1. Do Now 3/9/17 How does this all work?!?!
Can two parents with brown hair, have a child with blond hair? (yes/no)
Can two parents with blue eyes have a child with brown eyes? (yes/no)
Can parents, one with brown eyes and one with blue eyes have a child with green eyes? (yes/no)
How does this all work?!?!
Homework: Trait Wheel packet due Monday

2. Genetics!

3. Terms Review Heredity Trait Genetics
Passing of physical characteristics from parent to offspring
Trait
Different forms of characteristics (eye color etc…)
Genetics
The scientific study of heredity and traits

4. Reproduction
Sexual reproduction – requires sex cells, happens when the two sex cells (egg and sperm) join together
Process of joining is called fertilization
Asexual reproduction – does not require sex cells for reproduction

5. Gregor Mendel
Experimented with thousands of pea plants back in the 1800’s
He used controlled fertilization of plants to see what happens to traits through the generations
Fertilization
The process of an egg and sperm cell joining to form a new organism

6. Gregor Mendel
He crossed (forced reproduction of) plants with different traits
Tall with short
Pink flowers with white flowers
He always started with purebred organisms
Purebred
Means they have the same allele twice (DD, rr)

7. Gregor Mendel - Plants
First generation of plants he called the “P” generation (parent).
Crossed one tall (TT) and one short (tt). Each was purebred.
Notice the traits of the offspring in the “F1” generation (offspring)
All tall

8. Gregor Mendel - Plants
He then took plants from the F1 generation and crossed two of them.
Notice the traits of the second (F2) generation
Three are tall, one is short

9. Gregor Mendel - terms
By crossing plants, he learned about dominant and recessive alleles
Alleles – differing forms of a gene
Gene – located on a chromosome, controls traits
Chromosome – compressed form of DNA
Dominant Allele – trait will always show up, even with only one present
Recessive Allele – trait needs two alleles present to show up. Hidden by one dominant allele

10. Mendel’s Plants Parent Generation – (TT) X (tt)
Possible outcomes for F1? Tt
F1 Generation – (Tt) X (Tt)
Possible outcomes for F2?
TT, Tt, tt
When an organism has two different alleles for a trait (Tt) it is called a hybrid

11. Do Now 3/10/17
What determines which allele your parent pass on to you?
Homework: trait wheel packet due Monday

12. Probability and Heredity
Probability – number that describes how likely an event is
Coin flipping
2 options – heads, tails
Probability of heads is ½ or 50%
Probability of tails is ½ or 50%

13. Probability and Heredity
When you toss a coin and it lands heads, what is the probability of heads on the next flip?
Still ½ or 50%
Probability deals with each flip individually.
What would be the results of flipping a coin 10 times?
Not always 50% heads 50% tails

14. Probability and Heredity
Which alleles you get from your parents are all based on probability and statistics
You have 50% chance of getting either allele for each trait (T or t)

15. Probability and Mendel
Mendel crossed the F1 generation (Tt)
¾ or 75% of the offspring were tall
¼ or 25% were short
First scientist to see that probability applied to heredity

16. Punnett Squares
Punnett square – chart that shows all the possible combinations of alleles from a genetic cross

17. Punnett Squares
Take both alleles from each parent and place them outside the square
Parents are (Rr) X (Rr)
R is dominant for red
r is recessive for white
What color are the parents?
Both red

18. Punnett Squares
Carry the alleles across or down the table to place them in the correct place.

19. Punnett Squares
You can count the small squares at the end to see probability
Outcomes are
RR – 1/4
Rr – 2/4
rr – 1/4
If R is the dominant allele for red color and r is the recessive allele for white color, what is the probability of having a white offspring?
¼ or 25%

20. Punnett Squares 0/4 or 0% Try another one! B B b B b B b B b b B b
Guinea pigs have the dominant allele (B) for black fur and recessive allele (b) for white fur
If we crossed one black (BB) and one white (bb), what is the probability of having a white offspring? B B
0/4 or 0% b
B b
B b
B b b
B b

21. 3/13/17 DO NOW Homework Have out homework
One parent is (Rr) and another parent is (rr). Complete the Punnett square for this cross to state what the percent change of having purebred, recessive offspring would be.
Homework
Bikini Bottom Genetics (first page) due tomorrow

22. “Types” Phenotype – physical appearance based on its genes
Genotype – genetic makeup or combination of alleles

23. “Zygous” Purebreds have 2 of the same allele (TT) or (tt)
Another name for this is homozygous
Hybrids have 1 of each allele (Tt)
Another name for this is heterozygous
A heterozygoat!

24. Weird Crosses Incomplete dominance
Happens when both alleles are expressed by blending together in hybrids (heterozygous)
Plant has alleles for red and white, a mix produces a pink flower
No “dominant” or “recessive” in these types of problems.

25. Weird Crosses Co-dominance Cows
When both alleles are equally expressed in the hybrid (heterozygous) offspring
Cows
RR – brown
rr – white
Rr – “Roan”

26. Weird Crosses Sex-Linked traits
Happens only with genes that are found on the “X” chromosome
Expressed differently by gender. Why??
Because females have two “X” chromosomes and males have one “X” chromosome

27. Carriers
A carrier refers to someone who has an allele for a trait, but does not display the trait
Someone with brown eyes who has the alleles (Bb) is a “carrier” for blue eyes