Question

1 multiple choice 1 point
which one of the following statements correctly describes activities of muscles?
all muscles are synergistic.
all muscles are attached to bones.
all muscles produce limb movement.
all muscles shorten when they contract.
all muscles are under conscious control.

2 multiple choice 1 point
skeletal muscle groups that work together to create the same movement of a body part are referr
involuntary.
myofibrils.
synergistic.

Explanation:

For Question 1:

• "All muscles are synergistic": Incorrect, as muscles can also be antagonistic (oppose movement).
• "All muscles are attached to bones": Incorrect, e.g., smooth muscles in organs have no bone attachments.
• "All muscles produce limb movement": Incorrect, e.g., cardiac muscle moves blood, not limbs.
• "All muscles shorten when they contract": Correct, muscle contraction (sliding filament theory) reduces muscle length.
• "All muscles are under conscious control": Incorrect, cardiac and smooth muscles are involuntary.

For Question 2:

• "involuntary": Refers to muscle control, not coordinated movement.
• "myofibrils": Structural units within muscle fibers, not muscle groups.
• "synergistic": Defines muscle groups that work together for the same movement.

Answer:

1. All muscles shorten when they contract.
2. synergistic.