| A | B |
|---|
| gene | an instruction for a characteristic |
| chromosome | made up of many genes and found in nucleus of every cell |
| mitosis | type of cell division that occurs in all cells except sex cells |
| meiosis | type of cell division that produces gametes |
| discrete variation | 'either or' variation, eg left handed, widows peak |
| continuous variation | variation which is measurable, eg height, weight |
| 46 | number of chromosomes in human body cells |
| 23 | number of cells in human gametes |
| alleles | pair of genes |
| genotype | pattern of alleles for traits |
| phenotype | the way a characteristic actually appears |
| heterozygous | alleles are different |
| homozygous | alleles are both the same |
| dominant | an allele which is always expressed when present |
| recessive | an allele which is only expressed when dominant is not present |
| DNA | complex molecule of which genes are made up of |
| gametes | sex cells |
| crossing over | process that takes place during meiosis, which cause an exchange of mixing of genes |
| incomplete dominance | inheritance in which neither pair of alleles is dominant over the other, and effects are blended |
| chromatid | identical chromosome strands, resulting from splitting of chrosome |
