HEREDITY

& GENETICS

Heredity

� The study of the passing on of traits from

parents to kids.

� Learn how and why physical and behavioral

characteristics are passed on to from parents to

offspring.

Trait

� A person’s behavioral and physical

characteristics.

� Example: brown hair, blue eyes, etc.

� Can also be behavioral such as personality.

Gene

� A specific trait.

� Example: hair color is a trait whereas a gene is the

specific color such as brown.

� Trait = Hair Color / Gene = Brown, Blonde, Red

� Trait = Height / Gene = Tall or Short

� Trait = Personality / Gene = Outgoing, Quiet

Offspring

� A child in relation to its parents.

Phenotype

� A person’s physical characteristics.

� Example: Tall or short, Blonde or brunette, etc.

Gg =

Genotype

� An organisms genetic code represented by

letters.

� Example: AA, Aa or aa

Gg GG

Allele

� The different forms of a trait that a gene

might have.

� Example: GG or Gg

Dominant

� A trait that covers up another trait.

� Example: An uppercase “A”.

Recessive

� A trait that gets covered up by an dominant

trait.

� Example: An lower case “a”.

Homozygous

� Having two identical alleles for a trait.

� Example: AA or aa

Heterozygous

� Having two different alleles for a trait.

� Example: Aa

Purebred

� Both alleles are the same. The same genetic

code is passed on by both parents.

� Example: AA

Hybrid

� The two alleles for a trait are different. The

genetic code that is passed on by each parent

is different.

� Example: Aa

Chromosome

� A threadlike strand that contains DNA and is

found in the nucleus 0f each cell. Humans

have 23 unique chromosomes.

� Example:

DNA

� Found in the chromosomes and transmits

genetic information.

� Example: