Tag: locomotion and movements

Questions Related to locomotion and movements

During skeletal muscle contractions following events can occur:
I. I-band shortens
II. A-band shortens
III. H-zone shortens
IV. Sarcomere contract
V. ATP changes to ADP and Pi
Choose the option with incorrect events.

muscle contraction locomotion and movements biology

  1. Only I

  2. Only III

  3. IV and V

  4. Only II

Show answer
Correct Option: D
Explanation:

I-band consists of only thin filaments. A-band consists of both the thin and thick filaments. H-zone is the band of thick filament only. For skeletal muscle contraction following events occur:

1. The nerve impulse is transmitted to the sarcolemma and it causes release of calcium ions from sarcoplasmic reticulum.
2. These calcium bind to the troponin and tropomyosin rotates. 
3. Then, the myosin binds to the tropomyosin. 
4. ATP is hydrolysed to detach the myosin from the tropomyosin and muscle can be relaxed.
The shortening of I-band and H-zone causes the contraction of sarcomere. 
A-band does not change.
Hence, the correct answer is 'only II'

Which responce to overcooling does not does not involve muscle contraction?

muscle contraction locomotion and movements biology

  1. Blood vessels narrowing

  2. Hairs standing up

  3. Shivering

  4. Reduced sweating

Show answer
Correct Option: D
Explanation:

Blood vessels narrowing, hairs standing up and shivering are all because of contraction of muscles. While reduced sweating is due to non-activation of sweat glands from the hypothalamus.

So, the correct option is 'reduced sweating'.

Which cell organelle is associated with muscle contraction by release and uptake of $Ca^{2+}$ ions?

muscle contraction locomotion and movements biology

  1. Golgi apparatus

  2. RER

  3. Sarcoplasmic reticulum

  4. Lysosome

Show answer
Correct Option: C
Explanation:

SER is associated with muscle contraction by release and uptake of Ca ions because SER functions as the packaging structure which stores the Ca ions until its release.

So, the correct option is 'SER'.

Match the following and mark the correct option.

Column I Column II
A. Fast muscle fibres i. Myoglobin
B. Slow muscle fibres ii. Lactic acid
C. Actin filament iii. Contractile unit
D. Sarcomere iv. I-band
muscle contraction locomotion and movements biology

  1. A-i, B-ii, C-iv, D-iii

  2. A-ii, B-i, C-iii, D-iv

  3. A-iii, B-ii, C-iv, D-i

  4. A-ii, B-i, C-iv, D-iii

Show answer
Correct Option: A
Explanation:
a) Fast muscle fibres -  They have a large amount of myoglobin which is resistant to fatigue. 
b) Slow muscles fibres - These type of fibres show a slow 'tunic' contraction characteristic of postural muscles. The lactic acid is produced during muscle contraction.
c) Actin filament - The light bands present in myofibrils contain actin and is called I-band or isotropic band.
d) Sarcomere - It is the contractile unit of muscle fibres.

So, the correct answer is 'A-i, B-ii, C-iv, D-iii'.

Which one of the following option gives the correct categorisation of structure of contractile proteins ?

Actin  Myosin
1 Troponin Actinin
2 Troponin tropomyosin HMM and LMM
3 'G' - actin Tropomyosin
4 Tropomyosin troponin $Ca^{++}$ binding site
muscle contraction locomotion and movements biology

  1. 1

  2. 2

  3. 3

  4. 4

Show answer
Correct Option: A
Explanation:

Troponin is attached protein tropomyosin and lies within the groove between actin filaments in the muscle tissue. The calcium attaches the troponin which changes the shape exposing binding sites for myosin on the actin filament. So the correct answer is 1.

The energy of muscle contraction is most directly obtained from____________.

muscle contraction locomotion and movements biology

  1. Phosphocreatine

  2. ATP

  3. Anaerobic respiration

  4. Aerobic respiration

Show answer
Correct Option: B
Explanation:
Answer :
i) The contraction of skeletal muscles is an energy-requiring process. 
ii) To perform the mechanical work of contraction, actin and myosin utilize the chemical energy of the molecule Adenosine triphosphate (ATP).
iii) Adenosine triphosphate (ATP) is a complex organic chemical that provides energy to drive many processes in living cells, e.g. muscle contraction, nerve impulse propagation, and chemical synthesis. 
iv) Found in all forms of life, ATP is often referred to as the "molecular unit of currency" of intracellular energy transfer.

Therefore correct answer is option B- ATP.


In isometric contraction ;-

muscle contraction locomotion and movements biology

  1. Tone changed but length same

  2. Length changed but tone same

  3. Length and tone both same

  4. Length and tone both change

Show answer
Correct Option: A
Explanation:

Isometric is directly defined as ‘same length’ whereby ‘iso’ means the same and ‘metric’ means ‘length’ when referring to muscles. During isometric contractions, the muscle itself does not change in length while the tension never exceeds the load that must be carried. This means that while the muscle itself does not shorten, the tension will never exceed the opposing force.

Hence, the correct answer is 'Tone changed but length same'.

ATP provides energy for muscle contraction by allowing for

muscle contraction locomotion and movements biology

  1. An action potential formation in the muscle cell

  2. Cross bridge detachment of myosin from actin

  3. Cross bridge detachment of myosin to actin

  4. Release of $C{a^{ + 2}}$ from sarcoplasmic rectulum

Show answer
Correct Option: B
Explanation:
ATP enables the actin-myosin cross-bridge to detach, and release energy through its hydrolysis to enable the myosin head to return to its resting position.
So, the correct option is Cross bridge detachment of myosin from actin.

During muscular contraction, the myosin head binds to the exposed active sites on actin to form a?

muscle contraction locomotion and movements biology

  1. Motor unit

  2. Motor end plate

  3. Cross bridge

  4. None of the above

Show answer
Correct Option: A

Which of the following parts of the nephric tubule is incorrectly matched regarding osmotic concentration of filtrate in it?

muscle contraction locomotion and movements biology

  1. PCT - Isotonic

  2. Bowman's capsule - Hypotonic

  3. Ascending limp of loop of Henle - Hypotonic

  4. Descending limb of loop of Henle - Hypertonic

Show answer
Correct Option: A