Ch4 Genetics Vocab

Heredity

The passing of traits from parent to offspring

Trait

a specific characteristic of an individual organism that can pass to its offspring; through genes (?)

Genetics

The scientific study of heredity

Fertilization

Process in sexual reproduction when an egg and sperm cells join to form a new cell

Purebred

the offspring of many generations that have the same form of a trait

Gene

to describe the factors that control a trait

Allele

Different forms of a gene

dominant allele

one trait always shows up in the organism when the allele is present

recessive allele

An allele that is HIDDEN whenever the dominant allele is present

Hybrid

An organism that has TWO different alleles for a trait

Probability

A number that describes how likely it is that an event will occur

Punnett Square

A chart that shows all the possible combinations of alleles that can result from a genetic cross

Phenotype

An organism's physical appearance, or visible traits.

Genotype

An organism's genetic makeup, or allele combinations.

Homozygous

An organism that has *two identical* alleles for a trait

Heterozygous

An organism that has *two different* alleles for a trait

incomplete dominance

A pattern of inheritance in which two alleles, inherited from the parents, are neither dominant nor recessive. The resulting offspring have a phenotype that is a *blending* of the parental traits. **Allele is only partially dominant**

Codominance

A condition in which both alleles for a gene are fully expressed equally

multiple alleles

three or more possible alleles of the same gene to determine the trait

Meiosis

process in which the number of chromosomes per cell is cut in half through the separation of homologous chromosomes in a diploid cell