Relationships and Biodiversity

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Transcript Relationships and Biodiversity

Relationships and Biodiversity
State Lab (Pg 131-146; you turn in 141-146)
Relationships and Biodiversity
State Lab (Pg 131-147)
Plants
No seeds
seeds
Gymnosperms
Angiosperms
(naked seed; pine,
spruce, fir, etc…)
(vessel seed (protective
chamber); flowering plants)
Relationships and Biodiversity
State Lab (Pg 131-147)
Relationships and Biodiversity
State Lab (Pg 131-147)
dicots monocots
Angiosperms diverged into
monocots and dicots
Relationships and Biodiversity
State Lab
Angiosperms: Monocots vs. Dicots
Relationships and Biodiversity
State Lab
PLANT VASCULAR TISSUE - tissues that conduct food and water
(phloem and xylem)
Relationships and Biodiversity
State Lab
Curol
Curol is a mitotic inhibitor used in cancer chemotherapy. It was discovered in a National
Cancer Institute program at the Research Triangle Institute in 1967 when Monroe E.
Curoli and Mansukh C. Cancurcere isolated it from the leaves of the tree Botanus
curus.
Relationships and Biodiversity
State Lab
Curol
Curol prevents polymerization of microtubules,
which would kill cancer cell because…
Relationships and Biodiversity
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Microtubles (in yellow) are critical in cell division.
Relationships and Biodiversity
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Curol
Problem: Botanus curus is an endangered
species and we cannot synthesize curol in
a lab yet.
What do we do?
Botanus curus
Relationships and Biodiversity
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Are there other species related to Botanus curus that
also produce Curol?
Scientists have found three candidates:
Species X – Botanus dienerhlus
Species Y – Botanus lolevinus
Species Z – Botanus liuginus
Your goal is to gather evidence to try and determine
which species might also produce Curol.
What evidence might you gather?
Relationships and Biodiversity
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Are there other species related to Botanus curus that
also produce Curol?
Scientists have found three candidates:
Species X – Botanus Dienerhlus
Species Y – Botanus Lolevinus
Species Z – Botanus Liuginus
Your goal:
1. Gather structural and molecular evidence to determine which
plant species is most closely related to Botanus curus and therefore
may also produce Curol.
Relationships and Biodiversity
State Lab
1. You will be separated into 7 groups of 2 or 3.
2. Each group will begin at one of the 7 stations.
3. There will be a rotation every 7 minutes.
Relationships and Biodiversity
State Lab
Stations 1 and 2 - Structural Evidence
Station 1 - Structural Characteristics of plant
Compare the structural characteristics of the plant
samples. Record your observations in Table 1.
Station 2 - Structural Characteristics of Seeds
Compare the structural characteristics of the seed
samples. Record your observations in Table 1.
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Station 3 - Microscope Internal Structure of Stems
1. There are four microscopes.
2. Each microscope has a cross section of one of the
species (Botanus curus, species X, Y, and Z).
3. Use the low magnification. Compare the arrangement
of the bundles (circular or scattered) and record you
observations using words or diagrams in Table 1.
Relationships and Biodiversity
State Lab
Remember Paper chromatography?
What famous individual used this technique and for what did
Chargaff, the A,T,C,G ratios of DNA from
this person use it to observe? Erwin
different organisms
- Analytical technique for separating and identifying mixtures
that are or can be colored, especially pigments.
Relationships and Biodiversity
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How does Paper chromatography work?
The solvent (water in this case) will wick (travel) up the paper. The solvent will eventually make
its way to the sample absorbed on the paper. The molecules in the sample will have a different
affinity for both the paper and the solvent. If the affinity is high for the solvent, the molecule will
move quickly up the paper with the solvent. If the molecule has a high affinity for the paper, it
will resist movement and only move slowly up the paper.
Relationships and Biodiversity
State Lab
Station 4 - Paper Chromatography to Separate Plant Pigments
- The leaves of Botanus curus, species X, species Y and species Z
have been crushed up for you and an ethanol extraction was performed
to pull out the partially hydrophobic pigments.
What should you do with the pigment extract?
You should run them each on paper chromatography to separate
the pigments and compare the different species. The species most
similar to B. curus would be expected to have similar pigment
molecules since pigments are made by enzymatic reactions and
therefore the species would have similar enzymes…
Relationships and Biodiversity
State Lab
Station 4 - Paper Chromatography to Separate Plant Pigments
1. Take four strips of chromatography paper and try to straighten them the
best you can by curling them in the opposite direction and putting a slight
crease down the center (see example setup on the bench).
2. Draw a line 2 cm from the bottom of each of the four chromatography
papers. Use a pencil to label the top edge of the chromatography paper either
Bc (Botanus curus), X, Y, or Z (look at Figure 2 in the lab manual).
Relationships and Biodiversity
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Station 4 - Paper Chromatography to Separate Plant Pigments
3. Add about 1cm of water to each beaker.
4. Place two drops of plant extract from Botanus curus just above the
pencil line as shown in Figure 2.
5. Place the paper into the water and allow the water to move up the
paper. Repeat steps 4 and 5 for the other samples.
Pigment Sample MUST BE above the water level
or the pigment will just diffuse into the water!!!!!!
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Station 4 - Paper Chromatography to Separate Plant Pigments
DO NOT contaminate the samples!!
Label with your name and staple the four pieces of chromatography paper
to the lab when you turn it in.
GOGGLES
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State Lab
Station 5 - Indicator Tests for Enzyme M
Enzyme M is an enzyme
in Botanus curus that is
part of the Curol
biosynthetic pathway.
Relationships and Biodiversity
State Lab
Station 5 - Indicator Tests for Enzyme M
- It is not possible to test a plant directly for Curol (concentration
is too low).
- However, if enzyme M, an enzyme known to be a part of the
Curol synthesis pathway, is present, the plant may produce
Curol.
Relationships and Biodiversity
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Station 5 - Indicator Tests for Enzyme M
- Test the plant extract of each species for enzyme M by adding 5
drops of each extract to the substrate for enzyme M.
The product of enzyme M is a non-hazardous gas and
therefore bubbling indicates that enzyme M is present.
- Record the results in Table 1.
DO NOT contaminate the samples!!
GOGGLES
Relationships and Biodiversity
State Lab
Station 6 – Restriction fragment
analysis using Gel Electrophoresis
Use restriction fragment length analysis to
determine relatedness between the
different species.
The species that is more closely related to B. curus should have more
similar restriction sites in its DNA and therefore will produce similar length
fragments when run on a gel.
Relationships and Biodiversity
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Station 6 – Restriction fragment
analysis using Gel Electrophoresis
A. Use the colored DNA sequence strips,
which represent the DNA of each species
B. Do a restriction fragment analysis using
a restriction enzyme (scissors) that cut at
CCGG.
1. Cut all CCGG sites
2. Run a simulated gel electrophoresis using Table 2.
Draw a line indicating the size of the band on Table 2.
3. Attach fragments to the lab when you turn it in.
Chapter 12 - DNA Technology and the Human Genome
How can we use bacteria to manipulate DNA and protein?
Recall how a bacterium defends itself when a
bacteriophage injects its DNA into a bacterium…
The bacterium has enzymes called restriction
enzymes that attempt to cut up the bacteriophage
DNA before it can take over the cell. Different
species have different restriction enzymes…
Aside: Why do these enzymes not cut the bacterial chromosome?
The bacterial chromosome is methylated (modified by adding –
CH3 groups so the enzymes can’t bind to it)
Chapter 12 - DNA Technology and the Human Genome
How can we use bacteria to manipulate DNA and protein?
Restriction enzymes
1. molecular DNA scissors (enzymes that cut DNA)
2. Different restriction enzymes cut different sequences.
3. Scientists have isolated hundreds of different restriction
enzymes from many different bacteria – EcoRI, BamHI, NcoI,
etc…
Chapter 12 - DNA Technology and the Human Genome
How can we use bacteria to manipulate DNA and protein?
Restriction enzymes
Ex. EcoRI
Notice anything interesting about this sequence?
- It is palindromic, read the same way forward and backward.
- Majority of restriction sites are palindromic…
Fig. 12.4
Chapter 12 - DNA Technology and the Human Genome
How can we use bacteria to manipulate DNA and protein?
Restriction enzymes
Ex. EcoRI
EcoRI
Notice that is doesn’t cut straight through like paper scissors. The enzyme cuts
each strand after the G nucleotide generating single-strand regions called sticky
Chapter 12 - DNA Technology and the Human Genome
How can we use bacteria to manipulate DNA and protein?
Restriction enzymes
restriction enzymes
Chapter 12 - DNA Technology and the Human Genome
AIM: What are some other tools of DNA technology?
Gel Electrophoresis
This technique allows one to not only indirectly view the DNA,
but also to separate and view the DNA fragments.
Fig. 12.10
Chapter 12 - DNA Technology and the Human Genome
AIM: What are some other tools of DNA technology?
Gel Electrophoresis
Gel (like jell-o)
The gel is made of either agarose or polyacrylamide. It has
tiny, microscopic pores that DNA can fit through.
Fig. 12.10
Chapter 12 - DNA Technology and the Human Genome
AIM: What are some other tools of DNA technology?
Gel Electrophoresis
Gel (like jell-o)
The DNA sample is loaded in the wells at the top of the gel.
One sample per well.
Fig. 12.10
Chapter 12 - DNA Technology and the Human Genome
AIM: What are some other tools of DNA technology?
Gel Electrophoresis
Electricity (electrons
flow from top of gel by the
samples to the bottom of
the gel)
Electricity is then run through the gel. Why do you think the
negative end is on the sample side and the positive end is on
the other end
gel?because the phosphates are negative. The
DNAofis the
negative
Fig. 12.10 negative electrons move down and push (repel) the DNA down
Chapter 12 - DNA Technology and the Human Genome
AIM: What are some other tools of DNA technology?
Gel Electrophoresis
Which will move faster through the micro-porous gel, the
longer DNA fragments or the shorter DNA fragments?
The small fragments (fewer nucleotides) will move more easily through the gel and
hence go faster than the large ones.
Chapter 12 - DNA Technology and the Human Genome
AIM: What are some other tools of DNA technology?
Gel Electrophoresis
The gel is soaked with a a compound called ethidium bromide,
which sticks to DNA and lights up when you hit the gel with UV
light…
Fig. 12.10
Relationships and Biodiversity
State Lab
Station 7 – Transcribe and Translate the DNA of each
organism to determine if an enzyme in species X, Y and Z
has a similar amino acid sequence indicating a close
relationship.
What can you say about the amino acid
sequence of the same protein in two
different species if they have a recent
common ancestor?
Chapter 13 – How Populations Evolve
AIM: What evidence do we have for evolution?
8
Number of different amino acids
in hemoglobin.
125
The more recent the common ancestor, the more similar the
amino acid sequence should be since the DNA should be more
Relationships and Biodiversity
State Lab
Station 7 – Transcribe and Translate the DNA of each
organism to determine if an enzyme in species X, Y and Z
has a similar amino acid sequence indicating a close
relationship.
The sequence shown in the lab that
you need to transcribe is the noncoding/anti-sense/template strand.