1. Bell Work
Who is Gregor Mendel and what did he do?

2. Genetics with Punnett Squares
Biology – Lecture 47
Genetics with Punnett Squares

3. Genetics Vocabulary

4. Allele – different versions of the same gene
Because they are the same gene, they are given the same letter.
Example – height can either be tall or short

5. Genotype - the set of alleles for a given organism
Phenotype - the observable traits of the organism

6. Homozygous - Diploid organisms with two copies of the same allele of a given gene.
Both alleles will be capital letters or lower case letters.
Heterozygous - Diploid organisms with two different alleles of a given gene.
One allele will be capital, one allele will be lowercase.

7. Dominant allele – The allele in a heterozygous set of alleles that has dominant qualities in the phenotype. (capital letter)
Recessive allele – the allele in a heterozygous set of allele that has receding qualities and are not observed in the phenotype. (lower-case letter)

8. Incomplete dominance - expressing an intermediate phenotype
Co-dominance - expressing both alleles at once

9. Punnett Square - a diagram that is used to predict an outcome of a particular cross or breeding experiment.

10. Punnett Square Example
In rabbits, black fur is dominant over white fur. Show the cross of a heterozygous black male with a homozygous white female.
Phenotype:
Genotype:

11. Punnett Square Example
In humans, free-ear lobes are dominant to attached. Two parented that are both heterozygous free are expecting a child. What are the chances that the child will have free ear lobes of attached?
Phenotype:
Genotype:

12. Punnett Square Practice
Wrinkled seed are recessive to smooth seeds. Show a plant that always produces wrinkled seeds crossed with a heterozygous smooth seeds producing plant.
Phenotype:
Genotype:

13. Punnett Square Practice
Wrinkled seed are recessive to smooth seeds. Show a heterozygous smooth plant crossed with another heterozygous smooth seed producing plant.
Phenotype:
Genotype:

14. Punnett Square Practice
Blue eyes are dominant to red eyes in rabbits. Show a heterozygous blue-eyed rabbit crossed with a red-eyed rabbit.
Phenotype:
Genotype:

15. Punnett Square Practice
In fruit flies, red eyes are dominant over white eyes. Show a cross between two white-eye fruit flies.
Phenotype:
Genotype:

16. Punnett Square Practice
Curly hair is recessive, and straight hair is dominant. A woman with curly hair marries a man who is homozygous dominant for straight hair. Predict the outcomes for their children.
Phenotype:
Genotype:

17. Punnett Square Practice
Black hair is homozygous dominant. Brown hair is heterozygous. Blonde hair is homozygous recessive. (This is an example of incomplete dominance.) A woman with brown hair marries a man with brown hair. What are the possible outcomes for their kids?
Phenotype:
Genotype:

18. Punnett Square Practice
Freckles are recessive. No freckles are dominant. Mom= heterozygous Dad=homozygous recessive. What are the possible outcomes for kids?
Phenotype:
Genotype:

19. Pop Quiz

20. Pop Quiz - Punnett Square
Tall is dominant over short in pea plants. Show the cross of a homozygous short plant is crossed with a homozygous tall plant.
Phenotype:
Genotype: