Final answer:
The individual missing the paternal chromosome 9 and the maternal chromosome 11 has monosomy for chromosomes 9 and 11. Monosomy is when one chromosome is missing, which can lead to severe developmental issues or non-viability. This is in contrast to trisomy, such as in Down syndrome, where there is an extra chromosome.
Step-by-step explanation:
When an individual is missing the paternal chromosome 9 and the maternal chromosome 11, they are exhibiting forms of aneuploidy called monosomy. Specifically, the individual shows:
- Monosomy for chromosome 9 - one copy of chromosome 9 is missing.
- Monosomy for chromosome 11 - one copy of chromosome 11 is missing.
In humans, having the correct number (euploidy) is 22 pairs of autosomes and one pair of sex chromosomes. Monosomy occurs when a single chromosome is missing, which can result in severe developmental issues or non-viability of a zygote because essential genes are absent. For example, Down syndrome, characterized by an extra chromosome 21, results from trisomy, where individuals have three copies of a chromosome instead of the normal two.