Video Transcript
How many chromosomes should appear
in a karyotype of a human diploid body cell?
Let’s first define some key
terms. A chromosome is a structure found
in the nucleus of cells that consists of highly coiled and condensed DNA. Humans, like most other animals,
carry multiple chromosomes in the nucleus of their cells. Human cells and those of most
animals are diploid, meaning that there are two chromosomes of each type carried in
the nucleus of a cell.
Diploid cells are often referred to
as 2n, where n is the number of sets or pairs. Since there are two chromosomes in
each set, the total number of chromosomes will be twice the number of sets. For each of these sets, or pairs,
of chromosomes, one chromosome was inherited from that individual’s biological
mother and the other was inherited from that individual’s biological father. Together, these two copies of each
chromosome result in the individual’s diploid cell.
It’s important to remember again
that humans have many sets of chromosomes, so this is true of each set. In fact, humans have 23 sets of
chromosomes that they carry in their cells. Since there are two chromosomes in
each of these 23 sets, that means there are 46 chromosomes in all.
A karyotype is a photograph of all
of the chromosomes in a cell, organized into chromosomal pairs, or sets. So this might be what a karyotype
would look like for an organism with only five chromosomal sets. We are asked in this question about
a human diploid body cell. So the correct answer to this
question is 46. The number of chromosomes that
should appear in a karyotype of a human diploid body cell is 46.
