Introduction to Genetics

Analyzing Inheritance

Chapter 6

Section 3

Probability

• The likelihood of an outcome randomly occurring

• Flipping a coin– Heads 4x’s in a row

• ½ x ½ x ½ x ½ = 1/16

Homozygous Dominate & Homozygous Recessive Cross

• 100% Bb

Genotype & Phenotype

• Genotype– The genes an

organism carries

• Phenotype– The traits an organism

expresses

Hybrid Cross

• 1:2:1 offspring

Earlobes

• Free is Dominant• Attached is recessive

Finger Digit Hair

• Hair is dominant• No hair is recessive

Widow’s Peak

Roll Tongue

• Tongue Roll is Dominant

• Non-Roll is Recessive

Thumb Flexibility

Pinky

• Sraight– Recessive

• Bent– Dominant

2nd toe longer than 1st

• Longer 2nd toe– Dominant

• Shorter 2nd toe– recessive

Color Blindness

• Sex Linked– More common in males– Recessive

Freckles

• Dominant • Recessive

Dimples

• Dominant

Cleft Chin

• Cleft– Dominant