1. Monohybrid Crosses Part 1
Biology
Mrs. Harper
1//18

2. January , 2018 Download notes Begin working on Do Now
Have homework (Article Questions) out on desk

3. Do Now 1//18 What is the definition of heredity?
What is the definition of genetics?
What is a dominant trait?
What is a recessive trait?
Are our genes an exact copy of our parents? Why or why not?
What is the difference between genotype and phenotype?
Why do we often look like our family?

4. Genetics and Heredity! The way we look is directly correlated to the genes of our parents and the mode of inheritance for those genes.
What are some traits Mrs. Harper inherited from her parents?
What are some physical traits you inherited from your own parents?

5. Gregor Mendel Father of genetics Was an Austrian monk
Studied inheritance patterns in pea plants

6. His Experiment Crossed pure yellow peas with pure green peas
Results were all yellow for 1st generation
Then crossed offspring to get ¾ yellow and ¼ green peas for 2nd generation

7. His Discovery: Heritable Traits Called Genes
Alleles- alternate forms of a gene
Some genes are dominant and some are recessive
Dominant- the trait that overpowers another (capital letter)
Recessive- trait that is covered up by the dominant (lower case letter)

8. Practice Practice: Write whether each allele is dominant or recessive.
A - a-
b- B-
h- H-
C- c-
D- d-
F- f-
w- W-
r- R-
Dominant
Recessive
Recessive
Dominant
Recessive
Dominant
Dominant
Recessive
Dominant
Recessive
Dominant
Recessive
Recessive
Dominant
Recessive
Dominant

9. Homozygous vs Heterozygous
Homozygous- two of the same allele, could be dominant (AA) or recessive (aa) (also called Purebred)
Heterozygous- two different alleles (Aa) (also called Hybrid)

10. Practice
Practice: Determine whether the genotype is homozygous dominant, homozygous recessive or heterozygous.
Ss hh-
GG- jj-
Pp RR-
qq Tt-
DD- Bb-
ff YY-
Zz ee-
Homozygous Recessive
Heterozygous
Homozygous Recessive
Homozygous Dominant
Homozygous Dominant
Heterozygous
Homozygous Recessive
Heterozygous
Homozygous Dominant
Heterozygous
Homozygous Recessive
Homozygous Dominant
Heterozygous
Homozygous Recessive

11. Genotype & Phenotype Genotype The genetic makeup
Symbolized with letters
Example: TT, Tt, tt
Phenotype
Physical characteristics
Examples: Short, tall, yellow, green

12. Practice
Practice: Determine the genotype (letters) and phenotype (the way it looks) for each individual.
Heterozygous blue lizard
Genotype- Phenotype-
Homozygous dominant red apple
Homozygous recessive white fur
Heterozygous tongue-roller Bb
Blue RR
Red ww
White Tt
Able to roll tongue

13. Punnett Squares and Crosses
tool used to calculate probability of inheriting certain traits
Monohybrid cross-cross involving just one trait (example: pea color)

14. Assignment
Work on monohybrid crosses part 1 worksheet independently on Code Red
I will pass back tests shortly for you to review your answers.
Unfinished classwork is homework

15. Unit 3 Test Answer Key