Final answer:
A cell with 2n + 1 chromosomes is an example of aneuploidy, specifically known as trisomy, which often results in developmental disorders like Down Syndrome. So, the correct answer is option e.
Step-by-step explanation:
A cell with 2n + 1 chromosomes is an example of aneuploidy. This type of chromosomal variation occurs due to errors during cell division, specifically nondisjunction during meiosis, leading to gametes with abnormal numbers of chromosomes.
When a gamete with an extra chromosome (n+1) fuses with a normal gamete (n), the resulting zygote will have an extra chromosome, resulting in trisomy, which is aneuploid. Trisomy often leads to developmental issues and is most survivable when it involves smaller chromosomes, such as chromosome 21 which leads to Down Syndrome.
So, the correct answer is option e.