Unit 4 Vocabulary

the different possibilities for a given trait

• Allele

• Genes

• DNA

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

• Allele

• Gene

• DNA

The scientific study of heredity

• Genes

• Trait

• Genetics

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

• Heterozygous

• Homozygous

• Recessive

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

Also called purebred

• Heterozygous

• Homozygous

• Dominant

Masks the other trait; the trait that shows if present

(Represented by a capital letter)

• DNA

• Recessive

• Dominant

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)

 

• Recessive

• Dominant

• Homozygous

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

Example: Tt, ss, GG, Ww

• Recessive

• Genotype

• Phenotype

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

 

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

• Phenotype

• Gentype

• Heredity

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

• Heredity

• Traits

• Punnett Square