HEREDITY

Gregor Mendel Mendel discovered the principles of heredity while studying pea plants.

Mendel labeled all parental plants as P1 and the offspring as F1

HEREDITY IS THE TRANSMISSION OF CHARACTERISTICS FROM PARENTS TO OFFSPRING.

GENETICS THE FIELD OF BIOLOGY THAT INVESTIGATES HOW CHARACTERISTICS ARE TRANSMITTED FROM PARENTS TO OFFSPRING.

DOMINANT TRAIT One of the traits is controlled by or is over-ridden by the other factor. A characteristic that prevails.

RECESSIVE TRAIT This trait seems to fade into the background. Recede – to go away or back off

To tell if a trait is dominant or recessive, compare the traits of P1 and F1 generations

Abby Glover Brad Pitt

Dion Hill Ashley Tisdale

Ashley Seavers Johnny Depp

GENES A segment of a chromosome that determines a particular trait. Each parent gives one set of genes to the offspring. The offspring that have two forms of the same gene for every characteristic.

ALLELES Different forms of the same gene Dominant alleles are shown with a capital letter, and recessive alleles are always shown with a lowercase letter. Ex. T – tall t - short

HOMOZYGOUS When two alleles for a trait are identical Ex. T T

HETEROZYGOUS When two alleles for a trait are not identical Ex. T t

PUNNETT SQUARE A diagram that summarizes Mendel’s calculations about the probability of different offspring being produced.

PHENOTYPE An organisms appearance or other detectable characteristic (physical appearance) EX. Skin color, eye color, hair color

GENOTYPE The entire genetic makeup of an organism Describes the traits you get

Chromosomes are made from a chemical compound called deoxyribonucleic acid, DNA. This is what the genes that are passed from one generation to the next are made of.

The structure of DNA is a double helix.

A double helix is like a ladder that is twisted to form a spiral. The sides are made of sugars and phosphates and the steps are made of bases.

The bases are known as: Adenine Thymine Guanine Cytosine

The bases match up in the following ways: Adenine – Thymine Guanine - Cytosine

GENETIC ENGINEERING The manipulation of genes by humans. Ex. Cure diseases treat genetic disorders manufacture medicines