Transcript Genetic Traits

Genetics
THE SCIENCE OF HEREDITY
Genetics Introduction 3 min.
Gregor Mendel
Was a priest in the 19th century.
Mendel was the father of genetics.
◦ Genetics is the study of heredity.
Mendel used pea plants to cross pollinate.
Bill Nye Discussing Mendel
Mendel’s Work
Some of Mendel’s questions were:
Why are some pea plants short while others are tall?
Why did some plants produce green seeds and other plants produced
yellow seeds?
These characteristics that Mendel was describing are called traits.
Traits
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 2ND 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
Please
turn to
page 116
in the
green
science
book.