Phylogenetic Trees
What is an outgroup?
Outgroup is a more distantly related group, used as a reference point to observe the most ancestral traits
According to the _____, the main criterion for identifying species is reproductive isolation.
Biological species concept
What are the two types of reproduction that organisms could be capable of?
Sexual reproduction and asexual reproduction
What type of replication do prokaryotes do?
Asexual -- binary fission
When speciation is caused by a geographic barrier it is what kind of speciation?
Allopatric speciation
What is a synapomorphy?
Bonus: Draw it on the phylogenetic tree
A trait common in a single monophyletic group
What is a weakness of the morphological species concept?
It is subjective -- how different is different enough?
Cannot identify species that differ in non morphological traits
Some species are polymorphic
Explain how plants and animals acquire and use energy and their carbon source.
Plants: energy source = sun, carbon source= CO2, nutritional mode = autotroph
Animals: energy source = organics, carbon source = organics, nutritional mode = heterotroph
Compare and contrast the structure of prokaryotes and eukaryotes
They both have a cell membrane, ribosome, chromosome
Prokaryotes: one circular chromosome, no nucleus, yes accessory plasmids. No membrane bound organelles
Eukaryotes: multiple linear chromsomes, nucleus, no accessory plasmids. Membrane bound organelles
What nutritional mode would an organism have that gets its energy from sunlight and its carbon from ingesting other organisms?
Photoheterotroph
A monophyletic group is....
Bonus: Circle on on the phylogenic tree
A common ancestor and all of its descendants
What are two reproductive isolation mechanisms the biological species concept uses? What is the difference between the two?
Prezygotic - Can't mate because of temporal, habitat, behavioral isolation, genetic barrier or mechanical
Postzygotic - hybrid viability (embryo dies) or hybrid sterility (hybrid is sterile)
Which mode of selection likely underlies the pattern of ‘character change’ when we look at the history of life on earth?
Directional
The fundamental characteristic 'information' requires organisms to take process information in two ways. How do prokaryotes do these two things?
(First determine what the two information processing criteria are. HINT: what is being processed)
Hereditary information: one circular chromosome
- Used to code for proteins
Environment information:
- At the level of chemistry
- Quorum sensing - responding by making enzymes, sensing concentration
- Chemotaxis- moving away or towards a chemical stimulus
Which of the following criteria will allow you to classify the organism as belonging to Bacteria but not Archaea or Eukarya?
A. It is unicellular.
B. Cell walls are made primarily of peptidoglycan.
C. The organism does not have nucleus.
D. The lipids in its plasma membrane consist of glycerol bonded to straight-chain fatty acids.
E. It can survive at a temperature over 100°C
Cell walls are made primarily of peptidoglycan
Explain the Principe of parsimony
When there are two competing theories, the simpler one should be preferred
In terms of trees: The tree with the least amount of changes is the most parsimonious (simple) and should be preferred over a tree with a lot of changes
What are three limitations of the biological species concept?
Not applicable to fossils
Only for sexually reproducing organisms
Populations need to overlap geographically
Reproductive isolation is not always 100%
What do all cells have in common?
(HINT: Think of biomolecules and structural components)
Biomolecules: lipids, nucleic acids, proteins, carbohydrates
Structural components: plasma membrane, chromosomes, ribosomes
In prokaryotes new mutations accumulate quickly in populations, while in eukaryotes new mutations accumulate much more slowly. The primary reasons for this are:
Prokaryotes have a faster rate of reproduction than eukaryotes do. (So more offspring with the mutation is created quicker in prokaryotes than in eukaryotes)
Name the four reasons why prokaryotes are important?
Give an example for one of them.
Ecosystem functioning -
EX: oxygen production (cyanobacteria)
Symbionts
EX: pathogenic bacteria (Firmicutes causes staph)
Biomedical
EX: (Diseases: Actinobactera, firmicutes, spirochetes ,chlamydiales, proteobacteria)
Reserach
EX: DNA technology (protea bacteria - e coli used in gene cloning)
Circle a sister group.
On the board
What are the three species concepts and what is the criteria for each of them?
Morphological -- species are morphologically distinct groups
Biological --species are groups of actually or potentially interbreeding populations that are reproductively isolated from other such groups
Phylogenetic -- species are the smallest monophyletic group on the tree of life
What are the 5 fundamental characteristics of life? And what are the patterns of life? What is the difference between the two?
5 Fundamental characteristics determines if something is alive or not:
- Cells, energy, information, evolution, replication
Patterns of life are the major patters that can be observed across life's history
- Character change, splitting, stasis, extinction, adaptive radiation
If prokaryotes create offspring that are genetically identical to the parent, how does genetic variation occur?
Which bacteria lineage best fits this description: Named for their shape; includes pathogens such as species that cause syphilis and Lyme disease
Spirochetes