Do Now Get out homework; turn in understanding cancer; Get out Codon Table Why is cancer more common in older people? The addition of one or more nucleotide base pairs into a DNA sequence is a(n) __________ mutation. How does this affect the protein made during protein synthesis?

Mendelian Genetics

Who is Gregor Mendel? Father of Genetics Raised in a poor farming family; joined the monastery to get an education Became the gardener of the monastery Noticed differences between plants; particularly pea plants Father of Genetics

Why peas? 1. Cheap

Why peas? 2. Peas grow very fast

3. Peas are easy to manipulate during reproduction Why peas? 3. Peas are easy to manipulate during reproduction

4. Peas have many traits to examine Why peas? 4. Peas have many traits to examine

Anatomy of a Flower Stamen = Male Pistil = Female Petal Stigma Anther: Pollen Style Filament Ovary: Eggs Stamen = Male Pistil = Female

Plant fertilizes it own eggs Self Pollination Plant fertilizes it own eggs

Pollen from one flower fertilizes the egg of another Cross Pollination Pollen from one flower fertilizes the egg of another

Mendel’s Experiment: P generation Parent Generation Mendel selected one pea trait to examine: Flower color

Pea Plant Cross Pollination Mendel cross pollinated a purple flower with a white flower

What do you think Mendel found What do you think Mendel found? What would be the result of crossing a purple flower with a white flower?

First Generation F1 generation: First generation Mendel decided to let the F1 generation to self-pollinate (fertilize own eggs) Mendel found that the resulting plants ALL had purple flowers

F2 generation: Second generation Mendel found that the resulting generation had purple and white flowers; in a 3 to 1 ratio

Conclusions: What does all of this mean? 1. Individuals inherit “factors” from parents

Conclusions: What does all of this mean? 2. These “factors” are passed from one generation to the next

Conclusions: What does all of this mean? 3. “Factors” may be passed along, but may not show up in offspring

Over 100 years later … Mendel explained: 1. The “factor” is a gene; part of DNA that codes for a trait; Flower color is a gene

34 years later … Mendel explained: 2. An allele is two different forms of a gene; Purple and White flowers

34 years later … Mendel explained: 3. On average, there are two alleles for each trait; one from mom and one from dad

Dominant and Recessive Alleles DOMINANT allele: Expressed trait; Capital letter, Always first

Dominant and Recessive Alleles recessive allele: Only expressed if paired with another recessive; Lowercase letter

What is genotype? Combination of alleles; allele letters that code for a trait; GENETIC makeup of gene

a. Homozygous Dominant: Two dominant alleles Types of Genotypes a. Homozygous Dominant: Two dominant alleles BB

b. Homozygous Recessive: Two recessive alleles Types of Genotypes b. Homozygous Recessive: Two recessive alleles bb

c. Heterozygous: One dominant and one recessive allele Types of Genotypes c. Heterozygous: One dominant and one recessive allele Bb

What is phenotype? Physical expression of trait; observable characteristic; physical appearance

Example B = Big nose and b = small nose What would be the phenotype for the following: BB Bb bb

Example B = Big nose and b = small nose What would be the genotype for the following: BB Bb bb

Baby Lab Heads: Dominant allele; N1, etc Tails: Recessive allele; N2, etc