DO NOW

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DO NOW

• Today is binder clean out day!
• Remove EVERYTHING from your binder EXCEPT
• Ch 3 study guide
• Ch 4 study guide
• Assessments that you havent checked on genesis

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1. How is eye color inherited?

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Multiple Alleles

• Sometimes, some traits are inherited by many
  genes working together.
• Examples
• hair color, eye color, skin color

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1. How many possible alleles are there when a trait
   is inherited by simple dominance?
2. How many possible phenotypes are there when a
   trait is inherited by simple dominance?
3. How many possible genotypes are there when a
   trait is inherited by simple dominance?

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Simple Dominance

• 1 allele is dominant and the other is recessive
• 2 possible phenotypes freckles or no freckles
• 3 possible genotypes AA, Aa, or aa

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• What did Mendel conclude about how traits are
  passed from parents to offspring?
• What did Mendel conclude about traits appearing
  between different generations?
• 7. What did Mendel discover about recessive
  traits?

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• Mendels Conclusions

• He found that one trait always showed up and the
  other trait disappeared.
• He called them
• Dominant The trait that always appears (purple).
  Shown as an upper case letter -P
• Recessive - The trait that always disappears
  (white). Shown as a lower case letter p )

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8. What is it called when one plant pollinates
another plant?
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Pea Plants Create Offspring By

1. Self-Pollination pollen (male part) from one
   flower can fertilize the ovule (female part) of
   the SAME flower.

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Pea Plants Create Offspring By

• 2. Cross-Pollination pollen (male parts) from
  one plant can fertilizes the ovule (female parts)
  of a flower on a DIFFERENT plant.

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9. Explain the difference between phenotype and
genotype
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Vocab Review

• Genotype the actual genes (GG, Gg, or gg)
• Phenotype the physical appearance

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10. Create a Punnett Square for a cross between
Gg green plant and gg yellow plant when color is
inherited by simple dominance.
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Steps in doing a Simple Dominance Punnett Square

• Step 1 Identify the alleles

Example What are the possible offspring of a
cross between a heterozygous green plant and a
homozygous recessive yellow plant?
Homozygous dominant Gg parent Homozygous
recessive gg parent
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Steps in doing a Punnett Square
Step 2 Draw a square with 4 boxes
Example What are the possible offspring of a
cross between a heterozygous green plant and a
homozygous recessive yellow plant?


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Steps in doing a Punnett Square
Step 3 Put the alleles from one parent on the
top of the box the alleles from the other
parent on the side of the box
gg parent Gg parent
G
g


g
g
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Steps in doing a Punnett Square
Step 4 Cross multiply to find the genotypes of
the children
G
g


G
g
g
g
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Steps in doing a Punnett Square
Step 4 Cross multiply to find the genotypes of
the children
G
g


G
g
g
g
g
G
g
g
g
g
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Steps in doing a Punnett Square
Step 5 Write the phenotypes of each child in
the boxes
G
g


G
g
g
g
g
Green
yellow
G
g
g
g
g
Green
yellow
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Steps in doing a Punnett Square
Step 6 Calculate genotypic and phenotypic
ratios of the offspring
G
g
List all Genotypes GG Gg gg List
all Phenotypes green yellow


g
g
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Steps in doing a Punnett Square
Step 6 Calculate genotypic and phenotypic
ratios of the offspring
G
g
Count how many of each Genotypes GG
Gg gg Phenotypes green yellow


0/4 0 2/4 50 2/4 50
g
g
2/4 50 2/4 50
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1. How many possible alleles are there when a trait
   is inherited by incomplete dominance?
2. How many possible phenotypes are there when a
   trait is inherited by incomplete dominance?
3. How many possible genotypes are there when a
   trait is inherited by incomplete dominance?

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Incomplete Dominance

• Sometimes there are two dominant alleles and no
  recessive alleles.
• This means that one trait is not completely
  dominant over the other. Both are dominant!
• Ex flower color

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So, when a trait is inherited by incomplete
dominance, there are ____ possible phenotypes
and ____ possible genotypes.
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Red White Pink
3
RR WW RW
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14. Create a Punnett Square for a cross between
RW pink flower and WW white flower when color is
inherited by incomplete dominance.
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What if you cross a PINK (RW) flower with a WHITE
(WW) flower?
R
W


RW
W
WW
RW
WW
W
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What color are the offspring?
R
w
RR 0 RW 50 WW 50 Red 0 White
50 Pink 50


RW
WW
W
pink
white
RW
WW
W
pink
white
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1. How is blood type inherited?  
2. What are the possible genotypes of a person with
   blood type A?
3. What is the phenotype of a person with the blood
   genotype BO?

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How is blood type inherited?

• Co dominance - When 2 alleles are equally
  dominant.
• Example Blood Type
• 2 Dominant alleles A B
• 1 recessive allele O

Geno-type Pheno-type
AA A
AO A
BB B
BO B
AB AB
OO O
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18. DNA is made up of smaller segments called

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• DNA is made up of smaller segments called genes.

No, not that GENE.
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19. Genes carry the code for making
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How genes work

• Genes carry the code for making specific proteins
  (they do not do the work themselves).

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20. What do proteins do?   21. What
are proteins made up of?
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Proteins

• Create traits
• Build body parts
• Create enzymes
• Create hormones
• Are made of chains of amino acids

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22. If a cell has 22 adenine, how much of it
will be thymine?
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Erwin Chargraff discovered that the amount of
adenine (A) is always equal the amount of thymine
(T), AND the amount of cytosine (C) is always
equal the amount of guanine (G).

• He concluded that a rung can either have A and T
  OR it can have C and G but no other combinations
  are possible.

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1. What are the 3 parts of a nucleotide?  
2. What is the process in which DNA makes an exact
   copy of itself called?

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What is a nucleotide?

• A nucleotide is a small piece of DNA which
  contains
• 1 base
• 1 sugar
• 1 phosphate

Lots of nucleotides connect to form a large DNA
molecule.
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26. What are the 3 steps of DNA replication?
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Steps of DNA Replication

• When it is time to replicate, the DNA unzips (at
  the hydrogen bonds).
• New complementary nucleotides move in to match
  BOTH halves of the DNA and form hydrogen bonds
  with the old nucleotides.
• The finished product is 2 identical
• DNA molecules!

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1. What is it called when DNA replication or
   transcription makes a mistake?  
2. What are the 3 types of mutations?

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• When DNA replication or transcription, makes a
  mistake, a mutation occurs.
• There are 3 types of mutation
• Deletion - one pair of bases is removed.
• Insertion- one pair of bases is added.
• Substitution - one pair of bases is replaced with
  another pair

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A mistake in replication or transcription caused
by a mutagen (UV radiation, xrays, cigarette
smoke, etc)

• 29. What causes a mutation?

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30. What is the process in which a gene is
copied? 31. What is the process in which a copy
of a gene is fed through a ribosome and a protein
is made?
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How to Make a Protein?
Transcription the gene for the protein that it
wants is copied (called mRNA) in the nucleus so
that the original DNA never has to leave the
nucleus. The copy then goes to the ribosome.
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Translation After the mRNA is made, it goes to
the ribosome where proteins are made by
connecting amino acids.
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32. What are the differences between mRNA and
DNA?
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Differences between mRNA DNA
DNA mRNA
Longer shorter
Thousands/millions of genes 1 gene
Double stranded (helix) Single stranded (helix)
Bases - ATGC Bases AGCU (U Uracil)
Stays in the nucleus Goes from nucleus to cytoplasm and ribosome
Produced in DNA Replication Produced in Transcription
Deoxyribose Sugar Ribose Sugar
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33. What are 3 letters on mRNA called?
  34. What do the 3 letters on mRNA
get translated into?
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mRNA strands are broken down into smaller
sections of 3 bases calledcodons. Codons 3
letters on mRNA

• The combination of the 3 letters on a codon calls
  for a specific amino acid.