DNA
At the completion of this unit, students will be able to:
A. Identify the scientists who discovered the DNA
structure
B. Model and label the basic structure of DNA
C. Describe the process of DNA replication
D. Describe the steps of translation and
transcription in changing DNA into traits
E. Describe the effect of DNA mutations and list
genetic diseases that would result
F. Debate the use of genetic technologies in
agriculture
A.
Identify the scientists who discovered the DNA structure
Discovery of DNA
• WATSON and
CRICK
• In 1953
• At Cambridge
University in
England
B. Model and label the basic structure of DNA
DNA Structure
Deoxyribo
Nucleic
Acid
The hereditary molecule
controlling the activities of the
cell
B. Model and label the basic structure of DNA
DNA Structure
Ladder Rungs:
Nitrogenous Bases
Side of Ladder:
Sugar Phosphate
Backbone
(A Spiral ladder)
B. Model and label the basic structure of DNA
DNA Structure
•Sugar Phosphate
Backbone
•Nitrogenous Base
•Base Pair
B. Model and label the basic structure of DNA
DNA Structure
4 Nitrogenous Bases:
(A) Adenine
(T) Thymine
(G) Guanine
(C) Cytosine
ALWAYS
Pair
ALWAYS
Pair
B. Model and label the basic structure of DNA
Are you with me??
Which of the following has the correct
base pair matches?
A. A T C C G T
T C G G C C
B. T T C G G A
A C G C C T
C. T C G C G A
A G C G C T
D. C G T A T C
G C AAA G
B. Model and label the basic structure of DNA
DNA Structure
How do the base
pairs connect?
Hydrogen Bond
Video Clip
B. Model and label the basic structure of DNA
Are you with me?
Which of the following lists the
scientists, year, and university where
DNA was discovered?
A.
B.
C.
D.
Charles Darwin, 1950, Yale University
Watson & Crick, 1954, Cambridge University
Charles Darwin, 1940, Staffordshire University
Watson & Crick, 1953, Cambridge University
Are you with me?
Where is DNA located?
A. Inside EVERY cell nucleus, coiled in the
chromosomes
B. Inside only the nucleus of sex cells, coiled in the
chromosomes
C. Inside the cell, attached to ribosomes
D. Inside the cell, attached to the golgi apparatus
B. Model and label the basic structure of DNA
DNA Structure
Where EXACTLY is DNA located?
B. Model and label the basic structure of DNA
Model DNA
You need:
•2 licorice
•10 toothpicks
•20 marshmallows
(5 of each color)
1-Get supplies
2- Model DNA according to your worksheet
3-Check off with teacher
•A=Pink
•T=Green
•C=Orange
•G=Yellow
B. Model and label the basic structure of DNA
DNA Extraction
C. Describe the process of DNA replication
DNA Replication
Why would DNA need to
be replicated?
C. Describe the process of DNA replication
DNA Replication
What is DNA Replication?
Making an exact copy of a
DNA molecule
C. Describe the process of DNA replication
DNA Replication
Step #2:
New DNA strand
attaches
Step #1:
Hydrogen Bonds
separate base
pairs
Step #3:
2 identical DNA
strands are
formed
C. Describe the process of DNA replication
Are you with me?
During replication, what ensures
that both DNA molecules are
EXACTLY the same?
A. Sugar phosphate backbone is
created the same
B. Phosphate bases are dissolve
during mitosis
C. Base pairs always match. (A’s with
T’s & C’s with G’s)
D. They aren’t the same, this is how
genetic variation is achieved from
parent to offspring.
C. Describe the process of DNA replication
DNA Replication
Bracelet
In teams of 2…
•
•
•
•
•
•
•
Choose 18 random beads of 4 colors.
The beads represent bases, so choose which color of beads will
represent which base. Write the key on your lab sheet.
•
EX – A=Yellow, T=Black, G=White, C= Red
Slide the beads (bases) onto the pipe cleaner in random order.
Select a different pipe cleaner.
Select 18 more beads based to MATCH the pattern you created
with your first strand.
Twist the pipe cleaners together to create the DNA double helix
structure.
Turn the double helix into a circle creating
1 bracelet.
C. Describe the process of DNA replication
DNA Replication
Bracelet
Now copy your DNA bracelet…
•
•
•
•
Untwist your DNA Bracelet
Get 2 more pipe cleaners
Create a copy for each side of the bracelet (RNA)
Twist the bracelets together so you have 2 exact copies
D. Describe the steps of translation and transcription in
changing DNA into traits
So…
How does a DNA
strand become a
trait??
Red Coat
Blue Eyes
Brown Hair
BIG
Small
D. Describe the steps of translation and transcription in
changing DNA into traits
Transcription
• The process of
CHANGING the DNA
pattern into messenger
RNA
• mRNA does NOT have
Thiamine.
• (U) Uracil is used
instead
• In Nucleus
• Video
C. Describe the process of DNA replication
DNA vs RNA
DNA
RNA
•Double
Stranded
•Ladder shaped
•Coiled
•Single
stranded helix
•Has Uracil
base instead of
Thiamine
•2 Kinds
(mRNA, tRNA)
D. Describe the steps of translation and transcription in
changing DNA into traits
mRNA
• Takes coded information
from nucleus DNA to
the ribosomes
• Remember…
Ribosomes=protein factories
D. Describe the steps of translation and transcription in
changing DNA into traits
Translation
• Changes mRNA into specific
proteins in the ribosome
• Video
D. Describe the steps of translation and transcription in
changing DNA into traits
Codon
• 3 bases of mRNA
• Determine order of amino acids
D. Describe the steps of translation and transcription in
changing DNA into traits
tRNA
• Carries amino acids to ribosomes to
pair with mRNA
• Remember: Amino Acids build proteins
D. Describe the steps of translation and transcription in
changing DNA into traits
DNA
Trait
In Nucleus
In Nucleus
DNA
Transcribes
Message to ribosomes
mRNA
mRNA changed to:
Proteins
Translation
At ribosomes
tRNA
Carries amino acids to
match with mRNA:
Produce
Traits
Video
D. Describe the steps of translation and transcription in
changing DNA into traits
Protein=Traits
• Protein• Determine skin color or coat color
• Protein-Insulin
• Lack of insulin=Diabetes
E. Describe the effect of DNA mutations and list genetic diseases that
would result
DNA Mutations
• When a problem exists in the DNA
pattern
• Causes:
o Improper replication
o Environmental damage to DNA
 sun exposure, drugs, alcohol, tobacco, pollution
E. Describe the effect of DNA mutations and list genetic diseases that
would result
DNA Mutations
• Types of mutations:
• Point Mutation: 1 letter changes
•
•
The fat cat ate the wee rat
The fat hat ate the wee rat
• Deletion: 1 codon or letter is deleted
•
•
The fat cat ate the wee rat
The fat ate the wee rat
• Insertion: 1 codon or letter is added
•
•
The fat cat ate the wee rat
The fat cat xlw ate the wee rat
E. Describe the effect of DNA mutations and list genetic diseases that
would result
DNA Mutations
• Human Diseases:
• Sickle Cell Anemia
• Developed as a result of a
medication for malaria in Africa
• Hemophilia
• Mutation of f8 or f9 gene
• Protein for coagulation is not
produced
E. Describe the effect of DNA mutations and list genetic diseases that
would result
DNA Mutations
• Fainting Goats
E. Describe the effect of DNA mutations and list genetic diseases that
would result
DNA Mutations
• Fuzzy Lop Rabbits
E. Describe the effect of DNA mutations and list genetic diseases that
would result
DNA Mutations
• Spider Lamb
Because the
syndrome is a
recessive
genetic disorder,
a lamb is only
afflicted if both
parents pass on
the mutation.
So, it is critical to
identify carriers
of the mutation
F. Debate the use of genetic technologies in agriculture
Genetic Technology in
Agriculture
• Transgenic= A plant or
animal that contains a gene(s)
from another plant or animal.
F. Debate the use of genetic technologies in agriculture
Genetic Technology in
Agriculture
• Golden Rice
• Fortified with Beta Carotene & Vitamin A
• Prevents anemia
F. Debate the use of genetic technologies in agriculture
Genetic Technology in
Agriculture
• Glow Fish
F. Debate the use of genetic technologies in agriculture
Genetic Technology in
Agriculture
• Glowing Plant
• Has gene from
firefly
F. Debate the use of genetic technologies in agriculture
Genetic Technology in
Agriculture
• Round up Ready Corn
Bell Quiz:
Tell me everything you know about
DNA
What does it look like?
Where is it?
What is it’s purpose?
Etc….
Bell Quiz:
1. Name all 4 nitrogenous bases
2. What type of bond connects 2 base
pairs in DNA?
3. Name the scientists that discovered
the double helix model of DNA
4. What year was DNA discovered?
5. What are the sides of the DNA
ladder made out of?
Bell Quiz:
1- What is translation?
2- What is transcription?
3- What is the difference between
DNA and RNA?
4- Adenine pairs with__________
5- Cytosine pairs with__________.
Bell Quiz:
1.
2.
3.
4.
5.
What is a codon?
How does DNA become a trait?
What is translation? Where does it take
place?
What is transcription? Where does it take
place?
Translate the following DNA strand into
RNA:
AT C GAT C C G
Review
1- Who is Watson & Crick? What did they
discover?
2- What is DNA? Where is it found? What
does it stand for?
3-What makes up DNA? What does it look
like?
4-What would be the complement DNA strand
to the following:
ATTCGGCTA
5-What would a complement RNA strand look
like for the following:
ACGAAGCAA
Review:
1- What is a codon?
2-What is the difference between the DNA of
a mouse and a cat?
3-What do ribosomes do?
4-Where is DNA found?
Transcription
Translation