Genetics THE SCIENCE OF HEREDITY Genetics Introduction 3

Genetics THE SCIENCE OF HEREDITY Genetics Introduction 3 min.

Gregor Mendel Was a priest in the 19 th century. Mendel was the father of genetics. ◦ Genetics is the study of heredity. Mendel used pea plants to cross pollinate. Bill Nye Discussing Mendel

Traits - Characteristics that an organism can pass off to its offspring through its genes. Examples of traits from pea plants: ◦ seed color ◦ height of plant ◦ Smooth pod, pinched pod ◦ pod color What are some examples of traits from humans?

Genetic Traits in Humans Genetic Traits Overview

Traits come from both parents We get ½ of our genes from one parent and the other ½ from the other parent.

Definitions Phenotype - An organism’s physical appearance or visible traits. What can be seen. (ex: freckles, curly hair) Genotype - An organisms genetic makeup or allele combination. What can not be seen. (ex: AA, Aa, aa) Allele – 2 forms of a gene, 1 from each parent and represented by lower case and capital letters. (ex: AA, Aa, aa) ◦ Think ALlele = ALphabet

Yeah, More Definitions Heterozygous - having two different alleles for a particular trait, one dominant and one recessive. (Aa) Homozygous – having the same 2 alleles for a particular trait, both dominant or both recessive. (AA or aa)

Other Genetic Traits Tongue curling

Other Genetic Traits LEFT HANDED OR RIGHT HANDED THUMB CROSSING

Other Genetic Traits VULCAN FINGERS OR NOT HITCHHIKER THUMB

Other Genetic Traits LONGER 2 ND TOE BENT LITTLE FINGER

Other Genetic Traits EYE COLOR FRECKLES

Earlobes

Hair on fingers? NO YES

Widows peak

Curly hair CURLY STRAIGHT

Chin CLEFT SMOOTH

Smile dimples SMILE DIMPLES NO SMILE DIMPLES