Transcript New Material

Do Now
• British Royal Family Pedigree
• Explain this chart
Homework
• Due for today – Chapter 14, section 1 pages 392-397
(Human Chromosomes)
• Due Thursday (Wednesday for F Period) - Chapter 14,
section 2 pages 398- 401
Review
• Mendel Realized that he could predict how
plants would turn out through the use of
“Probability.” Not always 100% certain, it
was fairly accurate for guessing the
outcomes (not taking into account mutations
(Progeria for example)
• or outside forces (rain, fire,….)
• Mendel used the Law of Segregation to predict
outcomes.
• He created Punnet Square
New Material
• 1. Explain the Law of Segregation.
• 2. A farmer is frustrated by the fact that he
keeps trying to have boys to maintain the
farm and eventually take over the farm, but
the farmer and his wife keep having girls.
They arrive in your office since you are a
world renowned geneticists. Through the
use of the Law of Segregation, explain to
this couple who is responsible for the
having boys as well as girls in a marriage.
• Create a Monohybrid Punnett Square
New Material
• 3. Explain the Principle of Dominance
• 4. Using the examples below circle the phenotypes.
• 5. Using the examples write out all the homozygous
traits
• 6. Using the examples write out all the heterozygous
traits
• Tall – TT
Brown Hair – BB
• Tall – Tt
Brown Hair – Bb
• Short – tt
Blonde Hair – bb
• Green Eyes – GG
• Green Eyes – Gg
• Blue Eyes – bb
New Material
• Principle of Dominance:
• Some alleles are dominant – meaning
Always expressed
• Some alleles are recessive – meaning
they may express the trait unless
matched with a dominate allele.
• But the recessive allele (traits) will be
passed from parent cell to offspring.
Punnett Squares
• Phenotype – Physical Trait (Tall)
• Genotype – genetic make up (arrangement) (TT
or Tt)
• Punnet Squares – mathematical formula to
determine outcomes.
• 4 Box vs. 16 Boxes
• 4 Box means that we are dealing with one
trait. Known as monohybrid (hybrid means a
use of two different things)
• 16 Boxes means it is dealing with two
different traits (hair color & eye color for
example)
New material
• Below is monohybrid – why?
• Only one trait - Tall
New material
• Only one trait – Height (Tt X tt)
• Work it out the probabilities
T
• t
• t
t
New material
• Only one trait – Height (Tt X Tt )
• What are the possible outcomes?
• If these parents had four kids, how many would be
short?
Review
• Mendel used the Law of Segregation to
predict outcomes.
• For example parents with the traits of T=
Tall, t= Short, so if two parents had kids
we would expect that of there is a 25%
chance of having a short child. Often
predicted that 1 and 4 chance of having a
short child, but is that true? Explain
New Material
Now do a Punnet Square – Mom’s traits (tt) & dad’s traits (tt).
Can only do one trait at a time. In this case mom is short and
dad is short (both parents are Homozygous).
Dihybrid
Di-hybrid – deals with two traits. (p. 316) – each box will have 4
alleles = BbTt X BbTt. B- Brown Hair, b – Red Hair, T – Tall, t –
Short
Dihybrid
Do the following - BbTt X BbTt. B- Brown Hair, b – Red Hair, T –
Tall, t – Short
•
BT
bT
Bt
bt
• BT
• bT
• Bt
• bt
Ratios
• How many Brown Hair and Tall will you
have?
• How many Brown Hair & short
• How many Red Hair & Tall
• How many Red Hair & short
The Master Race
Explain Hitler’s “Master Race”
Blonde Hair & Blue Eyes.
• Blonde hair – Is it dominant or a recessive trait?
• Answer – Recessive (BB or Bb would be
dominant).
• Blue eyes - Is it dominant or a recessive trait?
• Answer – Recessive (GG or Gg would be
dominant).
• Are they heterozygous or Homozygous?
• Why is this considered to be more pure?
• Because it can only be Blonde & Blue eyes because
bbgg (Homozygous), unlike BB/Bb & GG/Gg
(which could be homozygous or heterozygous)
Hitler’s Master Race
Explain Hitler’s “Master Race”
• How would you set up a Punnett Square for this
meaning what are the phenotypes and genotypes?
• Phenotypes – Blonde Hair & Blue Eyes
• Genotypes – bb (Blonde Hair) & gg (Blue Eyes)
for Mom and the same for dad:
• bbgg & bbgg
Do the following
Create the genotype formula for Hitler’s Master Race
For the Master Race
Do the following – Blonde Hair & Blues eyes mom & dad
bbgg for mom and bbgg for dad . No dominants
bg
bg
bg
bg
• bg
• bg
• bg
• bg
Do the following
Do the following - BbGg X BbGg. B- Brown Hair, b – blonde hair, G
– green eyes, g – blue eyes
Do the following
Do the following - BbGg X BbGg. B- Brown Hair, b – blonde hair, G
– green eyes, g – blue eyes
BG
bG
Bg
bg
BBGG
BG
bG
Bg
bg
Bb
BbGG
BBGg
BbGg
Review
Henry VIII wants a boy. With the use of the Punnett Square
his chances of getting a boy or a girl. Use the appropriate
genotypes for male / female.