How many chromosomes do humans have in a diploid cell?

Humans have 46 chromosomes in a diploid cell, which is the correct answer. This total consists of 23 pairs of chromosomes. Each pair contains one chromosome inherited from the mother and one from the father. In diploid organisms like humans, the diploid condition provides two complete sets of chromosomes, allowing for genetic diversity and stability across generations. The number 46 reflects the normal complement of chromosomes found in somatic (non-reproductive) cells of the human body.

In contrast, other numbers listed in the choices do not represent the correct diploid number for humans. For instance, 23 represents the number of chromosomes in a haploid cell (such as sperm or egg cells), while 12 and 24 do not align with the known chromosomal structure of humans. Understanding the significance of being diploid helps to clarify why the total number of chromosomes is 46 in human cells.