Taste Testing ●Place the PTC paper in your mouth ●Describe to those around you what you experience

Taste Sodium Benzoate and Thiourea ●Do you taste all of them? None of them? Some of them?

How Do You Taste Things? ●Why can some people taste them, and some people can’t? ●**Think back to previous units

How Do You Taste Things?

Why The Different Reactions? The ability to taste PTC is caused by a single gene. you have two copies of this gene, either taster or a non-taster. Explain why there are three tiers of tasting PTC

Is PTC Tasting “good”? Why might people from some areas benefit from an ability to be sensitive to bitter?

Is PTC Tasting “bad”? Why might people from some areas benefit from NOT tasting bitterness with PTC?

Does your family share your tastes? Do you have similar feelings about broccoli, cabbage and dark chocolate?

Bitter Taste is Associated with Vegetables like Broccoli Did anyone taste PTC strongly but like broccoli? Propose an explanation?

Inheritance and Mendelian Genetics

Vocab words ●Phenotype: the outward expression of the genes (what the organism looks like) ●Genotype: the genetic make-up of a cell of an organism (the genes it has) ●Gene: Gene is a molecular unit of heredity that is found on the chromosome. ●Allele: version of a gene. Each organism has two alleles of each gene ●Heredity: is the passing of phenotypic traits from parents to their offspring, either through asexual reproduction or sexual reproduction.

Example ●Individual can be AABb ●This person has two genes, A and B ●For each gene, the individual has two alleles (A and A or B and b) Inherited from mom Inherited from dad

Gregor Mendel ●German Scientist who grew pea plants ●is heralded as the founder of modern Genetics ●Established many rules of heredity

Gregor Mendel’s Findings ●Two pea plants mated, some traits are passed down to the offspring more readily than others. ●Deemed the traits that showed up more often as Dominant, and the ones that showed up less often as Recessive.

Alleles ●Use capital letters to describe dominant alleles (AA,BB, CC) ●use lower case letters to describe recessive alleles (aa, bb) ●two copies of either dominant of recessive allele (AA or aa) = homozygous ●two different copies (Aa) = heterozygous, but still showed the dominant phenotype

Complete Dominance ●The dominant allele is expressed over the recessive allele if you have both ●E.g. TT and Tt are both tall, only tt is short TT or Tt RR or Rr tt YY or Yy rryy

Punnett Square Diagram that is shows the possible traits two parents can pass on, and the resulting kids they can have Aa Parents Offspring What is the phenotype of the offspring?

Examples What are the phenotypes and genotypes of the F1 and F2 generations? F2= mating between two F1 offspring

Homework The worksheet is to be finished for HW if not completed in class You will investigate some other inheritance patterns besides complete dominance We will whiteboard the problems tomorrow in class