Do Now #1 5/8/18 What do all of these have in common?

Genetics and Inheritance Chapter 11

DNA  gene controls one specific trait. Gene = one section of DNA that (Examples: Hairline gene, earlobe gene, etc.)

DNA  gene  chromosome

How are these traits passed from one generation to the next? Every living things inherits traits, or characteristics, from its parents. How are these traits passed from one generation to the next? The answer lies in the study of genetics.

Essential Question: Mendelian Genetics "How can two brown fur rabbits have a white fur baby?"

Genetics Definition = The branch of biology that studies heredity. (Heredity = biological inheritance)

Gregor Mendel “Father of Genetics” ~Austrian monk ~In charge of the monastery garden ~Experimented with pea plants Gregor Mendel    1822-1884  

Mendel observed seven traits that are easily recognized and apparently only occur in one of two forms:

Mendel knew an important fact of his pea plants: The flowers have both male and female reproductive parts.

Fertilization of a plant’s egg cells by the pollen of another plant = Pollination Pea plants contain both male and female parts, so they can produce seeds by… SELF-POLLINATION Fertilization of a plant’s egg cells by the pollen of another plant = CROSS-POLLINATION

Terminology: Allele – alternative form of a GENE 1. Gene- a section of DNA that controls a specific trait Allele – alternative form of a GENE Trait—a characteristic of a species determined by specific genes

Dominant gene—the presence of this type of gene will mask/hide the other gene Recessive gene—this gene is hidden by the other gene unless there are two copies of the recessive form.

Video from: http://ed. ted

By breeding many plants over and over, he found that "statistically" Results By breeding many plants over and over, he found that "statistically" certain traits appeared with a certain probability

Mendel’s Results and Conclusions: Biological characteristics are determined by genes. (Genes are passed from parents to their offspring.)

Mendel’s Results and Conclusions: Some forms (alleles) of a gene may be dominant and others may be recessive.

Mendel’s Results and Conclusions: In most sexually reproducing organisms, each adult has two copies of each gene—one from each parent. These genes are segregated/separated from each other when gametes are formed. (Law of Segregation)

Mendel’s Results and Conclusions: The alleles for different genes usually segregate independently of one another. (Law of Independent Assortment)

Heredity WebQuest http://www.dnaftb.org/1/

Do Now #2 11/29/16 Use figure 11-4 on page 265 to answer the following questions Why are none of the F1 generation short? Why do the F1 plants have an allele for shortness? What proportion (ratio) of the F2 plants had a trait controlled by a dominant allele?

Terminology continued: 6. HYBRID –offspring of parents with different traits 7. Homozygous - both pairs of genes for a specific trait are the same 8. Heterozygous - both pairs of genes are different

Terminology Con’t… 9. Genotype – the genetic makeup of an organism (ie. AA, Aa, aa) 10. Phenotype – the physical appearance of an organism (ie. Hair color, eye color, etc.)

Monohybrid Crosses. A cross between individuals that Monohybrid Crosses A cross between individuals that involves ONE pair of contrasting traits

Punnett Squares!!! = tool used to determine the probability of offspring of a cross between two parents

Punnett Squares B b MonoHybrid Cross = DOMINANT (capital letter) Can be used to predict & compare the genetic variations that will result from a cross = DOMINANT (capital letter) = DOMINANT B MonoHybrid Cross = recessive (lower case) = recessive b

Punnett Squares Squares Punnett Can be used to predict & compare the genetic variations that will result from a cross = DOMINANT = DOMINANT (capital letter) HOMOzygous = organisms that have 2 IDENTICAL alleles for the same trait B = recessive (lower case) = recessive HETEROzygous = organisms that have 2 DIFFERENT alleles for the same trait b

Do Now #3 11/30/16 What is a genotype? How do we write a genotype? What is phenotype? Give an example. What is the difference between homozygous and heterozygous genes?

The likely hood that a particular event will occur 12/1/2018 3:52 AM Probability – Penny Genetics The likely hood that a particular event will occur T = Tails t = Heads Squares Punnett Segregation © 2007 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries. The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

Do Now #4 12/1/16 Trait for Tongue Rolling R = Dominant = CAN roll tongue r = Recessive = can NOT roll tongue Cross Parent 1 (Rr) with Parent 2 (rr) and answer the following: What is the genotype of each parent? Write the genotype for each offspring. What is the phenotype for each offspring? What percent of the offspring have a heterozygous genotype?

Do Now #5 12/2/16 Get a Genetics Review Sheet from the front desk. Try to complete it WITHOUT notes first. Compare answers with a neighbor.

Test Cross To determine the GENOTYPE of an organism expressing the dominant phenotype. Testcross= a mating between an individual with an unknown genotype and an individual that is HOMOZYGOS RECESSIVE. –> Look at offspring to determine parent genotype Example: Labrador Retriever B= black fur b= chocolate brown fur Black lab X chocolate lab B___ X bb

Test Cross Example In humans, long eyelashes is (E) is dominant over short eyelashes (e). A man with long eyelashes marries a woman with short eyelashes and they have three children, two of whom have long eyelashes and one of whom has short eyelashes. Draw the Punnett squares that illustrates this marriage. What is the man’s genotype? What are the genotypes of the children?

Dihybrid Crosses. A cross between. individuals that Dihybrid Crosses A cross between individuals that involves TWO pairs of contrasting traits

Parents: _GGBB______ x ____ggRR_____ #15 Parents: _GGBB______ x ____ggRR_____ GB GB GB GB GgBR gR gR gR gR

Parents: _GgRB______ x ____GgRB_____ #16 Parents: _GgRB______ x ____GgRB_____ GB gR gB GR GGRR GGRB GgRR GgRB GGBB GgBB ggRR ggRB ggBB GR GB gR gB

Parents: _____________ x _____________

Patterns of inheritance

One allele can completely hide the other (Mendel traits) 1. Complete Dominance One allele can completely hide the other (Mendel traits)

Flower Color in Snapdragon 2. Incomplete Dominance Flower Color in Snapdragon =both alleles influence the phenotype (blending)

Incomplete dominance in humans

Complete Pedigree Practice Sheet from front table Do Now #9 12/8/16 Complete Pedigree Practice Sheet from front table

(both traits are seen—spotting) Codominance neither alleles totally masks the other (both traits are seen—spotting) RR = red hair rr = white hair Rr = roan (red AND white hairs present)

Codominance and multiple alleles

Most common blood type

Have class notes and handouts out and ready for Quiz Do Now #10 12/9/16 Have class notes and handouts out and ready for Quiz

One trait is controlled by multiple genes 4. Polygenetic One trait is controlled by multiple genes Examples: Height, skin color

5. Pleiotropy One gene affects multiple traits --In humans these usually present themselves with disease. Example: sickle cell disease