| A | B |
|---|
| autosome | chromosome that is not a sex chromosome; choromosomes that are the same in males and females |
| crossing over | process in which homologous chromosomes exchange portions of their chromatids during meiosis |
| diploid | term used to refer to a cell that contains both sets of homologous chromosomes; every cell in the body except for sex cells |
| down syndrome | form of trisomy which involves 3 copies of chromosome 21; Down Syndrome produces mild to severe metal retardation and an increased susceptibility to many diseases and a higher frequency of birth defects |
| fertilization | process in sexual reproduction in which male and female reproductive cells join to form a new cell |
| gamete | sex cells (sperm, egg); specialized cell involved in sexual reproduction |
| haploid | term used to refer to a cell that contains only a single set of chromosomes and therefore only a single set of genes |
| homologous | pairs of chromosomes of the same number - each receives 1 chromosome from mom and 1 chromosome from dad; (think shoes in a closet) |
| karyotype | set of photographs of chromosomes grouped in order of pairs arranged by size and shape; can be used to determine gender and see if chromosomal disorders have occurred |
| meiosis | cutting chromosoomes in half by process that makes gametes (eggs, sperm); process by which the number of chromosomes per cell is cut in half through the separation of homologous chromosomes in a diploid cell |
| monosomy | only one copy of a chormosome; the presence of only one chromosome from a pair |
| nondisjunction | error in meiosis in which homologous chromosomes fail to separate |
| polar bodies | the 3 cells in females that are formed in meiosis, but not usually involved in reproduction |
| polyploidy | extra copy of all chromosomes; good in plants, not in animals; condition in which an organism has extra sets of chromosomes |
| reduction division | cell division that produces reproductive cells in sexually reproducing organisms |
| somatic | of the body; having to do with the body |
| tetrad | structure containing 4 chromatids that forms during meiosis |
| trisomy | too many of one chromosome; "three bodies"; occurs when 2 copies of an autosomal chromosome fail to separate during meiosis and an individual is born with 3 copies of a chromosome |
| Turner's Syndrome | disosrder that occurs among the sex chromosomes; women with Turner's syndrome usually only inherit 1 x chromosome and are infertile |
| zygote | fertilized egg |
