Tag: movement and locomotion in man

Questions Related to movement and locomotion in man

All or none law is not applicable for?

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

  1. Single skeletal muscle fibre

  2. Single smooth muscle fibre

  3. Whole skeletal muscle

  4. Whole cardiac muscle

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Correct Option: A
Explanation:

The all or none law states that the strength of the stimuli will not decide the reaction of the muscle fibre. f the stimulus is more than a certain threshold they will fire.  Either there will be a full response or there will be no response at all.

As we know that the stimulus works by stimulating the action potential in the fivers. The action potential is always full and thus the response will be there if the threshold is crossed.
We now that the skeletal muscle are the ones that are in control of the conscious mind and the stimuli can affect them so this is applicable for the voluntary muscles.

So, the correct option is 'Single skeletal muscle fibre'

The thickness of a striated muscle fibre increases________.

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

  1. With age

  2. With exercise

  3. With material accumulation in it

  4. All of the above

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Correct Option: B

Striated muscles are found in

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

  1. Gall bladder

  2. Wall of bronchi

  3. Leg muscles

  4. Lungs

Show answer
Correct Option: C
Explanation:
Striated muscle plays an integral role in the formation of the structural framework of the body. It is the only muscle tissue under the direct conscious control of the cerebral cortex of the brain and hence is the voluntary muscle. All conscious movements of the body, including movement of limbs like the movement of arm, legs, facial expressions, eye movements, and swallowing are the products of the skeletal muscle tissue.
So, the correct answer is option C.

What is sarcomere?

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

  1. Part between two H-lines

  2. Part between two A-lines

  3. Part between two I-lines

  4. Part between two Z-lines

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Correct Option: A

Find out the correct sequence of muscle structures/components present one within the other 

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

  1. Muscle fibre $\longrightarrow $ Myofilament $\longrightarrow $ Muscle bundle $\longrightarrow $ Myofibril

  2. Muscle bundle $\longrightarrow $ Muscle fibre$\longrightarrow $ Myofibril $\longrightarrow $ Myofilament

  3. Muscle bundle $\longrightarrow $ Muscle fibre $\longrightarrow $ Myofilament $\longrightarrow $ Myofibril

  4. Muscle fibre $\longrightarrow $ Muscle bundle $\longrightarrow $ Myofilament $\longrightarrow $ Myofibril

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Correct Option: A

The protoplasmic segment of a striated muscle fibre is termed as

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

  1. Sarcoplasm

  2. Sarcomere

  3. Neuromere

  4. Metamere

Show answer
Correct Option: A
Explanation:

Sarcomere is the smallest contractile unit of striated muscle fibre. Sarcomere occurs as repeating units along the length of a myofibril, occupying the region between Z lines of the myofibril. 

Sarcoplasm is the cytoplasm of a muscle fibre. It is a water solution containing ATP and phosphogens, as well as the enzymes of intermediate and product molecules involved in many metabolic reactions. 
Neuromere is a metameric segment of CNS. 
Metamere is a linear series of primitively similar segments into which the body of higher invertebrate and vertebrate is divisible.

Contractile fibrils of muscles are called

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

  1. Neurofibrils

  2. Callogen fibres

  3. Myofibrils

  4. Yellow fibres

Show answer
Correct Option: C
Explanation:

  • Each muscle fibre(muscle cell) is lined by the plasma membrane called sarcolemma enclosing the sarcoplasm(cytoplasm of muscle fibre). 
  • The characteristic feature of the muscle fibre(muscle cell) is the presence of a large number of parallelly arranged filaments in the sarcoplasm called myofilaments or myofibrils.
  • Each myofibril is made up of two kinds of proteins. They are actin and myosin.
  • The function of the myofibril is to perform muscle contraction via the sliding-filament model. Hence Contractile fibrils of muscles are called myofibrils.
  • So, the correct answer is 'Myofibrils'.

End plate junction is present between

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

  1. Neuron and striated muscle

  2. Neuron and neuron

  3. Muscle and muscle

  4. Both B and C

Show answer
Correct Option: A
Explanation:

The area of contact between the ends of a large myelinated nerve fibre and a fibre of the skeletal muscle is called the motor end plate junction. It is also called as a neuromuscular junction or myoneural junction.
Thus, the correct answer is the option (A), 'Neuron and striated muscle'.

Sarcomere is the functional unit of contraction in a muscle fibre. Identify the portion of myofibril that constitutes a sarcomere

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

  1. Portion of myofibril between two successive Z-lines

  2. Portion of myofibril between two successive I-bands

  3. Portion of myofibril between two successive A-bands

  4. Portion of myofibril between two successive M-lines

Show answer
Correct Option: A
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 Sarcomere is considered as the functional unit of contraction in a muscle fibre.
  • So, the correct answer is 'Portion of a myofibril between two successive Z-lines'.

An animal cell with numerous nuclei is called

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

  1. Coenocyte

  2. Syncytial

  3. Plasmodium

  4. Both A and B

Show answer
Correct Option: B
Explanation:
  • Syncytial refers to a multinucleate condition where a single cell has more than one nucleus per cell i.e., multiple nuclei with a common cytoplasm.
  • It is caused primarily due to multiple cell fusions of uninuclear cells.
  • This condition usually arises when cells are infected with certain types of viruses (HIV, pneumoviruses etc.).
  • In animals, this condition is seen in skeletal muscles (large skeletal muscle fibres are formed by the fusion of individual muscle cells).
  • So, the correct answer is 'Syncytial'.