1/22/16 Starter: What determines the traits of an organism? 1/22/ Heredity and Genetics Application Notes Glue here when done Connection Ws Exit: Explain the difference between genotype and phenotype? Heredity and Genetics Practice: Watch Video and write 5 things you learn. /0/ /video_recap_of_chromosome_n umbers_by_amoeba_sisters.pdfhttp:// /0/ /video_recap_of_chromosome_n umbers_by_amoeba_sisters.pdf EQ: How does our individual genetic code influence who we are?

January 22, 2016 AGENDA B. 6 F Students will predict possible outcomes of various genetic combinations such as monohybrid crosses, dihybrid crosses and non-Mendelian inheritance while reading and writing by completing a ws. 1 Starter 2. Practice-Notes 3. Ws

Date Lecture/ Activity/ Lab Page 12/10 Say it With DNA Activity /14 Mutations /15 Mutations /5 Mutations and Pedigrees /6 Mutations and Pedigrees /7 Mutations and Poster /8 Mutations Writing /11 Pedigrees /12 Semester Exam Review /15 Gene Expression and Cell Differentiation /21 Mitosis and Meiosis /22 Heredity and Genetics Notes and Ws Table of Contents

Heredity and Genetics

Just think… “My parents have brown eyes, why are mine blue?” “My brother is tall. Why am I short?” “Why does my sister have blonde hair while mine is brown?”

Science can answer some of these questions… Heredity- the passing of characters from parents to offspring Genetics- the branch of biology that focuses on heredity

Gregor Mendel Father of Genetics

During his early years at the monastery, Mendel began studying and breeding mice. The bishop was not pleased.

Brother Gregor settled on bees...

and peas.

Why Peas? The garden pea is a good subject for several reasons. Peas… –Have characters that exist in clear forms, no intermediate forms –Have male and female reproductive parts enclosed on the same structure- mating can be controlled –Are small, grow easily, mature quickly, and produce many offspring (results can be quickly obtained and there are plenty of subjects to count)

Mendelian Theory of Heredity (the foundation of genetics) 1.For each inherited character, an individual has two copies- one from each parent 2. There are different versions of genes= alleles For example, the gene for flower color in peas can exist in a “purple” version or a “white” version

3. When two different alleles (versions) occur together, one of them may be completely expressed, while the other may have no observable effect on the organism’s appearance. Mendelian Theory of Heredity (the foundation of genetics) Dominant- the expressed form of the trait Recessive- the trait that is not expressed if a dominant allele is present Ex. P Ex. p

4.When gametes are formed, alleles for each gene separate- gametes only carry one allele for each characteristic During fertilization, gametes unite- each gamete contributes one allele to the offspring Mendelian Theory of Heredity (the foundation of genetics)

Genetic Laws The Law of Independent Assortment says that each gene pair is inherited independently of the gene pairs for all the other traits. The law of Dominance states that one factor of the gene pair is always predominate over the other factor.

Law of Segregation Law of Segregation-When the parents of an organism forms sex cells, the parent’s gene pairs segregate or separate. This means that one allele from each gene pair goes to each sex cell. When the sex cells from the male and female unite during fertilization, the individual receives a gene from each parent. Ee = parent genotypeee = parent genotypeEE = parent genotype Ee: makes 2 kinds of sex cells. ee: makes one kind of sex cell. EE: makes one kind of sex cell

Modern Terms Genotype- the genetic makeup of an organism (the set of alleles an individual has) Phenotype- the physical appearance of an organism Ex. PP or P p Ex. Purple

Modern Terms Homozygous- the two alleles present for a character are the same ex. PP or pp Heterozygous- the two alleles present for a character are different ex. P p

Heredity Inherited allele for purple P Inherited allele for purple P HOMOZYGOUS purple flower PP

Heredity Inherited allele for purple flower (P) Inherited allele for white flower ( p ) HETEROZYGOUS purple flower (P p )

Heredity Inherited allele for white flower ( p ) Inherited allele for white flower ( p ) HOMOZYGOUS white flower ( pp )

Predicting Heredity…

Probability The likelihood that a specific event will occur Probability = # of 1 kind of possible outcome Total number of possible outcomes Example: What is the probability that a tossed coin will be heads? ½ or 50%

Probability What is the probability that a couple will have four boys? ½ x ½ x ½ x ½ = 1/16 1/2

Monohybrid Cross: a cross that shows the possible offspring for one trait Example: Cross two heterozygote individuals: Aa x Aa Aa A a Genotypic Ratio: 1:2:1Phenotype: 3 white:1 brown A: White fur a: Brown fur AA Aa aa

Practice! Cross a HOMOZYGOUS dominant female with a HOMOZYGOUS recessive male using the same trait. AA a a Aa What is the genotypic ratio? What is the phenotypic ratio? 100% 4 white fur

Practice! Cross a HOMOZYGOUS dominant female with a HETEROZYGOUS male using the same trait. AA A a AA Aa What is the genotypic ratio? What is the phenotypic ratio? 2:2 or 50% 4 white fur

Test Cross Animal breeders and horticulturists often need to know if an organism is homozygous dominant or heterozygous for a character. However, it is impossible to tell simply by looking at an organism. They can use a test cross…

Test Cross An individual whose phenotype is dominant, but whose genotype is not know, is crossed with a homozygous recessive individual. (Based on the outcome of the cross, you can tell if the individual in question is homozygous dominant or heterozygous.)

Test Cross Is this purple flowering pea plant PP or P p ? Cross the unknown with a homozygous recessive individual. Set up a Punnett squares: Based on the actual outcome of the cross, determine the genotype of the unknown. P? X pp p p P p p p PP PpPp PpPp pp PpPp PpPp PpPp PpPp (If all offspring are purple, the unknown must have been PP)

1/22/16 Starter: What determines the traits of an organism? 1/22/ Heredity and Genetics Application Notes Glue here when done Connection Ws Exit: Explain the difference between genotype and phenotype? Heredity and Genetics Practice: Watch Video and write 5 things you learn. /0/ /video_recap_of_chromosome_n umbers_by_amoeba_sisters.pdfhttp:// /0/ /video_recap_of_chromosome_n umbers_by_amoeba_sisters.pdf EQ: How does our individual genetic code influence who we are?