3/16 Daily Catalyst Pg. 32 DNA Similarities
 1. Why can bacteria evolve just like we can?
 2. Why do bacteria become antibiotic resistant?
 3. In a population, 14% of the population should the dominant
allele. What percent age of the population has the recessive
allele?
1
1
1
2
2
3
2
3
4
4
3
3/16 Daily Catalyst Pg. 32 DNA Similarities
 Evolution test on Thursday




Review day on Wednesday
Study guide due test day
Evolution debate on Friday
Class Point reward on Friday
 Finish Lion King??
3/16 Daily Catalyst Pg. 32 DNA Similarities





Daily Catalyst
Class Business
Finish evolution of bacteria
DNA similarities notes
Comparative embryology project
3/16 Daily Objective
 We will be able to evaluate given data sets that
illustrate evolution as an ongoing process.
 Essential knowledge:
 Populations of organisms continue to evolve
What can we do?
 A strategy being considered for use in hospitals called cycling.
The idea is simple: doctors in a hospital would cycle through
antibiotics, prescribing a particular antibiotic for period of
time and then switching to a new one. Researchers and
clinicians thought that cycling would reduce levels of
antibiotic resistance because the bacteria would not have time
to evolve to keep up with the changing drugs — just as a
resistant strain for Drug #1 evolves and spreads, along comes
Drug #2, and strains resistant to Drug #1 no longer have any
advantage.
 Key Point #4: What is a solution to antibiotic resistance?
What is your opinion?
 Worksheet:
 PBS video clip
 http://www.pbs.org/wgbh/evolution/educators/lessons/less
on6/act1.html
Work time
 Directions: Complete the book work on bacteria
resistance. Your ws is due Wednesday
 Noise: 1 (with partner)
 Time: 10 minutes
3/16 Daily Objective
 Explain how factors affect gene
frequency in a population over time and
the DNA similarities among organisms.
Darwin’s evidence Pg. 26
Fossils
Comparative
anatomy
Biogeography
Classification
DNA
Similarities
 Read page. 262 section titled, Molecular Biology





Answer the following questions:
1.Where does anatomical homology fail?
2.The greater the number of sequence differences, ___________
3. What is homology?
4. How does the concept of homology relate to molecular
biology?
 Key Point #1: DNA is your genetic
information (genes)
 Your DNA determines what is on the inside and the
outside (the traits)
 Genotypes and phenotypes
 Genes and physical expression of genes
 For example:
 predisposition to cancer or eye color
Turn and Talk
Do all cells contain the same DNA?
No, all cells have the same building blocks, but the
building blocks are arranged in different orders to
give us variety.
 Humans and Chimps share the same basic building
blocks like the nucleotides- A,T,G, and C
 Just arranged in different orders
Key Point #2:
The more DNA two organisms share
in common, the more closely related
they are.
Stop and Jot
 Why are homologous structures evidence for
evolution?
 Homologous structures are evidence that homologous
organisms share a common ancestor
Who do we get our DNA from?
If different organisms have similar DNA, then they…
Key Point #3: If two organisms have
homologous structures 
They SHARE A COMMON ANCESTOR!
For example…
 Humans share a large portion of their DNA with other
mammals. This strong correlation is evidence that
humans and other mammals are closely related.
What percentage of DNA does Mrs.
Ireland share with her siblings?
What percentage of DNA does Mrs.
Ireland share with other humans?
What percentage of DNA does Mrs.
Ireland share with other mammals?
What percentage of DNA does Mrs.
Ireland share with other organisms?
What percentage of DNA does Mrs.
Ireland share with plants?
Final thought- Turn and Talk
Why is DNA used as evidence
for evolution?
 DNA is a valid piece of evidence for evolution because we can
use DNA sequencing to determine similarities and differences
between species. DNA can also account for structural similarities
seen in organisms. For species that have a common ancestor and
have recently undergone evolution to form a new species, will
share more DNA with one another.
Practic
e Time!
 Which layers are the same age?
 What type of structure is shown below?
 Which layer is older, A or D?
 What type of structure is shown below?
Why is DNA evidence for evolution?
 We can look at the similarities among species and
determine they must have the same ancestor since
they same building blocks.
Comparative Embrology Project
 Directions: Read the pre-reading and answer the questions.
the Using the hints, complete the DNA similarity project. The
graph needs to be glued into your notebook on Page 33.
 Time: 15 minutes
 Noise: 1 (with partner)
Name
Exit Ticket #7
 1. What is DNA?
 2. If two organisms have little to no DNA similarities,
what can we say about their relation?
 3. Why are homologous structures evidence for
evolution?
 4. Use the diagram to explain the similarity between
Human and Zebras.
Debate





 Rules of the debate:
One side speaks at time
Interrupting one another will lead to the lose of
points
No swearing or offensive terms by ANYONE
The audience may ask questions and comment by
raising their hand
You must include facts and a well written argument