According to the Sliding-Filament Model of Contraction, How Does Muscle

question 22

Multiple Choice

According to the sliding-filament model of contraction, how does muscle contraction occur?

• A) The myosin heads propel the actin myofilaments toward the center of the sarcomere; this pulls the Z disks closer together, which shortens the sarcomere and the entire muscle.
• B) The actin heads propel the myosin filaments toward the center of the sarcomere; this pulls the Z disks closer together, which shortens the sarcomere and the entire muscle.
• C) The myosin heads propel the actin myofilaments toward the center of the sarcomere. This causes the myofilaments to shorten, which pulls the Z disks closer together to shorten the sarcomere and the entire muscle.
• D) Both the actin and myosin myofilaments shorten, which shrinks the sarcomere and pulls the Z disks closer together. As the Z disks move closer together, the muscle contracts.

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Definitions:

Specific Gravity

The ratio of the density of a substance to the density of a reference substance; commonly used in various scientific fields to characterize the physical properties of fluids.

Specimen

A sample of tissue, blood, urine, or other material from the body used for analysis and diagnosis.

Urine Color

The hue or shade of urine, which can vary based on hydration levels, the presence of certain substances, or health conditions.

Specific Gravity

The ratio of the density of a substance to the density of a reference substance, typically water.