‘What determines the function of a specialized cell? A the type of RNA in the cell B the number of ribosomes in the cell C the active genes in the cell D the number of chromosomes in the cell’
The Correct Answer and Explanation is:
Correct Answer: C) the active genes in the cell
Explanation:
The function of a specialized cell is determined by which genes are active (expressed) in that cell. All the cells in a multicellular organism, such as a human, contain the same DNA and the same number of chromosomes. However, not all genes are turned on in every cell. Cells become specialized through a process called cell differentiation, during which specific sets of genes are activated or deactivated, leading to the development of distinct cell types with unique structures and functions.
Gene expression is the process by which information from a gene is used to produce a functional product, usually a protein. These proteins determine the cell’s structure and carry out most of its functions. For example, in muscle cells, genes that code for contractile proteins like actin and myosin are highly active. In contrast, in nerve cells, genes that code for neurotransmitter-related proteins are more active. This selective gene activity results in cells performing very different roles, even though their DNA is identical.
Option A (the type of RNA in the cell) is related to gene expression but is a result of which genes are active, not the cause of specialization. Option B (the number of ribosomes) affects the cell’s protein synthesis capacity but does not determine the type of cell. Option D (the number of chromosomes) is constant for nearly all cells of an organism and does not dictate the function of specialized cells.
Thus, it is the pattern of gene activity—that is, which genes are turned “on” or “off”—that gives each specialized cell its identity and function. This is a foundational concept in developmental biology and molecular genetics.
