Structural Organisation In Animals Question 456
Assertion : Muscle cells are also called muscle fibers. Reason : Muscle cells are very thin and elongated.
Options:
A) If both the assertion and the reason are true and the reason is a correct explanation of the assertion
B) If both the assertion and reason are true but the reason is not a correct explanation of the assertion
C) If the assertion is true but the reason is false
D) If the assertion is false but reason is true
Show Answer
Answer:
Correct Answer: D
Solution:
Since muscle cells are very thin and elongated, therefore, they are also called as muscle fibres and not myofibrils.
Myofibril is the unit of a striated muscle cell.
A striated muscle fibre is composed of many myofibrils arranged along the long axis of the fibre.
A myofibril is of two types of myofilaments-actin filaments and myosin filaments.
Sliding of these myofilaments over one another causes the contraction and relaxation of the muscle fibre.
BETA
