| A | B |
|---|
| DNA | macromolecule; condenses around histones to create chromosomes |
| genome | an individual's collection of chromosomes; chromosomal library |
| chromosome | a unit of DNA wound around histone proteins |
| karyotype | a form on which metaphase chromosomes are arranged by size, centromere location and banding patterns |
| homologous | members of a pair of chromosomes; hold same genes but not necessarily the same trait for which the gene codes |
| loccus | a gene's address on a chromosome; ex. 7q2,3 |
| allele | alternate forms of a gene at a given loci; ex. B or b |
| homozygous | when the alleles for a given gene are the same; ex. BB or bb |
| genotype | actual alleles for a given gene |
| phenotype | the expressed trait determined by the pair of alleles for a gene |
| gene frequency | the rate of occurance for a given allele in a population |
| carrier frequency | the rate of occurance in a population of individuals that are heterozygous |
| dominant | the allele that is expressed in a heterozygous situation |
| recessive | the allele that is not expressed in a heterozygous situation |
| pedigree | a family tree |
| polygenic | the interaction of many genes to determine a trait |
| 1st degree relative | family member with which one shares 1/2 of their genes; siblings & parents |
| 2nd degree relative | family member with which one shares 1/4 of their genes; grand parents, aunts, uncles |
| 3rd degree relative | family member with which one shares 1/8 of their genes; great grandparents, great aunts & uncles, cousins |
| autosome | any chromosome of the first through twenty-second pairs |
| sex chromosome | the 23rd pair of chromosomes |
| maternal | referring to the mother |
| paternal | referring to the father |
| heterozygous | when the alleles for a given gene are the same; ex. Bb |
| autosomal recessive | a condition that presents itself only when both recessive genes are present and located on an autosome (ex. cystic fibrosis, tay-sachs) |
| autosomal dominant | a condition that presents itself when a dominant gene is present and located on an autosome (ex. Huntington's, Marfan's) |
| sex-linked | a condition whose genes are located on the sex chromosomes (probably the X); expressed more frequently in males |
| gene | a unit of DNA that codes for a trait |
| Tuffy | extra credit code word |
