Video Transcript
A normal human cell contains 46
chromosomes in total, 23 inherited from the father and 23 inherited from the
mother. Each group of 23 chromosomes is
called a set of chromosomes. A normal human cell, therefore, has
two sets of chromosomes. In some organisms, entire
chromosome sets have been duplicated. What term is given to a cell in an
organism that has more than two sets of chromosomes?
This question is asking us about a
situation where an organism contains more than two sets of chromosomes. Let’s review some terms related to
chromosomal composition in order to answer this question correctly.
DNA in our cells is organized into
structures called chromosomes. As mentioned in the question, human
cells contain 46 chromosomes in total, or two sets of 23 chromosomes. You can see one chromosome pair
here containing a single chromosome from each of the two sets. We get one set from our biological
mother and the other from our biological father. This is true for most of the cells
in our body. Cells that contain two copies of
each chromosome are called diploid. The prefix di- in “diploid” means
two.
However, not all cells in our body
contain a diploid set of chromosomes. Our sex cells, like sperm or egg
cells, contain only a single set. This is because once they combine
during fertilization, the full diploid set is made. This is called a haploid number of
chromosomes. Sometimes, an organism can contain
more than two sets of chromosomes. Some organisms, for example, can
have three sets of chromosomes. Organisms that have more than two
sets of chromosomes are called polyploids. These organisms tend to have a lot
of duplicated genetic information. And this is typically not tolerated
in humans and can be detrimental. However, many plants are polyploid
without issue.
To get back to our question, the
term that is given to a cell in an organism that has more than two sets of
chromosomes is polyploid.
