1. Genetics

2. Genetics:
Study of genes and how genes cause characteristics to be passed from parent to offspring.

3. Characteristics:
Characteristic: a trait, ex. Height or color

4. Genes: Genes: a section of DNA that has info for a certain trait.
an area on a chromosome that has directions for how a trait should look
When DNA of a chromosome is copied the trait s copied

5. Alleles: Alleles: different versions of the same gene
Each gene may have several different versions
Gene for height: tall, short
Color gene: yellow, green

6. Gregor Mendel: 1842 became an Austrian Monk
Studied at the University of Vienna
Taught physics and local history
Worked with pea plants to study heredity
Use mathematics to interpret his results
1865 presented his findings to the Brunn Society of Natural History
1900 his findings were determined to be significant

7. Why Pea Plants? Regenerate/grow quickly in a small garden
Produce many seeds
Pollinate easily
Easily manipulated due to their ability to self pollinate

8. Pea Plant Anatomy:

9. Mendel’s Experiments:
He used true breeding strains that self pollinated.
He cross-pollinated his true breeding plants by removing the reproductive parts of the flowers.
He was very methodical and used math and ratios to explain his findings.

10. Dominant allele:
Version of the gene that the organism will look like ________________________________________________________________
Shown by upper case letters
Examples:

11. Recessive allele:
Version of the gene that the organism looks like ________________________________________________________________
Show by two lower case letters:
Example:

12. Example:
T= dominant
t= recessive
Gene=
Tt=
tt=
TT=

13. Genotype: The specific alleles (genes) an organism has
_____________________
____________ Dominant: TT (________________)
Homozygous _____________: tt (_________________________)
__________: Tt (1 upper , 1 lower case)

14. Phenotype:
What the organism actually looks like
TT=
Tt=
tt=

15. Punnett Squares:
A diagram used for ____________________________________________ involved in a genetic cross.
Each side of the square is ______________________________________________ allele combinations.
Each allele _____________ therefore each letter is placed in its own row/column (monohybrid crosses)

16. ______________
___________

17. Mendel’s Crosses: Rr P1 Generation Cross R R r r F1 Generation:
Genotypes:
Phenotypes:

18. Mendel’s Crosses: RR Rr rr F1 Generation Cross r R R r F2 Generation:
Genotypes:
Phenotypes:

19. Mendel’s Crosses: F2 Generation Cross r R r r F3 Generation:
Genotypes:
Phenotypes:

20. Law of Independent Assortment:
During gamete formation, each parents allele combination is distributed randomly to form different gamete combinations.
Use FOIL
YyRr: YR, Yr, yR, yr

21. DiHybrid Crosses:
A punnett square showing the possible gamete combinations for more than one trait
Each trait is represented by a different letter
Genotypic and Phenotypic ratios include both traits

22. Dihybrid Crosses: YR Yr yR yr

23. Incomplete Dominance:
A combination of alleles where the heterozygous genotype has a phenotype that is a mix of the homogeneous phenotypes
Neither of the alleles are the dominant allele.
Example: Rr Rr=red, Rw Rw=white, Rr Rw= pink

24. Incomplete Dominance Example:
P1 Cross:
Cross red with a white:
F1 Generation:
Genotypes: 4: RR Rw
Phenotypes: 4 Pink RR Rw
RR Rw

25. Incomplete Dominance: F1 CrossRR Rw
RR RR
RR Rw RW
RW Rw

26. Co-Dominance:
A combination of alleles where the dominant forms of both are evident when heterozygous.
Example: Blood Type:
Alleles IA, IB, Io (recessive)
IAIA or IA IO: Type A blood
IA IB: Type AB blood
IB IB or IBIO: Type B blood
IOIO: Type O blood

27. Sex Linked Traits:
Traits that are controlled by genes on the X chromosome.
Recessive sex-linked traits are more likely to effect males because of the one x chromosome
Red-Green Colorblindness: recessive x linked trait
Hemophilia: recessive x linked trait