Heredity and Genetics Heredity and Genetics

How it all works  Dominant is the expressed trait. (That means the trait we see. So it gets a capital letter.)  Recessive is the unexpressed trait. (That’s the one we don’t see. So it gets a lower case letter.)  Codominant is when both traits are equally dominant and are are equally dominant and are equally expressed.

What is Genetics?  Genetics explains how traits are passed on from generation to generation.  Traits are either Dominant or Recessive  (Look at the Laboratory Investigation sheet)  Tongue Roller-  Ear lobes-  Hair dark/light color-  Widow’s Peak-  Red/not hair-

Who is Mendel and What Does a Pea Plant Have to do with ME?  Mendel became the father of genetics.  He did not realize it then, but his study of pea characteristics or traits gave us the basics for genetics today.  He studied traits like how tall they grew, the color of seeds, and the shape of the seeds.  He tried to cross traits to see what would happen. (He found things like a tall and a short made 4 tall.. This led to the idea of dominant and recessive.

 The Genotype is the “gene” make-up of an organism.  The Phenotype is the “physical  The Phenotype is the “physical” look that the genes created. What is his phenotype and genotype? Brown Hair –BB or Bb Blonde Hair-bb

Pairs- the traits are put is pairs: one from mom and one from pops. The pairs are either ( different Dd ) or (same DD or dd ). Pairs- the traits are put is pairs: one from mom and one from pops. The pairs are either heterozygous ( different Dd ) or homozygous (same DD or dd ). We use the to figure out what an offspring's genotype and phenotype will be. Draw this on your graph paper. We use the punnett square to figure out what an offspring's genotype and phenotype will be. Draw this on your graph paper. d d D d Dddd

Now try this: Gg gg dd DD

Now try this: DdDd DdDd Gg ggGgGggggg dd DD GgGg g

continue Hh hh Ss

continue SSSs Ssss HhHhhhhh Hh hh Ss HhHh h SsSs S s

Genotype and Phenotypes  H is blue, h is yellow: What is Hh?  T is tall, t is short: what is TT? Tt? tt?  What is the only way to make the recessive gene show?

Blonde bb Red BB

AHHHHHHHHH

Word Bank for Heredity Quiz Trait heterozygous allele Allele Genotype Phenotype homozygous allele Dominant allele heredity Recessive allele genetics