Introduction to Genetics-Blackboard

GENETICS : 

GENETICS

An Inventory of Our Traits: 

An Inventory of Our Traits Trait Yes No Widow’s Peak Unattached Ear Lobes Mid-digital Hair Cross Left  Right Hitchhiker’s Thumb Freckles Cleft Chin Dimples Roll Tongue Can Taste PTC Can See Red and Green

ARE ALL TRAITS INHERITED?: 

ARE ALL TRAITS INHERITED?

The Work of Gregor Mendel: 

The Work of Gregor Mendel Known as the “_________ ______________” Born in 1822 to a poor family in the ________ ________ Mendel excelled in school and eventually became a ________. FATHER Czech OF GENETICS Republic monk

The Work of Gregor Mendel (con’t): 

The Work of Gregor Mendel (con’t) In addition to his monastery duties, he taught high school _______. Mendel also was in charge of the monastery _________. science garden

Site of Gregor Mendel’s experimental garden in the Czech Republic: 

10 Site of Gregor Mendel’s experimental garden in the Czech Republic

Gregor Mendel (con’t): 

Gregor Mendel (con’t) Mendel worked with garden _______ and studied how their characteristics are passed in a very ______________ manner to their offspring. He tested about 28,000 pea plants! peas predictable

Gregor Mendel (con’t): 

Gregor Mendel (con’t) The scientific community ___________ his work stating he, “ oversimplified an obviously complex mechanism .” His studies were totally forgotten for the next ______. It was then that ______ independent scientists discovered his paper and realized their data matched with Mendel’s!! Sadly, Mendel had died by this time and never knew the impact that he would have on the scientific future. disregarded 34 yrs three

The Anatomy of a Flower: 

The Anatomy of a Flower Sepal Petal Ovary Anther Filament Style Stigma

The Anatomy of a Flower: 

Stamen (_____ parts) Filament – long stalk that the _______ sits upon Anther –_______producer Pistil ( ______ parts) Stigma – opening at the top of the ______. Style – long neck of the pistil Ovary – where __________ occurs. This is where the _______ comes form. The Anatomy of a Flower male anther pollen female pistil fertilization fruit

How a Plant is Fertilized: 

How a Plant is Fertilized _______ grains from the _______ contain the sperm cells. These become mobile by wind or animal When a pollen lands on a _________ it grows a long tube that extends into the _____. The sperm cells move to the ovary and ____________ occurs. A ________ has now developed that will eventually grow into a ________. Pollen ovary stigma anther fertilization seed fruit

Two Types of Fertilization: 

Two Types of Fertilization True-Breeding: plants produce _______ offspring through self-pollination identical

PowerPoint Presentation: 

Cross-Breeding: plants produce offspring through ______________________. Two Types of Fertilization Cross -pollination

Mendel’s Experiment: 

Mendel’s Experiment Mendel self-pollinated ________ plants and noticed he always got ______ plants as a result. The same happened with ______ plants. These he called __________ plants tall tall short “purebred”

Mendel’s Experiment: 

Mendel’s Experiment Next, he decided to cross-pollinate ________ traits. To do this, he removed the ______ of each plant and dusted the Pistil with pollen from a second flower opposite stamen

PowerPoint Presentation: 

This Table shows the two parents he crossed (P) and the resulting offspring (F1). F stands for First _______, which means “ son ” in Latin. Filial

Mendel’s Conclusions: 

Mendel’s Conclusions All of the F 1 generation had the character of only ____ parent. 2. Traits are passed from one generation to the next. Today we know that these traits are controlled by sections of DNA called ________. one genes

Mendel’s Conclusions: 

Mendel’s Conclusions Different forms of a gene are called ___________. alleles Which of the genes to the right, A, B, or C has the same allele? ____________ B

Mendel’s Conclusions: 

Mendel’s Conclusions Mendel concluded that some alleles are ___________, while others are __________. dominant recessive

Mendel Still Confused: 

Mendel Still Confused Had the recessive alleles disappeared from the F 1 generation, or were they just __________? Mendel decided to cross ______ plants from his F 1 generation to make an F 2 generation. masked Tall

Mendel Surprised!: 

Mendel Surprised! Did the short trait appear in the F 2 generation? ______ Determine the ratio of tall to short _____: _____ yes 3 1

Mendel Explained the Results: 

Mendel Explained the Results The reappearance of the trait in the F 2 generation indicated that at some point the ________ are separated. This is referred to as ___________ of alleles. This separation must occur during the formation of sex cells, or ________. alleles segregation gametes

Segregation Illustrated: 

Segregation Illustrated T = tall t = short

Probability and Punnett Squares: 

Probability and Punnett Squares Mendel developed a technique to __________ what offspring you would get from a cross. It is called a ______________. predict Punnett Square

Probability and Punnett Squares: 

Probability and Punnett Squares He assigned each gene a letter. The dominant version uses the _______ form of the letter, while the recessive uses the _________ version. Example: R = round r = wrinkled CAPITAL lower-case

Homozygous vs. Heterozygous: 

Homozygous vs. Heterozygous RR = Purebred pea plant for the Round Allele. Since ____ alleles are the same, this type of plant is called _________________________. rr = Purebred pea plant for the wrinkled allele. This is called _________________________. R r = this organism has two ________ alleles and is therefore called a _________, or __________. both Homozygous Dominant Homozygous Recessive Heterozygous different Hybrid

Punnett Squares – F1: 

Punnett Squares – F 1 R r R r R r R r R R What % of these seeds will be round? __________ r r P 100%

Punnett Squares – F2: 

Punnett Squares – F 2 RR R r R r rr R r R r F 1 The F 2 generation looks very different from the F 1 generation.

Genotype vs. Phenotype: 

Genotype vs. Phenotype Genotype: __________ makeup Phenotype: _______characteristics The F 1 cross results in 3 Genotypes: _____, _____, _____ The F 1 cross results in 2 Phenotypes: ________, ________ Phenotypic Ratio___ : ____ Genetic Physical RR R r rr Round Wrinkled 3 1

Practice Problem #1: 

Practice Problem #1 In purple people eaters, one-horn is dominant and no horns is recessive. Draw a Punnett Square showing the cross of a purple people eater that is hybrid for horns with a purple people eater that does not have horns. Summarize the phenotypes of the possible offspring.

PRACTICE PROBLEM (con’t): 

PRACTICE PROBLEM (con’t) H h h h Hh hh Hh hh

Practice Problem #1: 

Practice Problem #1 Phenotypes: ______________ , _____________, _____:____ OR _____:____ Phenotypic Ratio Horns No horns 2 2 _ 1 1 _

Practice Problem #2: 

Practice Problem #2 The ability to roll the tongue is dominant (T) over the inability (t) to do so in humans. If a non-tongue-roller has children with a homozygous tongue-roller, what will their children’s genotypes be?

PRACTICE PROBLEM (con’t): 

PRACTICE PROBLEM (con’t) t t T T Tt Tt Tt Tt

Practice Problem #2: 

Practice Problem #2 Phenotypes: ______________ , _____________, _____:____ OR _____:____ Phenotypic Ratio Tongue-roller Non-roller 4 0 1 0 _

Independent Assortment: 

Independent Assortment Mendel wondered if alleles segregated __________, that is, if a seed is round, must it also always be yellow? Mendel performed a ___________ cross, in which he crossed true breeding round, yellow peas with true breeding wrinkled, green peas. Two-factor independently

Mendel’s Two-Factor Cross: F1: 

Mendel’s Two-Factor Cross: F 1

Mendel’s Two Factor Cross: F2: 

Mendel’s Two Factor Cross: F 2

Mendel’s Two Factor Cross: F2: 

Because the F 1 cross resulted in a variety of phenotypes, genes do not influence each other’s inheritance. This principle is known as _____________________. THESE TRAITS ARE NOT LINKED TOGETHER Mendel’s Two Factor Cross: F2 Independent assortment

Practice Problem # 3: 

Practice Problem # 3 We will examine a dihybrid cross involving both color and texture. Purple ( P ), is dominate to yellow ( p ), and smooth texture ( S ) is dominant to wrinkled ( s ). Both parent plants are heterozygous for both traits.

Practice Problem #3(con’t): 

Practice Problem #3(con’t) Plant # 1 = PpSs Plant # 2 = PpSs

Practice Problem #3: 

Practice Problem #3 PS Ps pS ps Ps PS pS ps PPSS PPSs PpSS PpSs PPSs PPss PpSs Ppss PpSS PpSs ppSS ppSs PpSs Ppss ppSs ppss

Practice Problem #3: 

Practice Problem #3 Phenotypes: ______________ , _____________, ______________ , _____________ ____:_____:_____:_____ Phenotypic Ratio Purple, Smooth Purple, Wrinkled Yellow, Smooth Yellow, Wrinkled 9 3 3 1 9/16 3/16 3/16 1/16

Beyond Dominant and Recessive Alleles: 

Beyond Dominant and Recessive Alleles Some alleles are neither ___________ nor ____________, and many traits are controlled by multiple __________ or multiple genes. Incomplete Dominance, Codominance, Multiple Alleles, and Polygenic Traits dominant recessive alleles

Incomplete Dominance: 

Incomplete Dominance

Codominance of Cattle : 

Codominance of Cattle

Codominance of Cats: 

Codominance of Cats

Multiple Alleles: 

Multiple Alleles There are 3 different alleles for blood type, (I A , I B , i ). I A & I B are both codominant . I A is dominant to i and I B is dominant to i . i .

Polygenic Traits: 

Polygenic Traits Height is a result of multiple genes

Eye Color is the result of multiple genes: 

Eye Color is the result of multiple genes