2. Genetics Vocabulary Terms Working Problems Monohybrid Crosses

3. Heredity and Genetics Heredity- the passing of traits (characteristics) from parents to offspring Genetics- the branch of biology that focuses on heredity

4. Gregor Mendel Father of Genetics

5. During his early years at the monastery, Mendel began studying and breeding mice. The bishop was not pleased.

6. Brother Gregor settled on bees...

7. and peas.

8. Mendelian Theory of Heredity (the foundation of genetics) 1.For each inherited character, an individual has two copies- one from each parent 2. There are different versions of genes= alleles For example, the gene for flower color in peas can exist in a “purple” version or a “white” version

9. When a trait has two forms and one trait is expressed over the other, the trait that shows up is DOMINANT. Dominant traits are represented by upper case letters. B - brown

10. When a trait has two forms, the trait that is hidden or masked is RECESSIVE. Recessive traits are represented by the same letters as dominant traits but lower case. b - blue

11. An individual having two like genes for a trait, such as BB or bb, is HOMOZYGOUS. These individuals can also be called pure. HOMO = SAME examples: BB, bb, PP, ww

12. An individual that has two unlike genes for a trait is HETEROZYGOUS. These individuals can also be called hybrid. HETERO = DIFFERENT examples: Tt, Ss, Rr, Ww

13. Modern Terms Genotype- the genetic makeup of an organism (the set of alleles an individual has) Phenotype- the physical appearance of an organism Ex. PP or P p Ex. Purple

14. MONOHYBRID CROSS: shows the possible offspring for one trait Bb x Bb Bb B b BB Bb bb Genotypic Ratio: (BB: Bb: bb) - 1 : 2 : 1 Phenotypic Ratio: (Dom: Rec) 3 brown : 1 white B: Brown b: white

15. BB b B BB Bb BB Bb Cross a HOMOZYGOUS dominant individual with a HETEROZYGOUS one using the same trait as the previous problem. Practice #1!

16. Offspring Genotype: _____% homozygous dominant _____% homozygous recessive _____% heterozygous Offspring Phenotypes: _____% brown _____% white 50 0 100 50 0 What is the GR?What is the PR? 2 : 2 : 04 : 0

17. Practice #2! Cross a HOMOZYGOUS recessive individual with a HETEROZYGOUS one using the same trait as the problem before. bb B b Bb bb What is the GR? What is the PR? 0 : 2 : 2 2 : 2