evolution and classification Flashcards
molecular clock
using genetic sequence data to figure out what mutations occurred over time
All living things should have these Characteristics of life:
homeostasis, response to stimuli in enviornment, reproduction, metabolism, growth, evolution, composed of biomolecules, nucleic acids, cell structure
viruses have
reproduction, evolution, nucleic acids, responds to stimuli in environment, composed of biomolecules, have genes
Transcription in cells
process of taking dna sequence and going from Dna to Mrna (messenger rna) to do this process you need rna primer
Translation:
process of going from Mrna to protein to do this you need a ribosome and trna and rna and a protein
Rna world
original life was rna based
Origins of viruses
-Some appear to be from rna world based on really ancient rna sequences
-Some viruses are escaped transcripts from cells
-Some are highly simplified cells
genome
main genetic
Dna shape
double helix so if dna gets damaged there’s another strand that could maybe not be
Rna shape
coil so if rna gets damaged there’s only one strand
Importance of viruses
-Viruses are parasitic and use host cells to reproduce
- some viruses may take host membrane with them for disguise
- Some viruses leave their genetic material in the host’s genome
Bacteria vs viruses
-Bacteria has one distinct origin and can be placed on the tree of life (branches that stick off independently from each other)
horizontal gene transfer
-Plasmid dna can be exchanged between different bacterial cells
- Can have genes for antibiotic resistance or various metabolic reactions
cell wall is made of
peptidoglycan
gram negative can be more medically dangerous
-Lipopolysaccharides (LPS) trigger inflammation and are toxic
-Outer membrane can block antibiotics
-Antibiotics: only effective against bacteria since they target peptidoglycan walls or bacterial ribosomes
Cyanobacteria
-originators of photosynthesis
-Form some of the oldest known fossils (stromatolites)
-Added a lot of oxygen to the early atmosphere (probably killing off other oxygen intolerant organisms)
Nitrogen
fixing bacteria: split nitrogen atoms from N2 gas and build them into organic molecules like ammonia that other organisms can use
– Plants like beans or other legumes have these bacteria in their roots
Alpha Proteobacteria
Some of these evolved aerobic respiration to protect themselves from oxygen damage
Domain Archaea
somewhat intermediate between bacteria and eukarya in cell structure
Genetically, a distinct domain of life
Domain Eukarya
includes animals, plants, fungi and “ protists” (often single celled eukaryotes that don’t fit in the other kingdoms)
Characteristics of eukaryotes:
-Membrane-bound organelles and nucleus
-Mitochondria
-Linear chromosomes
Endosymbiosis
origin of eukaryotes (main cell was probably archaea, and then bacteria became mitochondria and chloroplasts of these cells.
Evidence
- Mitochondria and chloroplasts have loop dna very similar to alpha bacteria and cyanobacteria
Have bacteria- like ribosomes
Have inner membranes more similar to bacteria
Natural history
study of species, their diversity, distributions, or how they change over time.
Natural history collection information
measurements of specimens places and dates collections
genetic information
useful for de-extinction
taxonomy
study of how to name and describe species
linnaeus contributions
1) scientific name: Genus and species (ex. Homo sapiens)
2) categorical classification system:
- phylum
- class
- order
- family
- genus
- species
linnaeus system relies entirely on ______ similarities
metaphorical (physical)
mutation
letter change in Dna or Rna
clade
a group comprising an ancestral lineage and all it’s descendants lineages
monophyletic group
a “good” taxonomic group
- includes ancestor and all species that descend from it
homologous trait
similarity that two species share in common where it’d come from a common ancestor
analogous trait
similarity in 2 species due to adaption to similar environment ( convergent thinking)
fossilization
many fossils are formed when organisms are covered by sediment in water
- Leaves impressions of hard parts in sedimentary rock
to make a fossil you can use
freezing, amber, ice and tarr to store fossils and coal deposits
dating fossils ( Stratigraphy)
relative dates from positions of fossils with rock layers ( younger closer to surface)
protists
eukaryotes that don’t fit into the plant, fungi, or animal kingdoms
Protists ecological grades
Algae- photosynthetic,
Flagellates: use flagellum to swing
Amoebas: slow-moving, can change cell shape
Symbionts: live in close association with other species ( often as parasites)
population
group of organisms
Lamarckian evolution
involves use and disuse of parts and inheritance of acquired traits
- may apply to things like horizontal gene transfer and epigenetics
epigenetics
how genes are turned on or off
Natural Selection
organisms adapt to their environments
-Organisms that are better adapted survive better and produce more offspring
-Fitness: how well an organism survives and reproduces
Social Darwinism (Later eugenics)
A misunderstanding of natural selection as a justification to favor certain groups of people over others
fungae
have no chloroplast but mitochondria like animals
plants use mitochondria in cells and use _______ to burn carbohydrates
aerobic respiration
