1. Heredity
By: Mr. Kauffman

2. Outline What are genes? Gregor Mendel Where can we find our genes?
What do our genes do?
Our Genes
Genetic Trait Tree
Where do we get our genes from?
Inheritance
Predicting Inheritance
Modern uses of DNA technology

3. What are genes?
Heredity: the passing of genes from parents to offspring (children)
Gene: a specific part of DNA that controls a hereditary trait
Hereditary traits are characteristics that can be passed from parents to their offspring

4. Inherited vs. Acquired Characteristics
Inherited characteristics: characteristics that are controlled by genes/DNA passed from parents to their offspring
Examples -> height, natural hair color, eye color
Acquired characteristics: characteristics that can be developed or altered during a person’s lifetime
Examples -> tattoo, learning to play a sport, learning to play a musical instrument

5. Gregor Mendel Austrian monk
Considered to be the father of modern Genetics
Used pea plants to demonstrate how certain characteristics were passed through generations
Seed shape, seed color, flower color, pod shape, pod color, and stem height

6. Mendel’s Work

7. Where can we find our genes?
We have 1000’s of genes and each one is found at a specific location on a specific chromosome
What does that mean?
All genes are found in specific places
Everyone has different combinations of traits, but…
The genes for those traits are found on the same parts of chromosomes in everyone

8. Human Genome Project
Major science project that mapped out all of the genes in the human chromosomes
Identified the location of our genes
Completed in 2003

9. Our Genes How many genes do humans have?

10. What do our genes do? Genes determine the traits that we have
We are most familiar with physical traits
So basically our genes determine what we look like
Physical traits are observable characteristics
Things that we can see
examples: hair color, eye color, tongue rolling, ear lobes, hairline

11. Genetic Trait Tree
We are going to be creating a Genetic Trait Tree to examine certain characteristics (traits) within our class
For this activity we will be examining 3 traits
Free or attached ear lobes
Widow’s peak
Tongue rolling

12. Our Genes We have 2 copies of each gene (1 from each parent)
Each gene has 2 or more variations for what we see
We can inherit the same or different variations
examples:
Hair color – brown, black, red, blonde
Tongue rolling – can do it, can’t do it

13. Where do we get our genes from?
½ comes from mother
23 single chromosomes in the egg cell
½ comes from father
23 single chromosomes in sperm cell
When the sperm and egg cells combine they form 1 cell with 46 single chromosomes (23 pairs).
All humans have started as 1 cell just like that

14. Inheritance The characteristics seen in us depend on 2 things.
1. the combination of gene variations we get from our parents
2. how those gene variations interact with each other
The different variations of genes are called alleles
2 basic alleles (gene variations)
Dominant: the trait/characteristic that is always seen if it is present
Recessive: the trait/characteristic that is only seen when the dominant variation is not present

15. Dominant and Recessive Traits
Example of dominant and recessive alleles
A person can have a widow’s peak (dominant) or a straight hairline (recessive)
2 dominant alleles = a person with a widow’s peak
1 dominant and 1 recessive allele = a person with a widow’s peak
2 recessive alleles = a person with a straight hairline

16. Inheritance Terms Homozygous Dominant: 2 dominant genes
Homozygous Recessive: 2 recessive genes
Heterozygous: 1 dominant and 1 recessive gene

17. Predicting Inheritance
Punnett Square: a tool to predict the characteristics a child can inherit from its parents
Use the alleles each parent has to determine the possible gene combinations that can be passed to offspring
Capital letters = dominant allele
Lowercase letters = recessive allele
W = dominant
w = recessive

18. Punnett Square Example
Example using hairline
Mother has the following combination – Ww
Father has the following combination – ww
They each pass 1 gene variation (letter) to their offspring
Draw a Punnett Square
Label sides
Add parent variations
Fill in the square
MOTHER W w
F A T H E R
W w w
w w w
W w
w w

19. Punnett Square Example
What does this show us?
Dominant = widow’s peak
Recessive = straight hairline
Genotype: genetic makeup
2 of 4 children have Ww and 2 have ww
Phenotype: physical appearance
50% chance of having a child with a widow’s peak
50% chance of having a child with straight hairline
MOTHER W w
F A T H E R
W w w
w w w
W w
w w

20. Modern uses of DNA Technology
Selective Breeding
Breeding plants or animals for specific traits
Has been used to create all of the different breeds of dogs that we currently have
Bred to make them better hunters, or nicer temper, or better for protection

21. Modern uses of DNA Technology
Forensic Science
DNA Fingerprinting: identifying people based on their DNA
What shows on TV have you seen that use this? 21

22. Forensic Science Pictures

23. Forensic Science Pictures

24. Modern uses of DNA Technology
Genetic engineering
Changing the DNA of an organism to alter it in some way
Has been used to alter plants and vegetables
Grow bigger, faster, in tougher conditions, and resistant to insects
Transgenic organism: an organism that has had it’s DNA altered by genetic engineering. 24

25. Modern uses of DNA Technology
Gene Therapy
A type of genetic engineering in which damaged genes are replaced by normal genes 25

26. Genetic Engineering Movies26

27. Modern Uses of DNA Technology
Cloning
Creating an exact copy of an existing organism
Dolly (a sheep) was the first cloned animal to survive the process
Happened in 1997
How is it done?
There are problems with it though

28. Cloning

29. Cloning Movies 29

30. Cloning Movies 30

31. Cloning Movies

32. Modern uses of DNA Technology
Stem Cell Research
Taking an undifferentiated cell (one that hasn’t changed into a specific type of cell) and making it turn into the type of cell you want it to
Can be used for:
Creating new organs to replace damaged ones
Replace damaged nerve cells in a spinal cord
Replace damaged brain cells

33. Stem Cells