Unformatted text preview: Bio 204 Lab Practical #1 (Labs 1,2,& 3) Lab #1:
● Evolution- modification with descent, changing over time through different
● Descent- generations past, present, and future. “Transfering of genetic material from
parent to offspring”
● Modification- change. “Change in the genetic material from parent to offspring, such
that the genetic material is different form the parents”
● Species- a group of living organisms that are able to inbreed and pass on their
● Natural selection- being able to adapt to different environment and survive. “The
differential contribution of genetic material from genertaion to the next”
● Adaptation- being able to survive by performing a certain function. “A structure or
feature that performs a particular function and which itself brings about increased
survival or reproduction.”
○ Define ‘evolution’, ‘natural selection’, and adaptation carefully. Try defining
them all in one sentence together. You should be able to explain these easily
without much thought.
○ How is the concept of phylogeny related to the concept of taxonomy?
○ The concept of phylogeny is related to the concept of taxonomy by phylogeny
means the study of evolution within a group of organisms. Taxonomy is a
component of systematics that uses description, identification, nomenclature,
and classification to help study living organisms or may be used in any field.
So the two go hand in hand, because we use taxonomy to help us with the
concept of phylogeny.
● *ALL PHYLOGENETIC TERMS*
● Cladogram- a diagram that represents phylogeny, contains an ancestor and
● Speciation- the formation of two species from one common ancestor.
● Common ancestor- two species have evolved from, two or more person claim
● Apomorphy- a new derived feature.
● Synapomorphy- is an apomorphy that unites two or more linages
● Plesiomorphy- the pre-exisiting ancestral state.
● Symplesiomorphy- is also shared with other taxa that have an earlier last common
ancestor with the taxa under consideration.
● Autapomorphy- an apomorphy that occurs within a single lineage. ● Homology- similiarty resulting from common ancestry.
● Homoplasy- a character shared between a set of species but not their common
● Convergence- is the independent evolution of a similar feature in two or more
lineages. “the tendency of unrelated animals and plants to evolve superficially
similar characteristics under similar environmental conditions.”
● Reversal- the loss of a derived feature with the re-establishment of an ancestral
feature. ex) snakes losing their legs
● Monophyletic- consists of a common ancestor and ALL of its descendents
● Paraphyletic- includes the common ancestor but not all of the descendents of that
● Polyphyletic- consists of a taxa whose common ancestor is NOT a member of that
● Outgroup- a group of organisms who do not belong with the group whose
evoultionary relationships are being studied.
● Can you explain how parsimony is used to infer phylogenetic trees?
○ The principle of parsimony is that the cladogram with the fewest
evolutionary steps is the “best” representaion of phylogeny.
● Describe 4 steps by which life on earth evolved from organic compounds
○ 1) Self- replicating RNA functioning as a ctalytic enzyme.
○ 2) The evolution of a membrane surrounding the RNA to form a cell.
○ 3) The evolution of proteins that replaced RNA as the enzyme for chemical
○ 4) The replacing of RNA with genetic material by a more chemically stable
● What are the three domains of life?
○ Bacteria, Archaea, and Eukarya
● Which is the outgroup?
○ Bacteria is the outgroup
● What are some features that Bacteria and Archaea share?
○ Some features that Bacteria and Archaea share are, a cell wall that is lined
with a plasma membrane that encloses cytoplasma, DNA, ribosomes, and
enzymes inside the cell. They do not have a nucleus or organells or a
cytoskeleton, and are mostly unicellular.
● Are these synapomorphies or symplesiomorphies?
○ These are symplesiomorphies.
● Name any synapomorphies shared by Archaea and Eukarya ● ●
● ● ● ● ● ● ○ They have RNA polymerase and ribosome RNAs that are similar to each
What are the 3 standard forms of Bacteria?
○ Cocci (spherical)
○ Bacilli (rod)
○ Spirilloid (spiral)
Which specialized bacteria are filamentous?
○ Cyanobactria and streptococcus
Where are Archaea likely and not likely to be observed, based on the manual?
○ They are likely to be found in extreme weather like very cold, hot, or salty
Compare and contrast the 4 main types of Bacterial/Archaeal metabolism:
○ Hetero vs Auto: hetero require pre-exsisting organic compunds from the
enviroment as their food. Auto make their own food from the co2 in the air.
○ Photo vs Chemo: Photo use sunglight to help them make their energy/food.
Chemo involves the use of organic and inorganic compounds to make their
Understand also saprobe vs. symbionts
○ Saprobe- an organism that lives on a dead or decaying organic matter and
feeds off that.
○ Symbionts- have a host, are surviving/living of a live organism.
Which Bacteria have heterocysts, what is their purpose, and what do they look like?
○ Some Cyanobacteria have heterocysts like Rhizobium. Their purpose is to
convert the N2 in the air to ammonia. They look like a big circle on the
bacteria chain. Almost look like they are filled with water, usally lighter color
than the rest of the chain. They are pretty big in size as well.
Rhizobium serves the same purpose.
○ What structures do they form with land plants?
■ They form a symbiotic mutualistic association with roots of land
plants. They form nodules.
● What do Rhizobium and cyanobacteria have in common?What differs
○ They both have heterocysts that convert N2 to ammonia.
Name all synapomorphies of the Eukarya
○ 1) they contain chromosomes, linear DNA accosited with histone proteins
○ 2) they have a nucleus
○ 3) they go through mitosis and meiosis
○ 4) they contain other organelles like the endoplasmic reticulum.
○ 5) they contain a cytoskeleton ● Some of these synapomorphies are the result of endosymbiosis. Explain this term,
and how the modern Eukaryotic cell came to be.
○ Endosymbiosis means that once a bacterium cell was able to live by surviving
off another living organism but eventually become super dependent on the
organisim it became a part of it. Examples of this are the chloroplast and the
● Define mitosis and meiosis
○ Mitosis- cell multiplication, the cell is the exact replica of the parent cell.
○ Meiosis- cell division where the end product is four daughter cells that vary
in genetic material. Half and Half from each parent cell.
● Compare and contrast these two processes
○ The main difference is that during meiosis crossing over occurs which allows
for genetic variation. Meaning the four daughter cells that are created will
not be identical to their parent cells. They will contain 50/50 of their parents
DNA. Also in mitosis the finishing product is two daughter cells that are
identical and diploid. In meiosis the ending product is four daughter cells
which are not identical and are haploid.
● How many cells and chromosomes result from each?
○ Mitosis: 2 cells, 2n (exact number as parent chromosomes)
○ Meiosis: 4 cells, 1n (half of parent chromosomes)
● What is the point of sex? Why did it evolve, what advantage does it confer?
○ Sex gives of genetic variation. This explains why we do not all look alike. This
also ties in with natural selection when a mutation occurs, and allows us to
adapt and evolve.
● Why do some organisms (e.g. all Bacteria) persist without it?
● Define/sketch the three Eukaryotic reproductive cycles: haplontic, diplontic,
○ Haplontic- having a life cycle in which the main form is haploid, but a diploid
zygote is formed.
○ Diplontic- having a life cycle in which main form is diploid, except for
○ Haplodiplontic- gametes are not the direct result of a meiotic division.
Diploid sporophyte cells undergo meiosis to produce haploid spores. Each
spore goes through mitotic divisions to yield a multicellular, haploid
● Why is “Basal Eukaryotes” in quotes inside your lab manual? ●
● ● ● ●
● ○ “Basal Eukaryotes” are in quotes inside our lab manual because they lack
Why is the Kingdom Protista no longer a valid taxon?
○ Because it does not reflect a real evolutionary history.
What are the two groups of photosynthetic Eukaryotes we have talked about?
○ Dinoflagellates and Euglenids
How are they related to one another (look at the cladogram on p. 28) Although both
photosynthetic, how do their pigments differ?
○ Dinoflagellates and Euglenids are related by they both have two flagellas.
However, Dinoflagellates have chlorophyll a and c and Euglenids contain
chlorophyll a and b.
What is meant by primary vs. secondary endosymbiotic events? (p.29)
○ Secondary endosymbiotic events means that the intact chloroplast or
mitochondria were passed on from cell to cell with evolutionary
Name examples of the Diplomonads and Parabasalids
○ Diplomonads: Giardia
○ Parabasalids: Trichomonas
What Eukaryotic organelle are they missing?
○ The mitochondria
Sketch an Amoebozoan from memory. Compare your drawing with Fig. 3.2 on p. 30.
o Sketch again if you left anything out
○ Pseudopodia- thin extensions of the cytoplasma, used in amoebozoans to
○ Amoeboid movement- The movement of pseudopodia
○ Phagocytosis- engulfing/ breaking down food particles
○ contractile vacuole- fills with water and then burst, helps psuh water our of
Sketch a Euglenid from memory. Compare your drawing with Fig. 3.3 on p. 30. o
Sketch again if you left anything out
○ Flagella- motile organells that contain tubulin
○ Cilia- short flagella
○ Pellicle- extra layer of protein that is kinda looked at as the cell wall.
○ Eyespot- used to ditect light source
○ euglenoid movement- move by flowing, contracting, and expanding.
Sketch a Ciliate from memory. Compare your drawing with Fig. 3.4 on p. 31.
Sketch again if you left anything out ● How does Ciliate movement differ from amoeboid/euglenid movement?
○ They move like a wave like function.
● Sketch a Dinoflagellate from memory. Compare your drawing with Fig. 3.5 on p. 32.
o Sketch again if you left anything out
○ Zooxanthellae- when a dinoflagellate is symbiotic
○ Bioluminescent- emitting a flash or light
○ red tide- toxic blooms that kill fishes
● Understand how these 3 terms have special meanings for Dinoflagellates ...
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