Question

how cells are used in the body quick check
why do heart cells have different characteristics than skin cells? (1 point)
○ heart cells reproduce by mitosis.
○ heart cells express different genes than skin cells.
○ heart cells have different dna than skin cells.
○ heart cells reproduce by cell differentiation.

Explanation:

• Heart cells reproduce by mitosis: Incorrect. While heart cells do reproduce by mitosis (in some cases, though adult heart cell mitosis is limited), this doesn't explain the difference in characteristics. Mitosis is a general cell - division process for growth and repair in many cell types.
• Heart cells express different genes than skin cells: Correct. Gene expression is what leads to cell - type specific characteristics. Different cell types in the body (like heart and skin cells) have the same DNA (except for rare mutations), but they express (turn on or off) different sets of genes. For example, heart cells express genes related to muscle contraction (like those for cardiac myofilaments), while skin cells express genes for keratin production.
• Heart cells have different DNA than skin cells: Incorrect. In a multicellular organism like a human, all somatic cells (non - reproductive cells) have the same DNA (genome) at the start of development. Any differences in DNA between heart and skin cells would be due to mutations, which are not the normal cause of their characteristic differences.
• Heart cells reproduce by cell differentiation: Incorrect. Cell differentiation is the process by which unspecialized cells become specialized. Reproduction (cell division) of heart cells is mainly by mitosis (in early development more actively, and to a limited extent in adults). Cell differentiation is not a form of reproduction.

Answer:

Heart cells express different genes than skin cells.