1. Objective:
I Can…….
A) explain the differences between dominant and recessive traits.
B) explain the differences between phenotypes and genotypes.

2. Chapter 8 “Heredity” Mendelian Genetics 11/7/2018
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3. Why don’t you look exactly like your parents?
You don’t look exactly like your parents because of what is known as “ heredity’.
1.) Heredity is the passing of traits from parent to offspring.
You may have curly hair while both your parents have straight hair or blue eyes while both of your parents have brown eyes
People have investigated this question for a long time.
About 150 years ago, Gregor Mendel performed an important experiment which helped find answers to many of our questions.

4. Mendelian Genetics
11/7/2018
2.) Gregor Mendel ( )
Is credited for the theories that explain how are traits are inherited from generation to generation.

5. Mendelian Genetics
11/7/2018
Gregor Johann Mendel
Was an Austrian monk who studied the inheritance of traits in pea plants. He was also great in Math, which helped him to better understand his research.
3.) He developed the laws of inheritance. He is also known as the “Father of Genetics."
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6. Mendel’s Pea Plant Experiments
Mendelian Genetics
11/7/2018
Mendel’s Pea Plant Experiments
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7. Mendelian Genetics
11/7/2018
Let’s look back for a second: remember that whole Reproduction thing in Flowering Plants????
Pollen contains the male sex cell ( sperm). It is Produced by the _______.
Female sex cells (eggs) are the _______. These are located inside the _____ of the flower.
Flowers are able to reproduce with the help of bees and other living organisms.
anther
ovules
ovary

8. Two types of fertilization in Flowering Plants
Mendelian Genetics
11/7/2018
Two types of fertilization in Flowering Plants
Pollen carries sperm to the eggs for fertilization. Fertilization can occur by:
a)_____________ can occur in the “same” flower.
Self-pollination
b) ____________ can occur between two “different” flowers.
Cross-pollination

9. Mendelian Genetics
11/7/2018
How Mendel Began
Mendel produced pure strains of plants by allowing plants to “self-pollinate” for several generations
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10. Mendel’s experiments…
From working with these plants, Mendel noticed that the patterns of inherited traits were not always clear.
Sometimes traits would appear in one generation and be absent in another generation. In generations afterwards, the trait would “reappear” again.
Mendel noticed this also occurred in other organisms as well, so he wanted to learn more about “what caused these patterns”
To keep his investigation simple, Mendel decided to study plant, since he had already done research on them before.
How do you think Mendel’s experiment relates to you and your family?

11. Mendel studied only one characteristic at a time…
4.) A characteristic is a feature that has different forms in a population. (ex: hair color)
What are some more examples of characteristics a person may have?
4.) Any characteristic that can be passed from a parent to his/her offspring are called “Traits”. These traits can come in different forms such as red hair, brown hair, etc… .

12. “Trying it all”…..
Mendel used different plants that had different traits for each of the characteristics he studied.
The results:
All of the flowers were purple? Are you surprised?
What happened to the traits of the White flower?
Mendel’s First experiment:
Mendel used plants that were “true-breed” to get different traits for each characteristic.
(ex: purple flower + white flower)

13. 5.) Dominant and Recessive..
Mendel noticed that from crossing the plants, one trait was always present and the other seemed to have disappeared.
Mendel chose to call these traits:
A) Dominant
B) Recessive
A.) Dominant traits are those that appear or are “visible”.
B.) Recessive traits are those that are “hidden”.

14. Back to Gregor Mendel…
Mendel knew that from his experiment there must be two sets of instructions (one given from each parent).
6.) We now call these instructions “genes”.
Each parent gives one set of genes to the offspring. The offspring then has two forms of the same gene for every characteristic –(one from each parent) .

15. What’s in your “genes”…….
B= brown-eyed b= blue-eyed
7.) The different form of a gene (such as “dominant” or recessive”) is called an allele.
8.) Dominant alleles are represented by a Capital letter.
8.) Recessive alleles are represented by a lower-case letter.

16. Quick check: How many alleles make up an gene?
Where does each allele come from?
Scenario: You have “freckles”. Your mom has rosy cheeks, but dad has freckles also. What is the dominant gene in this example?
Now write an example of an allele to represent the freckles and an example to represent the rosy cheeks.
Possible Answer:
FF= freckles
ff= rosy cheeks

17. BrainPop!
Get ready to take notes on your sheet…give at least 3 important NEW pieces of information
BrainPop: Genetics

18. Genes affect the traits of offspring….
Mendelian Genetics
11/7/2018
Genes affect the traits of offspring….
9.) An organism’s “physical appearance” is known as its phenotype.
( ex: color of plants: purple or white
Shapes : round or wrinkled
In humans phenotypes are little more complicated.
(Ex: Albinism in humans is even considered a phenotype).
Describe the phenotype of
this flower.
Red and
Yellow
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19. Genes affect the traits of offspring….
Mendelian Genetics
11/7/2018
Genes affect the traits of offspring….
10.) An organism’s “genetic make-up appearance” is known as its genotype.
10.) All genes occur in pairs, so 2 alleles affect a characteristic
Possible combinations are:
Genotypes RR Rr rr
Phenotypes RED RED YELLOW
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20. Mendelian Genetics
11/7/2018
11.) Genotypes
A.) Homozygous genotype – allele combination involving 2 dominant or 2 recessive alleles Homozygous genotypes are also called “pure” genotypes. 
(e.g. RR or rr)
B.) Heterozygous genotype - gene combination of one dominant & one recessive allele. These are     also called “hybrid” genotypes.
(e.g. Rr)
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21. Genotypes represent the “genetic make- up” of the organism.
Remember!!!
Genotypes represent the “genetic make- up” of the organism.

22. Phenotypes represent the “physical appearance” in the organism
Remember!!!
Phenotypes represent the “physical appearance” in the organism
What are some words you can use to
Describe the phenotypes in this slide?

23. Quickcheck???? What does “homozygous” mean? “Heterozygous”?
How many of each type is shown here?

24. 12.) Punnett Squares: What are they and why do we use them?
Are used to help solve genetics problems
2) It organizes all the
possible combinations of
offspring from particular
parents.
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25. Y= yellow pea
y= green pea 25

26. Get some practice….
Create a Punnet Square to predict the offspring of two plants that produce round seeds. The “genotype” for each parent is Rr.
Round seeds are dominant and wrinkled seeds are recessive.
R=round
r= wrinkled
What will the offspring look like?
Work this problem first with the kids….think aloud!!! To go through your steps!!!...USE A EXPO MARKER TO DRAW ON THIS PAGE BEFORE SHOWING THE RESULTS…..use the next slide as a review of how we solved the problem….. 26

27. Practice problem …. R r RR Rr R r Rr rr Trait: Seed Shape
Mendelian Genetics
11/7/2018
Practice problem ….
Trait: Seed Shape
Alleles: R – Round r – Wrinkled
Cross: Rr x Rr
What will the offspring look like?
What are the Genotypes?:_________
What are the Phenotypes?:________
What percent is “round”? “Wrinkled”? R r RR Rr R r Rr rr
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28. Here’s your answer…. R r RR Rr R r Rr rr Trait: Seed Shape
Mendelian Genetics
11/7/2018
Here’s your answer….
Trait: Seed Shape
Alleles: R – Round r – Wrinkled
Cross: Rr x Rr
Three of the offspring are Round and one is wrinkled.
What are the Genotype?: RR, rr, Rr
What are the Phenotype?: Round & Wrinkled
What percent is round? Wrinkled? 75% Round 25% wrinkled R r RR Rr R r Rr rr
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29. Sample Problem #1 What are the Genotypes?__________
Mendelian Genetics
11/7/2018
Sample Problem #1
Trait: Seed Shape
Alleles: R – Round r – Wrinkled
Cross:
“homozygous”Round seeds x “Heterozygous” Round seeds
RR x Rr
What are the Genotypes?__________
What is the Phenotype(s)? _______________
What percent is round? Wrinkled? ________
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30. Sample problem #2: Trait: Seed Shape Alleles: R – Round r – Wrinkled
Mendelian Genetics
11/7/2018
Sample problem #2:
Trait: Seed Shape
Alleles: R – Round r – Wrinkled
Cross: Wrinkled seeds x Round seeds
rr x Rr
What is the Genotype(s)?
What is the Phenotype(s)?
What percent is Round? What percent is Wrinkled?
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31. Cross 2 Pure Plants TT x tt
Mendelian Genetics
11/7/2018
More practice: below your Punnett Square boxes, predict the offspring of the plants crossed below.
T= Tall plants
t = short plants
b) What are your results by Crossing two of the offspring?
Cross 2 Pure Plants TT x tt
a) What are your results?
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32. Here’s your Answer: How did you do????
Mendelian Genetics
11/7/2018
Here’s your Answer: How did you do????
b) What are your results by Crossing two of the offspring?
Cross 2 Pure Plants TT x tt
a) What are your results?
All of the
Offspring are
(Tt)
3 Tall & 1 short
(TT, Tt, & tt)
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