Final answer:
Haploid cells have half the number of chromosomes as diploid cells. Tetraploid cells have four complete sets of chromosomes. Trisomy refers to an extra copy of a chromosome, and monosomy refers to the loss of one copy of a chromosome.
Step-by-step explanation:
Haploid, tetraploid, trisomic, and monosomic are terms used in genetics to describe the number of chromosomes in a cell.
A haploid cell has half the number of chromosomes compared to a diploid cell. In humans, a diploid cell has 46 chromosomes, while a haploid cell has 23 chromosomes. Haploid cells are typically found in gametes (sperm and eggs) and are involved in sexual reproduction.
A tetraploid cell, on the other hand, has four complete sets of chromosomes. This is often the result of errors in cell division, leading to the doubling of chromosomes. Tetraploidy is relatively rare in humans but can occur in certain types of cells, such as liver cells.
Trisomy refers to the presence of an extra copy of a chromosome, resulting in a total of three copies of that chromosome instead of the usual two. Down syndrome, for example, is caused by trisomy of chromosome 21. Trisomy can lead to various developmental and health issues.
Monosomy, on the other hand, refers to the loss of one copy of a chromosome, leading to a total of just one copy instead of the usual two. Monosomy is generally not compatible with life, as it often results in the loss of essential genes.