Tag: bones and movements

Questions Related to bones and movements

Upon stimulation of skeletal muscles, calcium is immediately made available for binding to troponin from :

biology locomotion and movement locomotion in animals bones and movements muscle contraction types of muscles muscles

  1. Blood

  2. Lymph

  3. Sacroplasmic reticulum

  4. Bone

Show answer
Correct Option: C
Explanation:

Answer is option C i.e. "Sacroplasmic reticulum"
Neurotransmitter acetylcholine generates an action potential in the sarcolemma causing the release of calcium ions into the sarcoplasm from the sarcoplasmic reticulum.
When Ca++ level increases it leads to the binding of calcium with a sub-unit of troponin on actin(thin) filaments and thereby activating the movement.

An iron-containing protein myoglobin is present in the

biology locomotion and movement locomotion in animals bones and movements muscle contraction types of muscles muscles

  1. Spleen

  2. Lungs

  3. Muscles

  4. None of the above

Show answer
Correct Option: C
Explanation:

Myoglobin is the iron and oxygen-binding protein that is found in the muscle tissue of the vertebrates and in almost all mammals. This contains heme, the pigment responsible for the red color of meat.

Therefore, the correct answer is option C.

What would be the result of an allele that codes for all actin molecules to be synthesized in linear chains?

biology locomotion and movement locomotion in animals bones and movements muscle contraction types of muscles muscles

  1. Immovable muscles

  2. Smooth muscle tissue

  3. Normal sarcomere structure

  4. Degeneration of muscle tissue

  5. Muscle tendons that cannot attach

Show answer
Correct Option: C
Explanation:

Sarcomere is the structural and functional unit of a myofibril and consists of thick myosin filaments and thin actin filaments. If the allele for actin filament continues to synthesize linear chains of the protein, sarcomere structure would be same as normal. Thus, the correct answer is option C.

Which of the following is the result of synthesis of actin molecule(coded by allele) in a linear chain?

biology locomotion and movement locomotion in animals bones and movements muscle contraction types of muscles muscles

  1. Immovable muscles

  2. Smooth muscle tissue

  3. Normal sarcomere structure

  4. Degeneration of muscle tissue

  5. Muscle tendons that cannot attach

Show answer
Correct Option: C
Explanation:
  • A sarcomere is the functional unit (contractile unit) of a muscle fibre. 
  • Each sarcomere contains two types of myofilaments: thick filaments, composed primarily of the contractile protein myosin, and thin filaments, composed primarily of the contractile protein actin. Hence, Normal sarcomere structure is the result of the synthesis of actin molecule(coded by allele) in a linear chain.
So, the correct answer is 'Normal sarcomere structure'.
 

The binding of troponin to calcium in muscle cells exposes the binding site of

biology locomotion and movement locomotion in animals bones and movements muscle contraction types of muscles muscles

  1. Tropomyosin

  2. Myosin

  3. ATP

  4. ADP

  5. ${P} _{i}$

Show answer
Correct Option: B
Explanation:

  • Muscle contraction thus results from an interaction between the actin and myosin filaments that generates their movement relative to one another. 
  • The molecular basis for this interaction is the binding of myosin to actin filaments, allowing myosin to function as a motor that drives filament sliding. Hence, The binding of troponin to calcium in muscle cells exposes the binding site of Myosin.
So, the correct answer is 'Myosin'.

${Ca}^{2+}$ and ${Mg}^{2+}$ ions 

biology locomotion and movement locomotion in animals bones and movements muscle contraction types of muscles muscles

  1. Reduce excitability of nerves and muscles.

  2. Increase excitability of nerves and muscles.

  3. Conduct nerve impulses.

  4. Both B and C.

Show answer
Correct Option: A
Explanation:

High calcium and magnesium ion concentration decrease the excitability of the muscle fiber membrane by raising the threshold to stimulation, while a low level of the calcium and magnesium ions increase the excitability of muscles fibers. 
So, the correct answer is A.

ATP-ase needed for muscle contraction is present over

biology locomotion and movement locomotion in animals bones and movements muscle contraction types of muscles muscles

  1. Aetinin

  2. Troponin

  3. Myosin

  4. Actin

Show answer
Correct Option: C
Explanation:

ATPase needed for muscle contraction is present over the myosin. Myosin binds to actin at a binding site. Myosin has another binding site for ATP at which enzymatic activity of myosin ATPase hydrolyzes ATP to ADP which releases an inorganic phosphate molecule and energy. The energy released during ATP hydrolysis changes the angle of the myosin head into a cocked position. The myosin head is then in a position for further movement possessing potential energy. The enzyme myosin ATPase catalyses the reaction in the presence of Ca$^{2+}$ and Mg$^{2+}$. So, the correct answer is 'Myosin'.

Which of these ions are involved in muscle contraction? 

biology locomotion and movement locomotion in animals bones and movements muscle contraction types of muscles muscles

  1. $Ca^{2+}$ and $Mg^{2+}$

  2. $Ca^{2+}$ and $Na^+$

  3. $Na^+$ and $K^+$

  4. $Mg^{2+}$ and $K^+$

Show answer
Correct Option: A
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. 
  • 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.
  • Magnesium also plays a role in regulating muscle contractions. Magnesium acts as a natural calcium blocker to help muscles relax. Hence Ca++ and Mg++ ions are involved in muscle contractions.
  • So, the correct answer is 'Ca$^{2+}$ and Mg$^{2+}$'.

The cartilage making up the lower jaw is known a

biology locomotion and movement locomotion in animals bones and movements muscle contraction types of muscles muscles

  1. Dentary

  2. Metapophysis

  3. Anapophysis

  4. Post-zygapophysis

Show answer
Correct Option: C
Explanation:

Lower jaw or II part of mandibular arch is cartilage nous initially and is called nickel's cartilage, which soon changes into bony structure.

The immediate regeneration of ATP  used up during muscle
contraction is facilitated by

biology locomotion and movement locomotion in animals bones and movements muscle contraction types of muscles muscles

  1. Glucose

  2. Glycogen

  3. Lactic acid

  4. Creatine phosphate

Show answer
Correct Option: D
Explanation:

The excess ATP is used to synthesize creatine Phosphate, an energy rich molecule that is found in muscle fibres.