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Classification
-Similar features
-Animal/Vegetable/Mineral
-Micoscopes
--micoorganisms
-Kingdoms
--bacteria(prokaryotes)
--Animals, plants, fungi, single-celled eukaryotes
-Based on morphological features
Genetics
-We resemble our relative bc we share many alleles(specific versions of genes)
--Most accurate measure of relatedness is how similar genomes are
DNA
material of inheritance, common to all organisms
rRNA
-First widely compared sequences
--Life depends on protein synthesis
--Ribosomes must function to make proteins
--Genes for ribosomal RNA evolve very slowly
Prokaryotes
-Bacteria
-Archaea
--Neither have a nucleus
--Archaea are more closely related to eukaryotes
Membrane enclosed nucleus is present in?
Eukarya
Membrane enclosed nucleus is absent in?
Bacteria and Archaea
Membrane enclosed organelles in eukarya?
Many
Membrane enclosed organelles in Archaea?
Absent
Membrane enclosed organelles in Bacteria?
Few
Peptidoglycan in cell wall in Eukarya?
Absent
Peptidoglycan in cell wall in Archaea?
Absent
Peptidoglycan in cell wall in Bacteria?
Present
Membrane lipids in Eukarya?
Ester-linked and unbranched
membrane lipids in Archaea?
Ether-linked and branched
Membrane lipids in Bacteria?
Ester linked and unbranched
Ribosomes in Eukarya?
80S
Ribosomes in Archaea and Baceria?
70S
Initiator tRNA in eukarya?
Methionine
Initiator tRNA in Archaea?
Methionine
Initiator tRNA in Bacteria?
Formylmethionine
Operons in Eukarya?
Rare
Operons in Archaea and Bacteria?
Yes
Plasmids in Eukarya?
Rare
Plasmids in Archaea and Bacteria?
Yes
Number of RNA polymerases in Eukarya?
Three
Number of RNA polymerases in Archaea and Bacteria?
One
Ribosomes sensitive to chloramphenicol and streptomycin in Eukarya and Araches?
No
Ribosomes sensitive to chloramphenicol and streptomycin in Bacteria?
Yes
Ribosomes sensitive to diphtheria toxin in Eukarya and Archaea?
Yes
Ribosomes sensitive to diphtheria toxin in Bacteria?
No
Gram Staining
Peptidoglycan in cell wall
Gram positive
cell wall take sup violet dye, dense cell wall of peptidoglycan
Gram negative
appears pink or red, very thin layer of peptidoglycan and an outer membrane.
Coccus
sphere shape
Bacillus
rod shape
Helix
spiral shape
Prokaryotes rely on what for movement of materials through cell?
Diffusion
Quorum sensing
Triggers biofilm formation
Prokaryotes reproduce by...
fission but can exchange genetic material
How do prokaryotes exchange genetic material?
Horizontal or vertical transfer
Horizontal gene transfers
complicates use of sequences to determine phylogenies
Vertical gene transfers
Generation to generation as in multicellular organisms
Metabolism/Environment in Prokaryotes
Oxygen is poisonous to some prokaryotes
--Anaerobes
Others require oxygen
--Obligate aerobes
Others can use either!
--Facultative anaerobes
Cyanobacteria in nutrition
-Photosynthesis
--Photoautotrophs
---Converting Earth's atmosphere to aerobic in ancient past
Photoheterotrophs
Harvest energy from light but rely on sugars made by other organisms
Chemoheterotrops
feed on other animals
Decomposers
break down dead bodies
Nitrogen fixers
convert N2 from atmosphere to NH3
Nitrifying bacteria
NH3--->NO2--->NO3
Available to plants for amino acid, nucleic acid synthesis
Denitrifying
convert organic nitrogen to N2
Beneficial prokaryotes in health and disease
rumen flora of cattle have cellulase- eat grass
--Lehume roots house nitrogen fixing bacteria
Harmful pathogens of prokaryotes
Anthrax in sheep, cattle, and sometimes humans
--Agrobacterium in plants:crown galls
Pathogens (prokaryotes)
-Only a tiny percentage of prokaryotes are pathogens
How prokaryotes cause disease
Invade the body, evade immune system, multiple, produce toxins
Endotoxins (host exposed when bacteria lyse)
Fever, vomiting, diarrhea
Exotoxins (related by living bacteria)
Highly poisonous or fatal
Features of eukaryotes
Organized nucleus
-Linear chromosomes, membrane-bound
Organelles
-Mitochondira
-Chloroplasts
-Digestive vacuoles
Organelles
Membranes associated with specialized fucntions
Vesicles
Move materials in and out of cell
Cytoskeleton
Movement relies on this
-Predation
-Change shape
-Increased size
Chromosomes and Sex (eukaryotes)
-Linear DNA molecules
-All have a sexual life
-Meiosis
Eukaryotes include..
Plants, Animals, Fungi (ALL MULTI CELLULAR)
-Protists (usually single-celled)
Multicellular organisms after cell division...
cells stay together
-provides opportunity for specialization
-Greater size
Superkingdoms
Plants
Animals
Protists
-Single celled
-Diverse, polyphyletic
-Many niche
-Flagella, cilia, pseudopods
-can be complex
Opisthokonts
Flagellum is posterior, single
-Animals (multicellular)
-Fungi(uni or multi)
Choanoflagellates -- opisthokonts
Can be colonial
-first step toward multicellularity
Fungi -- opisthokonts
cell wall of chitin
multicellular or uni
absorptive heterotrophy
-enzymes are secreted, break down food, absorbed
-can feed on living or dead organisms
-fungicides are toxic to animal cells
--major role in decomposition of dead organisms
Fungi can be beneficial or harmful to other organisms
fungal infections in animals
-Plant pathogens: rusts, smuts
-Symbiosis: mycorrhizal dungi-allo trees to take up more minerals from sol
-Lichens: fungus + green algae
Amboebozoans
use pseudopods for motility
-aquatic (fresh water)
-moves via pseudopods
-eats via phagocytosis
-Predator scavenger, or parasite
Physarum -- amboebozoans
plasmodial slime mold
-terrestrial (forests)
-dispese, then aggregate to form fruiting bodies
-ingest by endocytosis
-move my cytoplasmic streaming
Dictyostelium -- amboebozoans
cellular slime mold
-Amoeba-like single sells aggregate into slug when dry or starved
-are retained, form spores
Rhizaria
unicellular, aquatic, long pseudopods, marine
Foraminiferans -- rhizaria
external shells of calcium carbonate
-source of limestone
-psedudopods ensnare plankton
Radiolarians -- rhizaria
glassy endoskeletons
-include some of the largest unicellular eukaryotes
-can have photosynthetic endosymbionts--dinoflagellates
Archaeplastids
land plants (multicellular)
Red algae -- archaeplastids
Marine
photosynthetic
chlorophyll a, phycoerythrin
Green algae -- archaeplastids
chlorophyll a, b
-uni or multi cellular
--multicellular:
volvox - spheres of flagellated cells
sea lettuce - marine
Stramenopiles
have unequal flagella
Diatoms -- stramenopiles
silica in cell walls - upper and lower like a petri dish
-aquatic: fresh and salt
-photosynthetic : storage products oils
- Diatomaceous earth : filtration
Brown algae - stramenopiles
can be multicellular
-sea palms, giant kelp
-phtosuntethic
-chlorophyll a,c + brown pigments
--source of emulsifiers of ice cream
Alveolates
sacs under cell membrane
single celled
paramecium --alveolates
ciliate
body covered with cilia - motility
fresh water
sex : equal exchange of nuclei
dinoflagellates -- alveolates
red tides
plasmodium -- alveolates
apicomplexans
parasite causing malaria
-life cycle in mosquitoes, human blood
--none functional chloroplasts
Excavates
unicellular, often lacking mitochondria, named surface groove
giardia --excavates
diplomonad
many flagella
lacks mitochondria
fresh water - parasite causing giardiasis
Euglena -- excavates
a euglenid
-photosynthetic
-if in the dark, eats!
--anteriror flagellum
Trypanosome -- excavates
kinetoplastid
-parasite causing sleeping sickness
Endosymbiosis
Green algae, land plants: chloroplast (cp) from cyanobacterium endosymbiont
- Enclosed by 2 membranes: one from cyanobacterium, one from host cell
• Serial endosymbiosis: more than 2 membranes around cp
- Brown algae, diatoms, dinoflagellates: 4 membranes Cp derived from red algae endosymbiont:
inner 2 membranes from algal chloroplast next out from cell membrane of red alga outermost from host
- Euglenids: cp from green algal endosymbiont
Viruses
composed of protein coated DNA or RNA encoding small number of proteins
Are viruses alive?
Acellular
Mutate
Evolve
Interact with other organisms
Derived from living organisms
Virus Classification
Based on nucleic acid type
-RNA or DNA
Positive sense RNA viruses
genome is also template for translation
-rhinovirus, polio, plant diseases, zika
Negative sense RNA viruses
Upon infection, viral encoded ran-dependent ran polymerase makes complimentary strand
-template for translation
-rabies, measles, mumps, ebola ---In terms of virus genomes, "negative sense" means that a single-stranded nucleic acid molecule has the opposite sequence to messenger RNA (mRNA) and so cannot be translated into protein until it has been copied
RNA retrovirus
protein component includes reverse transcriptase-->DNA
-proviral DNA is integrated into host's genome
-Specific to vertebrate animals
-HIV
DNA viruses
smallpox, herpes, bacteriphasge
Ebolavirus
Genome encodes 7 genes
-L gene
Converts viral RNA into template for translation
-Virsus multiples-spreads in host and can infect new hosts
--Interferes with immune response, and disrupts vascular endothelial cells:hemorrhage
What is an animal?
Multicellular
-Cells adhere after biotic division
-Cells communicate with each other
Heterotrophic: eat other organisms
Internal Digestion
Motility
-Muscles, nerves, skeletons
Animal Diversity
Monophyletic
-common ancestor thought to resemble choanoflagellates
-Earliest and simplest animals are marine