Question

cells within an organism can be very different from one another. for example, human red blood cells are filled with hemoglobin, are shaped like biconcave discs, lack a cell nucleus, and cannot synthesize proteins. human muscle cells, on the other hand, are cylindrical in shape and have multiple nuclei.
cell specialization in the human body is usually due to
oa. radiation by high energy photons that mutates the cells of the body into different shapes.
ob. different cells within the human body exhibiting different patterns of gene expression.
oc. mistakes that occur during dna replication that result in framework mutations in the cells.
od. different cells within the human body containing different, unique dna sequences.

Explanation:

Cell specialization in the human body occurs because different cells express different genes. Gene expression patterns determine the structure and function of cells. For example, red blood cells express genes related to hemoglobin production, while muscle cells express genes for muscle - specific proteins. Mutations (options A and C) are not the normal cause of cell specialization. And all somatic cells in the human body (except gametes) have the same DNA sequence (so option D is incorrect).

Answer:

B. different cells within the human body exhibiting different patterns of gene expression.