bis 2c lab practical

homology

characters present in organisms because they were inherited from a common ancestor

homoplasy

two structures with the same morphology, where this morphology was not inherited from a common ancestor (evolved multiple times independently)

Conflict vs Congruence

whether or not new data correlates with the hypothesized phylogeny (congruence) or doesn't correlate with the hypothesized phylogeny (conflict)

Cladograms

branch lengths are meaningless

Phylograms

branch lengths correspond to amount of evolution that has occurred since the last node

Chronograms

length of each branch shows absolute time (usually has a bar/scale)

What is LUCA?

Last Universal Common Ancestor. Last life form whose descendants persist today.

Major characteristics of Archaea

ether linkages, 70s ribosome, extremophiles (generally), haploid

Major characteristics of Bacteria

peptidoglycan in membranes, ester linkages, 70s ribosome, haploid

Major characteristics of Eukarya

membrane bound organelles, ester linkages, 80s ribosome, diploid

What is LGT and why is it problematic for phylogeny reconstruction?

Lateral gene transfer = transfer of genetic material between two organisms from one lineage to another

LGT is problematic for phylogeny reconstruction because distantly related species may appear more closely related than they actually are. Exchange of genes among UNRELATED organisms ERASES phylogenetic history

Transformation vs Transduction vs Conjugation

Transformation- dna brought in from environment

Transduction -virus or bacteriophage inserts new genetic material in host

Conjugation-between two bacteria via sex pili; exchange parts of genome (plasmids)

Rhizobium symbiosis

bacteria

found in roots of legumes

form round balls called nodules

plant uses ammonia created by bacteria; bacteria uses sugars from plant

mutualistic relationship (both benefit)

Anabaena (cynobacteria)

cyanobacteria can get nitrogen from the atmosphere --> plant (water fern) uses the nitrogen

cyanobacteria get shelter in plant's leaves

mutualistic relationship (both benefit)

termite hindgut

bacteria and archaea help digest cellulose (from wood diet) for the termite

bacteria and archaea get constant source of cellulose

symbiotic relationship (termite can't survive w/o bacteria and archaea) and a mutualistic relationship (both benefit)

belong in Microbial Eukaryotes and are methanogonic archaeons

What is bioremediation?

use of microbes to clean up contaminated soil and groundwater. Archaea and bacteria have very diverse metabolic capabilities, so they can metabolize contaminants cleaning up a lot of messes that would otherwise hurt the environment

energy source

light = "photo"

breaking chemical bonds = "chemo"

electron donor source

organic = "organo"

inorganic = "litho"

carbon source

organic = "hetero"

O=C=O = "auto"

ocular lens (eyepiece)

objective lens

how to calculate total magnification

capable of independent adjustment

objective lens vary in power - 5X, 10X, and 40X objectives

calculate total magnification by multiplying objective times ocular

coarse focus on microscope

the large one; typically only used at lower magnification levels; moves stage up and down

fine adjustment on microscope

the small one; makes smaller adjustments to the slide

stage clip on microscope

used to secure the slide

endosymbiont theory

Big organism engulfs small organism resulting in an additional membrane forming around it. If it is not digested it may form a symbiosis with the host and continue to live and reproduce inside the host organism

primary endosymbiosis

involves the engulfment of a bacterium by another free living organism.

Secondary endosymbiosis: occurs when the product of primary endosymbiosis is itself engulfed and retained by another free living eukaryote.

Euglena

flagella, photosynthetic (chloroplasts)

Blepharisma

cilia, not photosynthetic, eat bacteria or each other if no food source

Paramecium

cilia, not photosynthetic, food vacuole

Naegleria

change body forms based on how much food is in the environment

Non-amoeboid body form (flagella) is better suited for movement so is common when food source is absent or scarce

amoeboid body form is better suited for eating and so is common when food source is present

certain genes/body forms expressed @ certain environments (nutrient level) → need to get around faster to go longer distances to find food when nutrients decrease (amoeboid form very slow compared to flagellate)

problem with phylogeny bc of this

not photosynthetic

Chlamydomonas

flagella, photosynthetic

Stentor

cilia, photosynthetic (via photosynthetic relationships with algae)

Alteration of Generations life cycle

Liverworts

Non-vascular plant

no true stomata

sporophyte doesn't function in dispersal

flat 2D growth (thallose and leafy)

bryophyte

Moss

Non-vascular plant

3D growth

cap sporangium

sporophyte (with stomata) dependent on gametophyte

meristem cells at base - form new tissues

bryophyte

Hornworts

Non-vascular plant

green sporophyte

gametophyte does photosynthesis

sporophyte dependent on gametophyte

meristem cells at base - form new tissues

bryophyte

Lycophytes

Vascular plant

microphylls

true roots

sporophyte dominant

independent gametophyte

strobili (cones)

Dichotomous branching

Ex. lycopodium and selaginella

Evolved heterospory (in Selaginella --> a homoplasy)

Monilophytes

Vascular plant

Megaphylls

DO NOT produce seeds (seedless vascular plants)

Independent gametophytes, independent sporophyte?

Most monilophytes are homosporous but some (Water Ferns) are heterosporous.

DNA chloroplast inversion

Only 1 sporangi

Ex: psilotum, equisetum [horsetail], fern

Gymnosperm

Vascular Plant

Naked seeds

Nutritive tissue (n)

Integument, ovule, pollen with pollen tube,

heterospory

BVC (bivascular cambium)

Ex: Cycad, Ginkgo, Conifers, Gnetophytes

Angiosperm

Vascular Plant

flowering plants