principle that the strength by which a nerve or muscle fibre responds to a stimulus is independent of the strength of the stimulus. If that stimulus exceeds the threshold potential, the nerve or muscle fibre will give a complete response; otherwise, there is no response.
  • Hence All or none law is not applicable for whole skeletal muscle.
  • So, the correct answer is 'Whole skeletal muscle'.

Lactic acid deposition leads to

zoology skeleton and movements features of a muscle muscle features muscle contraction and its effects

  1. Tetany

  2. Muscle fatigue

  3. Muscle strain

  4. Convulsions

Show answer
Correct Option: B
Explanation:
  • Generally, the glucose undergoes metabolism in the presence of oxygen to form ATP(adenosine triphosphate) which is essential for the muscle contraction but during vigorous exercise, the body cannot meet the oxygen demand and the glucose undergoes metabolism in the absence of oxygen which results in the formation and accumulation of lactic acid.
  • Feeling of fatigue after vigorous exercise for some time is due to the accumulation of lactic acid in muscles.
  • Hence lactic acid deposition leads to muscle fatigue.
  • So, the correct answer is 'Muscle fatigue'.

All or none law is associated with

zoology skeleton and movements features of a muscle muscle features muscle contraction and its effects

  1. Muscle fibre

  2. Neuron

  3. Uriniferous tubule

  4. Both A and B

Show answer
Correct Option: D
Explanation:
  • The all-or-none law is a principle that states that the strength of a response of a nerve cell(neuron) or muscle fibre is not dependent upon the strength of the stimulus. If a stimulus is above a certain threshold, a nerve or muscle fibre will fire.
  • Hence All or none law is associated with muscle fibre and neuron.
  • So, the correct answer is 'Both A and B'.

In the anaerobic reaction of muscle, lactic acid is produced which causes painful tiredness. Where and by which mechanism lactic acid is catabolized?

zoology skeleton and movements features of a muscle muscle features muscle contraction and its effects

  1. In muscle by monokinase action

  2. In muscle by Lohmans reaction

  3. In liver by Cori cycle

  4. In liver by phosphogen reaction

Show answer
Correct Option: C
Explanation:
  • Generally, the glucose undergoes metabolism in the presence of oxygen to form ATP (Adenosine triphosphate) which is essential for the muscle contraction but during strenuous exercise, the body cannot meet the oxygen demand and the glucose undergoes metabolism in the absence of oxygen which results in the formation and accumulation of lactic acid.
  • This accumulated lactic acid is moved to the liver and converted into glycogen thorough Cori cycle.
  • Cori cycle takes place in the liver.
  • Hence In the anaerobic reaction of muscle, lactic acid is produced which causes painful tiredness. The lactic acid accumulated is catabolized by the mechanism of the Cori cycle in the liver.
  • So, the correct answer is 'In liver by Cori cycle'

Lactic acid generated during muscle contraction is elaborated to form glycogen in

zoology skeleton and movements features of a muscle muscle features muscle contraction and its effects

  1. Liver

  2. Pancreas

  3. Kidney

  4. Muscle

Show answer
Correct Option: A
Explanation:
  • Generally, the glucose undergoes metabolism in the presence of oxygen to form ATP(adenosine triphosphate) which is essential for the muscle contraction but during vigorous exercise, the body cannot meet the oxygen demand and the glucose undergoes metabolism in the absence of oxygen which results in the formation and accumulation of lactic acid.
  • This Lactic acid generated during muscle contraction is elaborated to form glycogen in Liver through Cori cycle.
  • So, the correct answer is 'Liver'.