BIOL 2030 Study Guide - Cladistics, Thumb, Nervous Tissue
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Lecture 1 – September 14, 2010
Email: firstname.lastname@example.org T@2-3PM LM205
Tamara Kelly email@example.com by appointment only
Midterm Exam is 75 minutes, 40 MC Balances of material i.e. equal number of questions.
Midterm includes material up to and including Oct. 21st (Mollusca II)
Final is 80MC, 20 from Midterm 1 material and 60MC of post-midterm material
Lecture 2 – September 16, 2010: Classification and Phylogeny (Ch4, 72-88)
Classification and Relationships
Aristotle had an interest in classifying and was the first person to start it
Linnaeus really developed the system to our current model (1700’s)
oBased on morphology – what the animal’s body shape looks like
oHierarchical taxonomic framework: at the top an all encompassing group i.e. Kingdoms,
Phylum, Class, Order, Family, Genus and Species aka “7 mandatory ranks”
oFor larger animal groups you have way more ranks; upto 30 ranks!
oBinomial nomenclature ex. Anguilla japonica (capital first letter for genus and species is the
second work aka species epithet
Phylogeny: Phylon means race and genesis means descent. Basically the history of development of species or
other group. Aka ancestry.
Characters: organismal features used to make evolutionary tree/phylogeny
Homology: character similarity resulting from common ancestry, shared character is because they
have one common ancestor which was held onto while the species evolved
Homoplasy: non-homologous characters which misrepresent common ancestry. Ex. Mammals, birds
and fish are NOT closely related but they all have similar body shapes. Evolutionary convergence of
fusiform shape (body is tapered on both ends) due the environment they live in.
How do we use character variation to reconstruct phylogeny? Cladistics
Cladistics: evaluation of information for tree building and classification.
Cladogram: End result or diagram based on the cladistic analysis, your evolutionary tree. Common
ancestor is at the base of the diagram and species branch off. Can get huge! Clade is group of
organisms that includes most recent common ancestor and all members and descendants of that
Polarity: Basically looks at different forms of a character. Ex some animals have an opposable thumb
while other don’t. Did the common ancestor have the opposable thumb or not? Cladistics is unbiased
because it allows you to ask questions about its ancestry.
oOutgroup comparison: Examines polarity of a character state. Ex. Outgroup is at the bottom
of the clade and you examine say vertebral colomn. The second outgroup may have the vertebral
colomn. Outgroup is basically the closest ancestor that lacks the characteristic you’re
Sources of Phylogenetic info
Comparative morphology: includes the study of the developmetal origin aka embryo. Eg. Skull
bones, limb bones, scales, hairs. Where can you get this information? Fossil records and living species!
Fossil day plays an important role even today.
Comparative biochemistry: gene and protein sequencing sg. mtDNA (mito DNA changes fast), tRNA
(changes slow). This is done mostly from living material but can also done from fossil material.
Comparative cytology: examines chromosomes, number of it, shape and associated material (ex.
Histones). Only from living material.
ANIMAL ARCHITECTURE (Ch3, 55-71)
5 categories of organization:
**Bacterial and Protozoans ARE NOT THE SAME. Protozoans are considered animals NOT bacteria. **
1)Protozoa: unicellular animal-like orgs and animal like looking cells. Can cause diseases like malaria,
shagus disease etc. Free-living single cells.
a.Protoplasmic level of organization : contain specialized organelles like contractile vacuole.
2.5)Metazoa: multicellular animals. Cannot live independently. Ex take a liver cell and it will die on its own.
a.Cellular level of organization: forms aggregate of cells that exhibit division of labor. Like a
colony of protoplasmic cells that make up a whole cell. Cells NEVER form tissue in this case
b.Cell-tissue level of organization: forms tissue
d.Tissue-organ level: aggregation of tissue that forms an organ. Organ made up of more than one
type of tissue ex. Parenchyma and stroma (connective tissue).
e.Organ system level: organs work together as a system to perform common function. Associated
with basic body function.
11 Organ systems observed within metazoans
Which organs work together to form the digestive system? Gastrointestinal (GI) tract!
1)GI tract: oral cavity etc
2)Accessory digestive: salivary glands
Tissue Types (pg. 64)
Tissue: Organization of like cells that make up organs: 4 types:
1)Epithelial tissue (6 types): covers external or internal surface. Ex. Skin. Skin of frogs is
important in science studied to understand transport of salt. Frogs live in fresh water so you should
lose salt to the environment and gain water through osmosis but not in frogs! It’s actively
transporting salts in its skin and responsible for maintaining high salt concentrations.
a.Simple squamous: thin flattenend carpet of cells. Good for gas exchange in lungs.
b.Simple Cuboidal: short boxlike cells. Found in secretory organs eg. Kidney. Good for salt
transport. Absortptive function. Found in insects in malphigian tubules responsible for its
resistance to pesticides due to transporters found in these tubules.
c.Simple columnar: individual cells are tall and associated with absorptive surfaces like
d.Stratified squamous: layered on top of each other. Top most layer looks like a carpet while
bottom of epithelia is basal cells that push upward so outside layer is always being replaced.
Esophagus (food goes down)
e.Stratified columnar: found in rectum, cells on top layer are elongated and bottom is
f. Pseudostratified: single layer of cells but some of them are wide at the top and thin at the
base while others are wide at the base and thin at the top. “Fake” cuz it looks like a thick
layer with bunch of cells but its not like that. These cells can have cilia at the top. Nose etc.
Examples of epithelial tissue
Fish Gill: Simple multifunctional epithelium. Gill Arches contain blood vessels. Involved in respiration. Grabs
CO2 and gets rid of it back to water. Maintains ion balance. Acid-base balance, metabolism causes acid so gills
move proton out to the water. Waste excretion, nitrogenous waste and ammonia so gills contain transporters
that do that. 90% squamous epithelial for pavement cells and 10% cuboidal for chloride cells
2)Connective tissue: diverse group. Specialized to bind and support other tissue. Structural. bone
tissue, vascular system (blood vessels)
3)Muscular tissue: specialized for voluntary and involuntary movement of many organs. Common
tissue type found in all animals. Cardiac, smooth lining esophagus, skeletal for limb movements.
4)Nervous tissue: specialized for reception and conduction of stimuli and impulses. Electrically
active. Brain, spinal chord.
Non cellular Components
1)Body fluids: eumetazoans contain two fluid compartments.
interstitial fluid: fluid that occupied immediate space surrounding cells in tissues and within organs.
2)Extracellular structural elements: supportive material like cuticle etc.
Only a few body plans in the animal kingdom:
1)Asymmetry: lack of symmetry and no axis and no plane of symmetry. Ex. Protozoans like amoeba,
2)Spherical symmetry: rare and found only in “Radiolarian” protozoans. You can cut the animal any
way you want through the core and you will always get two equal halves. Lacks polarity.
a.Radial Symmetry: polyps and some sponges. Divided equally by more than two planes
passing thru the LONGITUDINAL AXIS. Most forms are modified like a starfish which has 5
arms it bcan also be called pentaradial. Best example is Sea anemone
b.Bilateral symmetry: body parts with a head and tail (posterior & anterior). Animal must be
divided at midsaggital plane (plane that separates left and right of the animal). Associated with
cephalization (concentration of nervous tissue to form a sort of brain or ganglion involved with
processing). Controlled mobility because head sees environment first.
c.Spherical symmetry: covered above
Lecture 3 – September 21, 2010
3 levels of character in animal body plans
Body Plans Tree
start with spherical symmetry at the bottom of the tree
radial symmetry slightly above to the left (just below flatworms)