Transcript Review - science

Do Now:
• If the world were hit with a massive outbreak of a
disease like Bubonic Plague. What would the
impact be on human?
Homework – Thursday’s class
• Review your tests, make corrections and
be ready to re-take the test tonight at
7:45.in the Biology room. Read pages 338
– 343
• Define these terms:
• Transformation
• Bacteriophage
Review
• Write these questions and be prepared to
answer them:
• Why did Gregor Mendel choose the Pea
to study genetics and what did he find?
– The pea has a simple design.
– Fertilization – Hybrids
– Pollination
– Gametes
Review
• What is heredity:
• The sum of the characteristics and potentialities genetically
derived from one's ancestors
• What are traits?
 The specific characteristic of an organism such as
height, or color
• What is the Law of Segregation?
• Each parent passes along one trait (allele) to the off-spring
• What is the difference between Genotype & Phenotype?
• Genotype = the genetic make up. For example blonde hair
would be bb, meaning two recessive genes.
• Phenotype = actual physical characteristics. In this case
blonde hair.
Review
• Genotype – the genetic makeup of a
gene (TT, Tt, tt)


Homozygous –Same type of
alleles (Tall – Tall= TT) or (shortshort=tt)
Heterozygous – both different
(Tall-short = Tt).
Review
• What is the difference between Homozygous &
Heterozygous?
• Homozygous are genotypes that are the same and either
dominant or recessive, not one of each. For Example –
blonde hair (bb) or Brown hair (BB).
• Heterozygous are genotypes that are both different,
meaning one dominant and one recessive.
• Mendel’s law of Dominance would simply be that
although two different genotypes are present, the
dominant gene would expressive itself. The recessive
would just be passed along without being expressed.
Review
• This is an example of what? (Two
possible answers)
• Inbreeding and / or Genetic Drift
Small gene pool / inbreeding
• Inbreeding and / or Genetic Drift aka the
Founder’s Effect.
• A small isolated community will
naturally have less genetic diversity.
Some random and / or rare conditions
tend to appear more often. For example
the British Royal Family and
hemophilia.
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?
• 9
• How many Brown Hair & short
• 3
• How many Red Hair & Tall
• 3
• How many Red Hair & short
• 1
Review stuff
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•
•
•
What is Co-Dominance?
Both are expressed equally.
Incomplete Dominance?
Neither one is fully expressed, they are blended (meaning neither red
nor white is expressed, but the blending in this case pink.
Dominant vs Recessive
• Hitler’s hope was to have his “super race” by
creating genes that were recessive, which he
considered to be “pure”.
• Explain why he felt that the use of recessive genes
was “pure?”
• Because on the rarity of the traits. Also, once doing
the Di-Hybrid (16 box Punnett Square) there is only
one totally recessive box. That recessive cannot be
altered or in his mind corrupted.
• There is no way to tell if someone with brown hair is
homozygous (BB) or heterozygous (Bb). Very easy to
see Blonde hair - bb
Principle of Dominance
• Principle of Dominance.
• Create a scenario that illustrates the Principle of
Dominance.
• Blue eyed mom (bb) homozygous and brown eyed
dad (you pick either heterozygous (Bb) or
homozygous (BB). Use the punnet square below.
•
Before leaving
Before you leave, clean up
the area around your table.
Make sure you have the
homework(s) for tonight.