Question

There are different types of human blood cells. Depending on what type they are, some blood cells either carry nutrients throughout the body or destroy foreign substances in the body. Which statement explains how genes control the differentiation of different types of blood cells?

A Different genes are expressed in the different types of blood cells.

B Some genes are deleted in one type of blood cell, changing the type of cell it is.

C Specific genes in blood cells are expressed only in response to an external environmental change.

D Genes found in all blood cells can change the cell to perform any function needed.​

Answer 1

The correct statement explaining how genes control the differentiation of blood cells is that different genes are expressed in different types of blood cells (Option A). This gene expression dictates the specific function and type of each blood cell, such as red or white blood cells.

Step-by-step explanation:

The differentiation of different types of blood cells is controlled by the expression of different genes. This process is similar to actors reading only their parts of a script; although every cell has the same DNA, each cell type expresses only the subset of genes that pertain to its unique function. Therefore, the correct statement that explains how genes control the differentiation of different types of blood cells is: A. Different genes are expressed in the different types of blood cells.

In the context of blood cells, this means that stem cells in the red bone marrow will differentiate into various types of blood cells (e.g., red blood cells, white blood cells, platelets) depending upon which genes are activated. Disorders such as leukemia, hemophilia, and anemia arise from issues related to these differentiation processes and gene expressions. Furthermore, blood type is genetically determined and is generally consistent throughout an individual's life unless a bone marrow transplant occurs, which may change the recipient's blood type to that of the donor's.