Question | Answer |
trait | characteristic that is inherited |
genetics | study of the hereditary patterns and variation of organisms |
purebred | type of organism whose ancestors are genetically uniform |
cross | mating of two organisms |
law of segregation | Mendel's first law, stating that:
1. organisms inherit two copies of genes, one from each parent
2. organisms donate only one copy of each gene in their gametes because the genes separate in gamete formation |
gene | specific region of DNA that codes for a particular protein |
allele | any of the alternative forms of a gene that occurs at a specific place on a chromosome |
homozygous | characteristic of having two of the same alleles at the same locus of sister chromatids |
heterozygous | characteristic of having two different alleles that appear at the same locus of sister chromatids |
genome | all of an organism's genetic material |
genotype | collection of all an organism's genetic information that codes for traits |
phenotype | collection of all an organism's physical characteristics |
dominant | allele that is expressed when two different alleles are present in an organism's genotype |
recessive | allele that is not expressed unless two copies are present in an organism's genotype |
Punnett square | model for predicting all possible genotypes resulting from a cross, or mating |
monohybrid cross | cross, or mating, between organisms involving only one pair of contrasting traits |
testcross | cross between an organism with an unknown genotype and an organism with a recessive phenotype |
dihybrid cross | cross, or mating, between organisms involving two pairs of contrasting traits |
law of independent assortment | Mendel's second law, stating that allele pairs separate from each other during gamete formation |
probability | likelihood that a particular event will happen |
crossing over | exchange of chromosome segments between homologous chromosomes during meiosis 1 |
genetic linkage | tendency for genes located close together on the same chromosome to be inherited together |