Frayer Model

Vocabulary Review

Genotype

• Definition: Set of alleles that an individual has for a character

• Characteristics: pair of alleles, written as two letters, determines genotype, etc.

• Examples: PP, Ee, tt• Non-examples: blue eyes, freckles, tall plant

Phenotype

• Definition: trait that results from an individual’s alleles

• Characteristics: physical appearance/trait, visible, determined by genotype

• Examples: blue eyes, freckles, tall plant• Non-examples: PP, Ee, tt

Dominant

• Definition: expressed when allele is present in a genotype/individual

• Characteristics: “wins” over other alleles, overshadows recessive allele, expressed, capital letter

• Examples: brown eyes, freckles, dimples• Non-examples: blue eyes, no freckles, no

dimples

Recessive

• Definition: only expressed when dominant allele is not present

• Characteristics: written as lower case letter, usually overshadowed, only expressed in homozygous condition

• Examples: blue eyes, no freckles, no dimples• Non-examples: brown eyes, freckles, dimples

Homozygous

• Definition: having two identical alleles for a characteristic

• Characteristics: SAME, two dominant or two recessive

• Examples: PP, tt• Non-examples: Bb

Heterozygous

• Definition: having two different alleles for a characteristic

• Characteristics: DIFFERENT, one dominant & one recessive

• Examples: Bb• Non-examples: PP, tt