1. Introduction to Genetics The study of heredity: how genetic factors are passed down from one generation to the next

2. His experiments with pea plants laid the foundations of the science of genetics His experiments with pea plants laid the foundations of the science of genetics

3. Male part: produces pollen Female part: where fertilized egg will become a seed Female part: where fertilized egg will become a seed

4. Mendel cross-pollinated a purple plant with a white plant

5. He found all the offspring produced purple flowers. What happened to the white flower trait?

6. P generation: Parental generation; always True-breeding, or “pure-bred” F1 generation: First Filial Generation; offspring of P gen, always hybrids

7. PPpp pPppPp pPppPp pPppPp pp x pPppPp

8. Mendel made the F2 generation by crossing plants from F1 together. He found 3 purple flowers for every 1 white flower.

9. Mendel found the same pattern with many other pea plant traits.

10. Mendel’s Law of Segregation explains how genes are passed to the next generation. Alleles are segregated into separate egg cells and sperm cells. Each reproductive cell will pass on ONE of the alleles. Alleles are segregated into separate egg cells and sperm cells. Each reproductive cell will pass on ONE of the alleles. New pairs of genes are created for the next generation during fertilization New pairs of genes are created for the next generation during fertilization

11. Because of sexual reproduction, you are a product of your mom’s genes and your dad’s genes

12. Each chromosome contains thousands of genes. Each gene is the DNA code for making a specific protein. The proteins give you your trait.

13. The alternate forms of genes are called alleles. You always get two alleles for a trait.

14. The combination of alleles for a specific trait are called the genotype. This is represented by two letters. Pp

15. If both alleles are the same, then they are homozygous. If they are different, they are called heterozygous. http://www.abpischools.org.uk/page/modules/genome/dna2.cfm

16. Sometimes, one allele is expressed as a trait and the other isn’t. The dominant allele is expressed and the recessive allele is not.

17. The observable trait is called the phenotype. The phenotype is a result of the genotype. P p

18. P pppp Offspring Genotypes If you know your genotype for a specific trait, you can predict the traits of your offspring! Use a Punnett Square.

19. How to Solve a genetics problem 1. Read the problem 2. Take notes: _____=Gray body _____=Gray body _____=black body _____=black body 3. Box the parent descriptions: Heterozygous gray body Heterozygous gray body Black body Black body 4. Determine the genotypes of the parents (_, _) 5. Fill in the Punnett square and solve

20. G g gggg Heterozygous X black Gray (Gg) (gg) Genotype probabilities : Gg=50%, gg=50% Phenotype probabilities : gray bodies=50%, black bodies=50%

21. Situation: A client wants to buy pure bred black puppies from your dog. This means your dog must be pure black to make pure bred puppies. How can you tell if your black lab is BB or Bb? How can you tell if your black lab is BB or Bb?

22. Conduct a test cross and breed it with a brown lab (homozygous recessive) to find out and examine the traits of the puppies. These puppies are not for sale, but give you important information about your dog.

23. Practice Makes Perfect Now practice using the terminology and Punnett Squares to determine possible traits Now practice using the terminology and Punnett Squares to determine possible traits