1. 11-1
Gregor Mendel
What he did

2. Genetics Genetics = the scientific study of heredity
Mendel understood the basic idea of fertilization = when the male and female reproductive cells join to make new cells, and grow to become new organisms.

3. Who is Gregor Mendel? Known as the “Father of Genetics”
Worked with pea plants
Looked at traits and how they are passed on

4. Genes and dominance
Trait = a specific characteristic (tall, short, green, yellow)
Hybrid = having parents with different traits
Genes = The chemical factors that determine traits, found in DNA
Allele = The different forms of a gene
Being tall or short

5. What Mendel Did Mendel started with two pure strain plants
(he knew exact parent traits)
Mendel crossed two plants with pure opposite traits, one pure tall plant with one pure short plant
Only one of the traits appeared in the next generation, all the offspring were tall
Mendel called this the F1 generation

6. Mendel concluded that Tall is the dominant allele
Short is the recessive allele
Dominant trait is the trait that is seen
Recessive trait is the trait that is not seen (hidden)

7. Law of Dominance
States that some alleles are dominant and others are recessive

9. Explaining the F1 Cross
During gamete formation, alleles segregate from each other so each gamete carries only a single copy of each gene
Gamete = sex cell
Segregation = separation of the alleles

11. Genetics and Probability
11-2
Probability is the likelihood of a particular event happening
Flipping a coin – what is the chance of getting a head? Tail?
Probability can be used to predict the outcomes of genetic crosses

12. Punnett Squares
Punnett Square = a diagram used to show the gene combinations that might result from a genetic cross

13. Tall (TT) x Short (tt)

14. Tall (TT) x Short (tt)

15. Tall (TT) x Short (tt)

16. Homozygous = when an organism has two identical genes
Example TT or tt
Heterozygous = having two different genes
Example Tt
Phenotype = physical characteristics; what is seen
Example = tall or short
Genotype = the genetic make up; what the genes are
Example = TT, tt and Tt

17. Probability Predicts Averages
Probabilities predict the average outcome of a large number of events
Probability cannot predict the precise or actual outcomes