Fundamental Characteristics
Energy, Cells, Information,Replication, Evolution
Robert Hooke
Made first microscope
Anton van Leeuwenhork
Made microscope 300x more powerful
Cells
Flexible structure called plasma membrane. Concentrated chemicals in aqueous solution.
Cell Theory
All organisms are made of cells. Cells come from pre existing cells
Hypothesis
testable statement
Prediction
describes a measurable result
Theory
Collection of knowledge built up through repeated statistical testing of hypothesis.
An explanation for a very general class of phenomena.
Pasteur
Made an experiment to test the cell-to-cell (cell theory) hypothesis
True or false? All species are connected by a common ancestor
True
Population
group of individuals of the same species living in the same area
Artificial Selection
Changes in a population caused by humans selecting individuals to produce the most offspring
Carl Woese
analyzed the chemical compounds of organisms to understand their evolutionary relationships
rRNA
Made up of ribonucleotides; A, U, C & G
Why is rRNA useful for understanding the relationship between organisms?
The ribonucleotide sequence can change overtime during evolution.
LUCA
Last universal common ancestor
Hypothetic-deductive model
Null hypothesis and alternative hypothesis. Reject null or fail to reject null
Systematics
Study of biodiversity
Carl Linnaeus
Created the two part name used today for naming species. Genus->Species.
The scientific name.
Taxonomic Hierarchy
Domain, Kingdom, Phylum, Class, Order, Family,Genus, Species.
Dirty Kittens Play Catch On Filthy Germy Seats
True or False? Last year 18,000 new species were names.
True
Domains:
Archaea, Bacteria & Eukarya
Archaea:
Single-celled organisms without a nucleus (Prokaryotic), Live in extreme environments (hot, salty, acidic, etc). hyperthermophiles live in highest temps.
Bacteria:
Most common single-celled prokaryotes, Responsible for many human diseases.
Eukarya Kingdoms:
Protista, Plantae, Fungi, Animalia
Protista:
Unicellular and simple multicellular eukaryotes
Plantae:
Multicellular autotrophic eukaryotes.
Make their own food (photosynthesis) using clorophylls a and b.
Have cell walls made of cellulose, a polysaccharide
Fungi:
Multicellular heterotrophic eukaryotes.
Decompose (externally digest) food, then absorb it.
Have cell walls made of chitin, another polysaccharide.
Animalia:
Cells always lack cell walls.
Multicellular.
Heterotrophic (must ingest food)
Upupa epops
Hoopoe (bird)
True or False? The exterior surface is the most important deterrent to infections.
True
Innate immune response
first response to pathogens
Leukocytes
white cells
Tears contain____ which acts as a_____
lysozyme enzyme; Antibiotic
Steps in inflammatory response:
1. platelets
2. Leukocytes called macrophages secrete chemokines
3. Mast cells release histamine
4. Leukocytes called neutrophils destroy invading cells.
5. Cells produce additional cytokines
Parsimony principle
The preferred explanation of observed data is the simplest explanation
Morphology
The shape and appearance of an organisms body
Phylogenetic approach
Begins with morphology and genomics.
Determines historical relationship.
Evolutionary pathways.
Phylogenies
nodes that represent hypothetical common ancestors
Analogous
have separate evolutionary origins, but are superficially similar because they have both experienced natural selection
Homologous
meaning that they are similar because they descended from genes in a common ancestor.
Monophyletic group
common ancestor and all the descendants. (Lineage or clade)
Polyphyletic group
does not include the common ancestor of the group
Paraphyletic group
the common ancestor and some, but not all, descendants
Data that constructs phylogenies
Morphology (physical structures), Development (notochord), Paleontology (fossils), Behavior (frog calls), Molecular (genomic sequencing)
Cladistic approach
is based on the principal that relationships among species can be reconstructed by identifying shared derived characters (synapomorphy)
Synapomorphy
a trait found in two or more taxa that is present in their most recent common ancestor but is missing in more distant ancestors
Homology
same-source" similar traits due to shared ancestry
Homoplasy
same-form" when traits are similar for reasons for reasons other than common ancestry
Characteristics of prokaryotes
Single celled
No nuclear membrane
No organelles
No cytoskeleton
No mitosis
No sexual reproduction
Where are prokaryotes found?
Free living, Parasitic, Biofilm
Why are prokayotes so succesful?
Distinctive cell walls
Locomotion
Fast reproduction
Communication
Diverse metabolism
Characteristics of Bacteria
Limited membrane structure
Single circular "chromosome" with few proteins
Small ribosomes
Dominant life forms
Bacteria and archaea
Extremophiles
Bacteria or archaea that live in extreme environments
What do extremophiles have to do with?
Origins of life, Extraterrestrial life, Commercial application
Where do pathogens tend to affect tissue?
wounds & pores, respiratory & gastrointestinal tracts, Urogenital canal
What is Koch's postulates used for?
to confirm a causative link between new diseases and a suspected infectious agent
________ laid the foundation for modern medicine.
The germ theory of disease.
True or false? Large portions of bacteria and archaea cause disease
False
A simple method of separating bacterial into two larger groups
Gram staining
Gram positive bacteria
(purple) high levels of peptidoglycan
Staphylococcus aureus
Example of gram positive bacteria.
Can cause illness
Gram negative Bacteria
(pink) Two layers of cell membrane with a thin layer of peptidoglycan
Escherichia coli
Example of Gram negative.
most strains harmless
Two diversification themes:
Morphology & metabolism
Prokaryotic locomotion
Many can't but some are motile; flagella.
Flagella:
consists of a single protein called flagellin.
Propelling movement
How do bacteria and archaea produce ATP?
Phototrophs "light-feeders", Chemoorganotrophs oxidize molecules with high potential energy, Chemolithotrophs "rock-feeders" ammonium and methane
How do bacteria and archaea fulfill their carbon-carbon need?
Autotrophs "self-feeders"
Heterotrophs "other-feeders
True or false? Data suggest Archaea and Eukaryotes evolved after Bacteria
True
True or false? Viruses are living organisms
False