Cell division in sexually reproducing organisms that forms gametes Consists of two rounds of cell division but only one round of DNA replication Results in four cells with haploid chromosome number

Paired chromosomes. the same size, shape, and carry genes for the same traits

Complete set of paired chromosomes

found in somatic (body) cells

2n

1 chromosome from each homologous pair

found in reproductive cells

1n

All other chromosomes except sex chromosomes

Determines gender Male= XY Female= XX

Reproductive cell Contains haploid # of chromosomes Generated during meiosis

Body cell Contains diploid # of chromosomes Generated during mitosis

Exchange of genetic material between homologous chromosomes

Diploid cell produced by the union of haploid gametes (egg and sperm) during fertilization

Organisms that produce offspring of the same variety over many generations of self-pollination.homozygous

True-breeding (homozygous) parent individuals from which F1 hybrid offspring are derived. "p" stands for parental

Hybrid (heterozygous) offspring arising from a parental (P generation) cross

Heterozygous

Different versions of a gene Ex: A or a

Genetic makeup of an individual

Physical traits

Having different alleles for a gene Ex: Aa

Having identical alleles for a gene Ex: AA or aa

Two alleles for a trait separate (segregate) during gamete formation and end up in different gametes

Each pair of alleles segregates independently of each other pair of alleles during gamete formation Traits are independent and require own Punnett square

Crossing an organism with recessive individual

A cross between two organisms that are heterozygous resulting in 3:1 ratio of dominant to recessive phenotypes

A cross between two organisms that are heterozygous for TWO traits resulting in a 9:3:3:1 ratio

Traits that involve multiple genes Ex: eye, skin, and hair color

Traits that have more than two alleles contributing to phenotype Ex: blood type

A gene located on either sex chromosome Most sex-linked genes are on the X chromosome

Phenotype that most commonly observed in natural populations

Offspring with non-parental phenotypes (new combinations of traits) due to crossing over between linked genes

Divide total number of recombinants (non-parental phenotypes) by the total number of offspring

Genes located close enough together on a chromosome that they tend to be inherited together

A genetic map of a chromosome based on recombination frequencies

Distances between genes. one map unit represents a 1% recombination frequency

The failure of one or more pairs of homologous chromosomes or sister chromatids to separate normally during meiosis

A chart or "family tree" that tracks which members of a family have a particular trait