Genetics

Chapter 9-2

Parent Generation P1

• The 2 organisms that are used to reproduce

F1 generation

• The offspring - babies

F2 generation

• The babies of the F1 or the grandchildren of the P1

Punnett Square

• A way of organizing genetics so that scientist can determine the genotype of the offspring of 2 individuals

Monohybrid

• One cross because you are looking at only one trait

Dihybrid

• Two crosses - you are looking at 2 traits

Monohybrid Punnett Square Problems

• Height – tall is dominant to short

• Symbol for tall _______

• Symbol for short _____

• Phenotype: – Homozygous tall male X short female

• Genotype:– Male _____ X Female ______

P1 Punnett Square

– F1 genotype ratio

– F1 phenotype ratio

Monohybrid Punnett Square Problems

• Hairline: widows peak is dominant to no widows peak

• Symbol for widows peak _______• Symbol for no widows peak _____• Phenotype:• no widows peak male X widows peak

(heterozygous) female• Genotype:

– Male _____ X Female ______

F1 Punnett Square

– F1 genotype ratio

– F1 phenotype ratio

Monohybrid Punnett Square Problems

• Eyebrows: bushy eyebrows dominant to fine eyebrows

• Symbol for bushy _______• Symbol for fine _____• Phenotype: • fine eyebrows male X homozygous bushy

eyebrows female• Genotype:

– Male _____ X Female ______

F1 Punnett Square

– F1 genotype ratio

– F1 phenotype ratio