the sequence of DNA that codes for a protein and thus determines a trait.

The scientific study of heredity

Term used to refer to an organism that has two different alleles for the same trait (Tt)

Term used to refer to an organism that has two identical alleles for a particular trait.  (TT or tt).

Also called purebred

Masks the other trait; the trait that shows if present

(Represented by a capital letter)

An organism with a recessive allele for a particular trait will only exhibit that trait when the dominant allele is not present; Will only show if both alleles are present

(Represented by a lower-case letter)

The genetic makeup of an organism; The gene (or allele) combination an organism has.

Example: Tt, ss, GG, Ww

The physical characteristics of an organism; The way an organism looks

Example: Curly hair, straight hair, blue eyes, tall, green

Diagram showing the gene combinations that might result from a genetic cross. Used to calculate the probability of inheriting a particular trait

how traits are passed down from parent to offspring

specific characteristics that vary from one individual to another

the chance that an event will occur

u  How do you find the probability of an event?

Situation in which one allele is not completely dominant over another

Situation in which both alleles of a gene contribute to the phenotype of the organism