2/22/2016, 10.1 – Intro. To genetics LT: Today I will… – Differentiate between a gene and trait – Define some basic genetics vocabulary ET: Read the chapter mystery on pg Write down the question that is to be investigated as we go through the chapter.

Basic vocabulary to help in our study of genetics Genetics Fertilization Trait Hybrid Gene Allele Principle of dominance Segregation gamete

Vocabulary cont… Gametes: These are sex cells – Ex. Animals have sperm and egg – Ex. Plants have pollen and ovum Fertilization: in sexual reproduction, this is the joining of gametes – Ex. Sperm and egg form a cell that develops into an embryo

Vocabulary Genetics: the study of heredity – the passing of genetic information from one generation to the next Trait: the physical expression of a gene, basically a characteristic Gene: the actual information in the DNA that determines traits. This is what is passes from generation to generation Allele: Different forms of a trait – The trait is height – The different alleles for height could be short or tall

Traits VS. Alleles The trait - eye color – Alleles (forms): blue, brown, green The trait - thumb shape – Alleles: bent or straight The trait - hair line – Alleles: widows peak or straight

Vocabulary continued… Segregation: When homologous pairs of chromosomes (one moms and one dads) separate to make gametes (haploid cells) Principle of Dominance: some alleles are dominant over others

Lets look at some of these traits! Read through the “Quick lab” on pg. 311 Make the data table in your notebook Make your prediction according to step 2 Figure out your features Survey your friends!

2/23/ Gregor Mendel Learning Targets: – Describe how Mendel studied inheritance in peas – Summarize Mendel’s conclusions about inheritance Entry Task: – Trait: fur pattern – Alleles: ???? – Pick a trait and list the possible alleles for that trait

Gregor Mendel 1822 Who: An Austrian monk What: developed an explanation for the mechanism of evolution

What Mendel did… PParental F 1 Generation F 2 Generation

Genotype VS. Phenotype Genotype Homozygous – an organisms has two identical alleles, like “TT.” Both parents gave a tall allele – Homozygous dominant – Homozygous recessive Heterozygous – an organisms has two different alleles, like “Tt.” Parents gave different forms of the height gene Phenotype: what form of the trait is expressed – what they look like! Tall Short Blue eyes etc… What every form of trait you see in that individual

Lets practice! For each set of alleles, write the genotype and phenotype. Straight hair is dominant over curly – SS – Ss – ss Freckles recessive to no-freckles – FF – Ff – ff Brown fur is dominant over white – BB – Bb – bb

11.2 – Genotypes and Phenotypes ET: Choose letters and write the alleles for the given genotype – Brown eyes is dominant over blue eye Homozygous dominant Heterozygous Homozygous recessive – Widows peak is dominant over straight hair line Homozygous dominant Heterozygous Homozygous recessive – Attached ear lobes is recessive to unattached Homozygous dominant Heterozygous Homozygous recessive

Mendel’s Conclusions Inheritance is determined by factors that are passed from one generation to the next, genes. Some forms of a trait (alleles) are more dominant than others, the principle of dominance

Biology – 2/24/2016 LT: Today I will… – Make predictions about patterns of inheritance – Use mathematical methods for solving genetics problems (Punnett square) ET: Write the genotype for an individual who has attached ear lobes, has a widows peak, and hairy fingers – eeWWFF – eeWwFw

Punnett Squares We will cross two homozygous parents TT – homozygous dominant tt – homozygous recessive TT t t

2/25/2016: 11.2/11.3 – Probability and Patterns of Inheritance LT: Today I will… – Explain the principle of independent assortment – Use Mendel’s principles to solve punnett square problems ET: What are the possible allele combination in the following individuals gametes – Genotype is TTRRGG – Genotype is ttrrgg – Genotype is TtRrGg

Lets practice making gametes! If the genotype is… 1.Bbyy 2.bbYY 3.BBYy 4.HHJJII 5.Hhjjii 6.HhJjIi Possible gametes are… By by bY BY By HJI Hji hji HJI HjI Hji HJi hJI hji hJi hjI

Continued… Sex linked traits – some inherited traits are located on the chromosomes that determine gender, the X or Y. Females have two X chromosomes: XX genotype Males have one of each: XY genotype – EX. Hemophilia is an X-linked recessive disorder. This means… If you’re a make, XY, and you inherit a recessive allele it will show up because you do not have another X chromosome with a normal dominant allele to over power it.

The Two-Factor Cross: 2 traits P generation: RRYY homozygous dominant for round yellow peas x rryy homozygous recessive for wrinkled green peas RRYY Parent’s Gametes – rryy Parent’s Gametes - RY ry

Lets cross 2 F1 generation plants! All the possible combos. RYRyrYry RYRRYYRRYyRrYYRrYy RyRRYyRRyyRrYyRryy rYRrYYRrYyrrYYrrYy ryRrYyRryyrrYyrryy

Incomplete Dominance = A blending of both alleles – Ex. The allele for red petals is not completely dominant over the allele for white petals so the offspring has pink petals Other forms of Inheritance

Continued… Co-dominance = Both traits will show up. They are not blended together, you actually see both – Ex. The allele for black feathers is co-dominant with the allele for white feathers so the bird is black and white spotted

Biology 2/29/2016 – Meiosis Simulation Genegames/snurfle_meiosis_and_genetics.ht ml Genegames/snurfle_meiosis_and_genetics.ht ml

Independent Assortment Genes for different traits can segregate independently during the formation of gametes (meiosis)

Crossing Over

Lets Model this Process! Get your bag of chromosomes And pull out one set of chromosomes

Polygenic Traits Traits controlled by two or more genes: eye and skin color. So there are several different combinations possible *Incomplete dominance – In a heterozygote there is a blending of the two traits ex. Red and white produce pink *Co-dominance – In a heterozygote both traits are visible ex. Black and white speckled chickens