Bell Work Where do organisms get their unique

Bell Work • Where do organisms get their unique characteristics? Assignments: Gregor Medel & Punnett Square Notes/Practice Stamp: Gregor Medel questions/ vocabulary)

Bell Work • Why did Mendel use pea plants for his experiments? • Finish Vocabulary Organize Notebook Assignments: • Mendel Notes & Monohybrid Crosses

• Pea plant are easy to use, and they grow fast so you don’t have to wait a lot of time to see the plants in their maturity. • Each pea in the pod is an offspring, which means a lot of offspring’s in each plant. • You can cross or self-pollination them, by yourself so you can have more control over the plants. If he had chosen animals he could not self-reproduce them, and they had more traits that will difficult it.

GENETIC TERMS • Gene: a sequence of DNA that encodes for a certain trait • Allele: one of two (or more) alternative forms of a gene (a single letter) • Dominant Allele: an allele that dictates the expression of a trait (capital letter, ex: A) • Recessive Allele: an allele whose trait is masked by the presence of a dominant allele (lower case letter, ex: a)

TERMS • Genotype: genetic make-up of an organism (letter combination) • Phenotype: physical appearance of an organism (its outward appearance) • Homozygous: both alleles in a gene pair code for the same trait (ex: AA or aa) • Heterozygous: the two alleles in a gene pair that do not code for the same trait (ex: Aa)

TERMS • Sex Chromosome: the chromosome that determines the sex of an organism (the X and Y chromosome) • Autosome: any chromosome that is not a sex chromosome • Punnett Square: a chart which shows all possible gene combinations in a cross of parents • Monohybrid cross: a cross between two individuals for one trait (ex: Aa x Aa) • Dihybrid cross: crossing two different characteristics at the same time (Aa. Bb x Aa. Bb)

TERMS • Genotypic Ratio: the number of times each genotype appears in the offspring. Written from most dominant trait to the recessive. • Phenotypic Ratio: the number of times each phenotype appears in the offspring. Written from the dominant trait to the recessive.

GENETICS THE FIELD OF BIOLOGY DEVOTED TO UNDERSTANDING HOW CHARACTERISTICS ARE PASSED FROM PARENT TO OFFSPRING.

GREGOR MENDEL (1823 – 1884) • AUSTRIAN MONK WHO STUDIED MATH & STATISTICS. • HE BECAME KNOWN AS THE “FATHER OF GENETICS”.

Write the genotype • Homozygous dominant • Heterozygous • Homozygous recessive

Now add the phenotypes

• What is the difference between a purebred and a hybrid? Circle the purebred genotype(s).

It was very important to Mendel’s experiments that the P generation plants were purebred of contrasting traits. X P generation X F 1 generation F 2 generation

On your whiteboards, Draw a diagram like the diagram on your notes page, that identifies which plants had green pods and which plants had yellow pods for each generation. Green is dominant to yellow. Look on page 311 as a resource. P generation F 1 generation F 2 generation

MENDEL’S RESULTS • AFTER CROSSING A PURE GREEN PODDED PLANT WITH A PURE YELLOW ALL OF THE OFFSPRING WERE GREEN. • AFTER THESE OFFSPRING (F 1) WERE CROSSED THE RESULTING OFFSPRING (F 2) CAME OUT TO A 3 TO 1 RATIO FOR GREEN PODDED PLANTS.

Punnett Squares A Punnett square is a chart which shows all possible gene combinations in a cross of parents. – Horizontally across the top of the chart are the possible gametes of one parent. – Vertically down the side of the chart are the possible gametes of the other parent. – In the boxes of the chart are the possible T T genotypes of the offspring. TT x tt t t Tt Tt

Instead of just listing the phenotypes, list the genotypes for each plant. • Show the Punnett square for the P generation and the F 1 generation crosses

MENDEL’S LAWS • LAW OF SEGREGATION - -Reproductive cells only receive one factor (gene) of each pair.

LAW OF INDEPENDENT ASSORTMENT: The factors (genes) for different characteristics are not connected (seed shape has no effect on seed color)

P= purple flower p= white flower Monohybrid Cross: GENOTYPIC RATIO: 1: 2: 1 PP: Pp: p p dominant: Homozygous Heterozygous: Homozygous recessive PHENOTYPIC RATIO: 3: 1 Purple: Whit e Dominant: Recess ive two heterozygous individuals Pp P x Pp p P PP Pp pp

Monohybrid Practice

Bell Work: Get Punnett Square Practice out for stam B= brown eyes b= blue The eyesgenotypic ratio is: 0: 2: 2 The phenotypic ratio is: 2: 2 1: 1 Bb x bb

HOW DID MENDEL FIGURE OUT IF THE PURPLE FLOWERING PLANTS WERE HOMOZYGOUS DOMINANT OR HETEROZYGOUS FOR THE p GENERATION?

The Testcross • A genetic procedure devised by Mendel to determine an individual’s actual genetic composition • A purple-flowered plant can be homozygous dominant (PP) or heterozygous (Pp) – One cannot tell by simply looking at the phenotype – One can tell from the results of a cross between the test plant and a homozygous recessive (pp) plant

How Mendel used the testcross to detect heterozygotes.

Mystery Black Guinea Pig • Black fur color is dominant over white fur color. • If I hand you a black guinea pig, could you tell me the phenotype? • Could you tell me the genotype? • Show me what you would need to do to figure out the genotype and show the Punnett squares.

In pea plants, yellow peas are dominant over green peas. Predict the genotypic and phenotypic outcome of a cross between a plant heterozygous for yellow peas and a plant homozygous for green peas. Genotypic Ratio: Phenotypic Ratio: * Have Penny Lab out!!

What is the purpose of a Punnett square?

Bell Work • Why would a test cross be needed? What results would you be looking for to help you? Assignments: -Dihybrid Crosses -Inventory of Your Traits (Have out on desk)

LAW OF INDEPENDENT ASSORTMENT: The factors (genes) for different characteristics are not connected (seed shape has no effect on seed color)

• Can genes be linked if they are found on different chromosomes?

Pp. Qq x Pp. Qq Crossing 2 different characteristi cs at the same time.

Dihybrid Cross E= Brown eyes e= Blue eyes Cross H= Brown hair h= Blonde hair Parent 1: Heterozygous for Brown eyes and Homozygous dominant for brown hair Parent 2: Heterozygous for Brown eyes and heterozygous for brown hair Step 1: Figure out what the genotypes are for each parent

Dihybrid Cross E= Brown eyes e= Blue eyes H= Brown hair h= Blonde hair Ee. HH & Ee. Hh Step 2: Figure out the possible genotype combination for each parent. Parent 1: _____ Parent 2: _____ Step 3: Add gamete combinations to Punnett Square

Dihybrid Cross EH EH EH Ee. HH & Ee. Hh H Eh EEH E= Brown h e= Blue eyes e. H Ee. H eyes H H= Brown hair eh Ee. H h= Blonde h EEH H EEH h Ee. H H Ee. H h Cross e. H Ee. H H H Ee. H h h ee. H H H ee. Hh

Step 4: Find the phenotypic ratio (first list the 4 possible phenotypes from dominant to recessive and count how many individuals express each combination) Phenotype (dominant to recessive) % # with phenotype Ratio:

AND THE Needs an E and H PHENOTYPIC Needs an E and 0/16 RATIO IS…. hh What does an offspring need to have brown eyes and brown hair? What is the chance of having that? 12/16 What does an offspring need to have brown eyes and blond hair? What is the chance of having that? What does an offspring need to have blue eyes and brown hair? What is the chance. Needs of having that? an ee 4/16 and H What does an offspring need to have blue eyes and blond hair? What is the chance of having that? 12: 0: 4: 0 Needs an ee and 0/1

Rr. Yy x Rr. Yy Phenotypic Ratio

Bell Work Turn In Labs/ Stamp Dihybrid Crosses • If two genes are inherited together 75% of the time, what does that tell you about their location on the chromosome? Assignments: -Dihybrid practice (start after bell work) -Penny Genetics (Expected versus Observed ratios) -Gene Doctor Video Guide

Review Learning Goal Sheet

Let’s review Mendel’s experiment

Penny Genetics Comparing Expected Ratios to Observed Ratios

Bell Work: Mendel saw complete dominance in pea plants, which is where one dominant allele completely masks a recessive allele. What are your best guesses about what type of pattern of inheritance you would see in traits that show incomplete dominance and codominance? Assignments: Incomplete and Codominance **Turn in bell work from last week.

Some Traits Don’t Show Mendelian Inheritance • Mendelian segregation of alleles can be disguised by a variety of factors – Incomplete dominance – Codominance – Sex-linked – Environmental effects – Continuous variation – Epistasis

DIFFERENT TYPES OF DOMINANCE • COMPLETE DOMINANCE- a heterozygous & a homozygous dominant organism are the same phenotypically. –i. e BB=Bb

COMPLETE DOMINANCE B=brown eyes b=blue eyes All offspring will be…? Bb BB x bb B B b Bb Bb

• INCOMPLETE DOMINANCE- 2 or more alleles influence the phenotype resulting in a phenotype intermediate of the dominant and the recessive trait. + =

Incomplete Dominance Rule: Use the same letter for dominant and recessive allele Genotypic Ratio: Phenotypic Ratio:

Draw a Punnett Square to show the offspring when two heterozygous pink plants are crossed? Genotypic Ratio: Phenotypic Ratio:

Genotypic Ratio: Phenotypic Ratio:

• CODOMINANCE- neither of the 2 alleles of the same gene totally masks the other. The result is a combination of both dominant traits.

• Rule: Use two different letters to represent the alleles. Because they are both dominant they should both be capitalized.

• Make a Punnett Square to show this cross. Genotypic Ratio: Phenotypic Ratio:

CODOMINANCE R = red colored coat W= white colored coat R R W RW RW RR x WW All offspring will be …. . ? Roan (red and white)

CODOMINANCE R = red colored coat W= white colored coat R R W RW RW RR x WW Genotypic Ratio: 0: 4: 0 Phenotypic Ratio: 0: 4: 0

Reflection: Success Criteria

Incomplete Dominance and Codominance Practice

Bell Work: Cross a heterozygous for Round (dominate trait) pea plant with a homozygous recessive (wrinkled) pea plant. What is the phenotypic and genotypic ratio? Assignment: Sex-Linked Traits - Finish Incomplete/Codominance Stamp: Incomplete/Codominance Assignment

Bell Work • What are the different blood types? • What is the difference between the sex chromosomes in males and females? • Stamp: Incomplete Dominance/Codominance Worksheet

Blood Types • There are 6 genotypes. • They make up 4 phenotypes (blood types). • A and B are codominant, and O is recessive. Genotype Phenotype (Blood Type) IAIA or AA A A IAi or AO IBIB or BB IBi or BO IAIB or AB ii or OO B B AB O The I designation stands for isoagglutinogen, another term for antigen.

What are the possible blood types of the potential children of an AB (IAIB) male and an B (IB i) female? What % chance will the offspring be type B? Hint: use a punnett square

IAIB x I Bi What are the possible blood types of the potential children of an AB (IAIB) male and an B (IB i) female? What % chance will the offspring be type B?

Reflection: Which blood type is considered a universal donor? Universal recipient? Explain how this works.

Bell Work: A woman that is heterozygous with type A blood is married to a heterozygous type B person. What blood types will their children have? Assignment: Sex-Linked Traits/Practice Stamp: Blood Types

• What are the sex chromosomes for males? Females?

AUTOSOMAL TRAITS LOCATED ON ALL OF YOUR AUTOSOME CHROMOSOMES. YOU HAVE AUTOSOMAL RECESSIVE & AUTOSOMAL DOMINANT TRAITS.

SEX LINKED TRAITS • THESE ARE TRAITS LOCATED ON THE SEX CHROMOSOMES. • MALES PASS GENES LOCATED ON THE “X” CHROMOSOME TO ALL OF THEIR DAUGHTERS & NONE OF THEIR SONS. • WHATEVER MOM HAS ON HER “X” CHROMOSOME WILL BE EXPRESSED IN HER SONS EVEN IF THE TRAIT IS RECESSIVE.

SEX LINKED ( X-LINKED) Hemophiliac mom H= non hemophilia h= hemophilia Normal dad WHAT ARE THE CHANCES OF HAVING A CHILD WITH HEMOPHILIA? IF THEY HAVE A SON, WHAT ARE HIS CHANCES OF HAVING HEMOPHILIA?

SEX LINKED ( X-LINKED) H= non hemophilia X h x X HY h= hemophilia WHAT ARE THE CHANCES OF HAVING A CHILD WITH HEMOPHILIA? IF THEY HAVE A SON, WHAT ARE HIS CHANCES OF HAVING HEMOPHILIA?

SEX LINKED ( X-LINKED) H= non hemophilia X h x X HY h= hemophilia Xh Xh XH Y WHAT ARE THE CHANCES OF HAVING A CHILD WITH HEMOPHILIA? IF THEY HAVE A SON, WHAT ARE HIS CHANCES OF HAVING HEMOPHILIA?

SEX LINKED ( X-LINKED) H= non hemophilia X h x X HY h= hemophilia XH Y Xh Xh X HX h X h. Y WHAT ARE THE CHANCES OF HAVING A CHILD WITH HEMOPHILIA? IF THEY HAVE A SON, WHAT ARE HIS CHANCES OF

SEX INFLUENCED TRAITS • THE PRESENCE OF MALE OR FEMALE HORMONES INFLUENCES THE EXPRESSION OF CERTAIN TRAITS. – EX: PATTERN BALDNESS • IF FEMALE IS HETEROZYGOUS SHE WILL NOT BE BALD. -She will be a carrier XBXb • IF A MALE RECIEVES THE RECEESIVE TRAIT FROM HIS MOM, HE WILL BE BALD. – Xb. Y

Calico is a coat color found in cats, which is caused by a SEXLINKED, CODOMINANT allele. B = black, R = orange, and BR = calico. The following genotypes are possible; Female cats can be black XBXB, orange XRXR, or calico XBXR Male cats can be black XBY or orange XRY Show each of the crosses below and include the phenotypic of the offspring. A black male crossed with an orange female cats can be black XBXB, orange XRXR, or calico XBXR Male cats can

How would you be able to tell if a trait is sex-linked versus autosomal?

Bell Work: Write a genotype that represents an organism that is homozygous dominant, another one that is homozygous recessive, and a third that is heterozygous for a trait. Use whatever letter you choose. Assignments: Vocabulary Quiz Pedigrees

Bell Work: What are some genetic disorders you have heard of before? Assignments: Finish Notes/Pedigrees Stamps: Genetics Review Packet Page 1 -13

ENVIRONMENTAL EFFECTS • Many alleles are expressed depending on the environment. –Some are heat sensitive • Ex: Arctic foxes make fur pigment only when the weather is warm.

CAN YOU SEE WHY THIS TRAIT WOULD BE AN ADVANTAGE?

Continuous Variation • Most traits are polygenic – They result from the action of more than one gene • These genes contribute in a cumulative way to the phenotype – The result is a gradation in phenotypes or continuous variation Extremes are much rarer than the intermediate values

EPISTASIS • INTERACTION BETWEEN THE PRODUCTS OF TWO GENES IN WHICH ONE OF THE GENES MODIFIES THE PHENOTYPIC EXPRESSION PRODUCED BY THE OTHER. – EX: COAT COLOR FOR LABRADOR RETRIEVERS.

• The E gene determines if dark pigment will be deposited in the fur or not. • If the dog has ee there is no pigment & dog will be yellow. • The B gene determines how dark the pigment will be. • In yellow labs the B gene indicates the color on their nose, lips, & eye rims.

E_B_=black E_bb=chocolate/br own

B gene=black ee. B_ b= brown eebb

SOME GENETIC DISORDER AUTOSOMAL RECESSIVE: ALBINISM CYSTIC FIBROSIS WILSON’S DISEASE TAY-SACHS DISEASE AUTOSOMAL DOMINANT HUNTINGTON’S DISEASE POLYDACTYLY PROGERIA DEAFNESS Achondroplasia (dwarfism): AA = Homozygous dominant is lethal - fatal (spontaneous abortion of fetus). Aa = dwarfism. aa = no dwarfism. 99. 96% of all people in the world are

Do you recognize this family? *Hint: They are from a TV show

• They are the Roloff family from TLC’s show Little People Big World Some family members (including the parents) exhibit the characteristic short stature of Achondroplasia, a dominant genetic disorder that results in a form of dwarfism.

EXPLORATION ACTIVTIY: • How is it possible for Matt and Amy (the parents) to have a child like Zach with Achondroplasia, dominant genetic disorder, and children who do not have the disease?

• How many children did Matt and Amy have? • How many were average height and how many have dwarfism. • Use a Punnett Square to show the possible genotypes of Matt and Amy’s offspring. • Write the genotypic and phenotypic ratios.

DID YOU QUICKLY THINK, Since some of the Roloff children do not exhibit dwarfism, what do we know about Matt and Amy’s genes for Achondroplasia? THAT’S RIGHT!!! Matt and Amy both have an Aa genotype. This would allow them to have children who exhibit dwarfism as well as children of normal height. Dwarfism: Aa Normal height: aa Why not ever AA?

X-LINKED: HEMOPHILLIA COLORBLINDNESS

Why are lethal dominant traits less common in a population than lethal recessive traits?

Pedigree’s • A pedigree is a diagram of family relationships that uses symbols to represent people and lines to represent genetic relationships. These diagrams make it easier to visualize relationships within families, particularly large extended families. Pedigrees are often used to determine the mode of inheritance (dominant, recessive, etc. ) of genetic diseases. • If the purpose of a pedigree is to analyze the pattern of inheritance of a particular trait, it is customary to shade in the symbol of all individuals that possess this trait.

• In a pedigree, squares represent males and circles represent females. Horizontal lines connecting a male and female represent mating. Vertical lines extending downward from a couple represent their children. Subsequent generations are therefore written underneath the parental generations and the oldest individuals are found at the top of the pedigree.

Construct a Pedigree • A man and woman have 5 children (2 girls and 3 boys). The mother is a carrier of hemophilia (an Xlinked disorder). She passes the gene onto her 2 boys who later die in childhood. One daughter also inherits that gene and is a carrier. Both daughters marry men without hemophilia and have 3 children each (2 boys and a girl). The carrier daughter has 1 son with hemophilia. One of the non-carrier daughter’s sons marries a woman who is a carrier and they have identical twin daughters. What is the percent chance that each daughter will also be a carrier?

ALBINISM

TRISOMY 13 – PATAU’S SYNDROME

PROGERIA

POLYDACTYLY

Bell Work What were Mendel’s laws? Assignment: Genetics Test Darwin Intro

MENDEL’S LAWS • LAW OF SEGREGATION - -Reproductive cells only receive one factor of each pair. • LAW OF INDEPENDENT ASSORTMENT: -The factors for different characteristics are not connected

Darwin Questions: Page 450 1. What is evolution? 2. What ideas were changing in the scientific community at the time of Darwin’s travels? 3. What was Darwin’s contribution to science? 4. What year did Darwin begin his voyage? What was the name of the ship he was on? 5. What modern phenomenon does Darwin’s perspective help us understand? 6. What 3 patterns of biodiversity did Darwin note? 7. What famous group of islands did Darwin visit? Why was this set of islands ideal for studying variation? 8. What do you think the difference is between an inherited an acquired trait?