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

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

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?

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?

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

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

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)

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

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)

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

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

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

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

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

Unit 3 Test Answer Key