Question

identify chromosomal disorder
identify the type of chromosomal abnormality described below.
a person has a missing copy of the x chromosome.
a baby has an extra copy of chromosome 18.
a fetus is found to have four copies of chromosome 1.
polyploidy
aneuploidy

Explanation:

• A person has a missing copy of the X chromosome: This is an example of aneuploidy. Aneuploidy is the condition where there is an abnormal number of chromosomes in a cell (either extra or missing). In this case, there is a missing chromosome (the X chromosome).
• A baby has an extra copy of chromosome 18: This is also aneuploidy. Here, there is an extra chromosome (chromosome 18).
• A fetus is found to have four copies of chromosome 1: This is aneuploidy. Aneuploidy can involve having more than the normal number of a particular chromosome (in this case, four copies of chromosome 1 instead of the normal two). Polyploidy would involve having an entire extra set of chromosomes (e.g., triploid - 3 sets, tetraploid - 4 sets of all chromosomes), which is not the case here as it is only an extra number of a single chromosome (chromosome 1).

Answer:

• A person has a missing copy of the X chromosome: aneuploidy
• A baby has an extra copy of chromosome 18: aneuploidy
• A fetus is found to have four copies of chromosome 1: aneuploidy