BIO Ch 12 Vocabulary - Understanding Heredity

Allele

one of the different forms of a gene

Gamete

reproductive cell

Gene

sequence of DNA that codes for a protein and determines a trait; factor that is passed down from parent to kid cell

Genetics

scientific study of heredity

Hybrid

Offspring between parents with different traits

Principle of dominance

Mendel’s 2nd conclusion, which states that some alleles are dominant and others are recessive

Segregation

Separation of alleles during gamete formation

Trait

a specific characteristic of an individual

Genotype

genetic makeup of an organism

Heterozygous

having two different alleles for a particular gene

Homozygous

having two identical alleles for a particular gene

Independent assortment

genes for different traits can segregate independently during the formation of gametes

Phenotype

physical characteristics of an organism

Probability

likelihood that a particular event will occur

Punnett square

diagram that can be used to predict the genotype and phenotype combinations of a genetic cross

Codominance

situation in which the phenotype produced by both alleles are completely expressed

Incomplete dominance

situation in which one allele is not completely dominant over another allele

Multiple allele

gene that has more than 2 alleles

Polygenic trait

trait controlled by 2 or more genes

Crossing-over

process in which homologous chromosome exchange portions of their chromatids during meiosis

Diploid

refer to a cell that contains 2 sets of homologous chromosomes

Haploid

term used to refer to a cell that contains one single set of genes

Homologous

refer to chromosomes in which one set comes from the male parent and the other from the female