Which Statement Correctly Describes Vitamin A

question 13

Multiple Choice

Which statement correctly describes vitamin A?

• A) Vitamin A is carried from the liver by retinol-binding protein and transthyretin in the blood.
• B) Nearly all cells have vitamin-A binding retinoid receptors.
• C) Within a cell, vitamin A is involved in gene expression and cell differentiation.
• D) All of the above statements are correct.

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Definitions:

Smooth Muscle

A type of muscle found in the walls of internal organs, such as the stomach and blood vessels, that contracts involuntarily.

Calcium-Calmodulin Complex

A complex formed when calcium ions bind to the protein calmodulin, playing a key role in various cellular processes.

Myofibrils

The basic rod-like unit of a muscle cell, composed of sarcomeres, which are responsible for the muscle's contractile properties.

Sarcomeres

The basic contractile units of muscle fiber, defined by the region between two Z lines, responsible for muscle contraction.