Question

Muscle cells produce myofibrillar proteins, such as actin and myosin, which are important to the muscle fiber structure and function. Bone cells do not produce these proteins.

Why does this specialization occur?

Responses

The genes in muscle cells are totally different from those in bone cells.
The genes in muscle cells are totally different from those in bone cells.

Different genes are active in muscle cells than are active in bone cells.
Different genes are active in muscle cells than are active in bone cells.

Muscle cells contain a nucleus with DNA, while bone cells do not.
Muscle cells contain a nucleus with D N A , while bone cells do not.

Muscle cells contain recombinant DNA, while bone cells do not.

Answer 1

The correct response is:

**Different genes are active in muscle cells than are active in bone cells.**

This specialization occurs because muscle cells and bone cells have different functions and therefore express different sets of genes that code for the proteins specific to their roles. Muscle cells need to produce myofibrillar proteins like actin and myosin for contraction, while bone cells have a different set of genes that allow them to produce proteins important for bone structure and function.