1. Genetics & Evolution
Today’s Goal
I can complete a Punnett Square
I can name two people and their contributions to genetics
Homework Finish Vocab up to and including mutation. Study for Vocab Quiz
Warm-up: Explain the quote “If I have seen further, it is by standing on the shoulders of giants” and apply this quote to Darwin’s theory and his influences Malthus and Lyell
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2. What is Genetics?
Genetics – The study of how heredity information is passed from parents to offspring

3. The Modern Theory of Evolution =
What is Genetics?
The Modern Theory of Evolution =
Genetics + Darwin’s Theory of Natural Selection

4. Law of Dominance (see above)
Gregor Mendel
Studied inheritance of traits in pea plants
Published research shortly after Darwin’s book (but it was in an obscure journal)
He received credit for his work in 1900 (15 years after his death)
The pea traits he studied later became known as GENES
He became the Father of Genetics
Law of Dominance (see above)

5. What is DNA? DNA = Deoxyribonucleic acid DNA stores information
Subunit = nucleotides
DNA IS DOUBLE STRANDED
Nucleotides contain a nitrogen base
4 different nitrogen bases
adenine (A)
guanine (G)
thymine (T)
cytosine (C)
Complimentary Strands (A-T) (G-C)
DOUBLE HELIX
*3,000,000,000 nitrogen base pairs make you who you are*

6. What is a Gene?
Your body is made up of cells
Each cell in your body contains a nucleus
Each nucleus contains pairs of chromosomes
Chromosomes contain your DNA sequence
A segment of DNA is called a gene
A gene codes for a specific trait
Most cells in your body have 46 chromosomes. Sperm and Egg cells have 23 chromosomes.

7. James Watson & Francis Crick and Rosalind Franklin(1953)
Franklin’s x-ray of the DNA molecule – view is above helix, looking down (x pattern is from nucleotide bases)
Discovered the structure of a DNA molecule (double helix) which provided details on genes & how they work

8. What is an Allele?
Most organisms have TWO copies of every gene and chromosome (one from each parent)
Alleles are the different forms of a gene for a specific trait
Ex: Flowers can be violet or white

9. What is an Allele?
REMEMBER genes exist as pairs, so often one allele is considered the dominant allele and the other the recessive allele
Dominant: trait observed in the first generation when parents that have different traits are bred
Given a capital letter symbol (ex: Purple flower= P)
Recessive: a trait that reappears in the second generation after disappearing in the first generation when parents with different traits bred
Given a lower case letter symbol (ex: White flower= p)
Which is the purple allele?
Purple is dominant because it “covers up” the white allele in the offspring

10. Dominant & Recessive Alleles
Since genes are found in pairs, a pea plant could have the following combinations of alleles for flower color
PP = purple Pp = purple pp = white
The genetic make-up is called the genotype (PP, Pp, or pp)
PP and pp is considered homozygous (all one allele type)
Pp is considered heterozygous (two different allele types)
The outward physical appearance for a gene is called the phenotype (purple or white), which is based on its genotype

11. LETS DO SOME PRACTICE PROBLEMS!
is a diagram that is used to predict an outcome of a particular cross or breeding experiment.
Punnett Square
P = purple
p = white
What are the chances of having the white phenotype?
What are the chances of carrying the white allele?
What is the chance of having a heterozygous genotype?
¼ or 25 %
½ or 50 %
½ or 50 %
LETS DO SOME PRACTICE PROBLEMS!

12. PRACTICE! TT x tt Tt Tt x Tt 25% 50% 25% 100 % offspring = ____

13. Bb Bb BB Bb Bb bb

15. Complete Observing Human Traits Lab

16. Genetics & Evolution Warm-up: Today’s Goal
I can complete a Punnett Square
I can describe how mutations occur
Homework Finish DR How does Evolution occur AND Study for vocab quiz TOMORROW
Warm-up:
5 minutes

18. DNA Code and Mutations
The DNA Sequence shows how a species changes over time
If a mutation (typo) occurs within the DNA sequence, genes can change causing alleles and traits to change
Over time as more mutations accumulate the species changes

19. A A G A G Normal DNA (gene):
Let’s say that “AAAGGG” means that you can break down a chemical in milk called phenylalanine
The same sequence is copied to make egg (female) or sperm (male): A G

20. All egg or sperm cells will have the same sequence of “AAAGGG” so all offspring will be able to break down milk A G
Unless something goes wrong when the gene is copied: A A A C G G
Now this egg or sperm cell is carrying a mutation of the gene. Offspring who are born with this gene cannot break down phenylalanine from milk, which causes brain damage when it builds up in the body.

21. This mutation has led to 2 different variations within the population:
Some babies will be disease free and can break down phenylalanine in milk
Some babies will have a disease (called Phenylketonuria) and cannot break down this protein in milk

23. Human Genome (2001) All living things are made of genetic information
We have similarities in our DNA to all animals including dogs and fruit flies.
The more closely related two species are to each other the more similar their DNA code (genome)
Find out your genetic code
23andMe (was $999, now $99)
Visit:
Other: deCODE; Navigenics

24. 23 and Me Created by one of the founders of Google
Would you use 23 and me?