BIS 2C Lab Practical Exam

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

seeds

Double fertilization results in nutritive tissue (3n)

endosperm

Majority of plants

Reduced gametophyte- only 7 cells

Phloem with companion cells - sieve element

Reproduction involves flowers and pollinators

Are both tracheids and vessel elements

Basal Angiosperms vs Monocot vs Eudicot

Basal Angiosperms = non-monophyletic group

Monocots- bifacial vascular cambium (BVC) absent; scattered vascular bundles; 1 cotyledon; flower parts in threes and multiples of three; parallel leaf veins;

Dicots- BVC present; organized vascular bundles; 2 cotyledons; leaf veins form a net pattern; flower parts in 4s or 5s and their multiples

Algal relatives of Plants

green algae (Coleochaete and Chara) have the same photosynthetic pigments, the same type of flagella, and the same fundamental process of cell division

Types and trends of growth

Filamentous growth: 1 cell is cut vertically in half, divides, then a new cell forms in between

Branched growth: cell is cut in half horizontally

Apical growth: land plants specialization; the cell at the tip; youngest cell is closest to the apex (tip/end) (like a tree, new growth on top, furthest from base which is older)

Cutting faces: # of directions in which a cell divides (flat body only 2 cutting faces, 2D; 3D growth for 3 cutting faces (upward))

Two basic types of leaves and when did they evolve?

Megaphylls- complex vasculature; evolved in the MRCA of monilophytes

Microphylls-single vein of vasculature; evolved from sterilized sporangia

Bifacial vascular cambium

Pushes new vasculature to grow out instead of up, resulting in wider plants

Separates new and old vascular tissues.

Xylem grows inwards, phloem outwards

Gymnosperm vs Angiosperm life cycle

gymnosperm life cycle: megagametophyte remains in nutritive tissue (2N) and is made even if not fertilized; m. and f. cones; both megasporangia make 4 megaspores (N), only 1 surivves

angiosperm life cycle: flowers (can be perfect or imperfect); no cones; ovary wall (2n) around seed coat (2n); nutritive tissue is result of double fertilization and is the endosperm (3n) and is only made when embryo is present

Ways flowers attract pollinators

orchids look like female bees (males try to mate with flower and get pollen on them instead)

long nectar tubes attract moths with equally/similarly long tongues

Moth: white, no landing pad, strong odor

Hummingbird: red, lots of nectar, no landing pad

Bee: nectar, landing pad

Fly: mottled color, foul odor

Simple fruit

Develops from 1 flower w/ a single carpel --> 1 fruit; have many seeds (apple, banana, mango, grapes)

Aggregate fruit

1 flower many fruit (blackberry) results from several carpels on a single flower

Multiple fruit

many flowers merge together to form a fruit (pineapples)

Accessory fruit

formed from non-ovary tissue (strawberries)

Role of secondary metabolites in plants

produces a large number of specialized compounds that do not aid in the growth and development of plants but are required for the plant to survive in its environment

secondary plant metabolites are useful in the long term, often for defense purposes, and give plants characteristics such as color

Secondary plant metabolites are also used in signalling and regulation of primary metabolic pathways

Monophyletic groups/sister taxa tend to have similar secondary metabolites (i.e. citrus and mint in lab)

Epiphytes (from Conservatory tour)

a plant that grows harmlessly upon another plant (such as a tree) and derives its moisture and nutrients from the air, rain, and sometimes from debris accumulating around it

not a parasite bc do not negatively affect host (just rely on them for physical support)

Ex: spanish moss

Carnivorous plants

hot, humid, wet areas, nutrients washed away, so catch insects for nutrients; leaves always catch insects

Sarraceniaceae (Pitcher plant family) N America, few in S america → pleistocene b/c continental drift (cacti more likely older b/c more widespread than sarraceniaceae)

Droseraceae (sundew family) triassic period when all continents together → now found all across the world

Nepenthaceae (tropical pitcher plant family) Malasia/Indonesia or Madagascar (Cretaceans), Jurassic period if could travel by wind dispersal (more recent if can disperse a far way)

Venus fly trap (North Carolina)

Stem modifications

water retention w/ accordian bulbous shaped stem; 2 types of stem (on 1 plant)--bulbous (stores/retains water and nutrients and starch/sugars) on bottom, and thin on top for photosynthesis; stems not as efficient at photosynthesis, but can still do it

Rhizomes, tubers

Leaf modifications

Holes in upper canopy leaves (nearer to sun) allows to stay cool easier and better for winds

Small, thin leaves that close/fold in when touched to protect against predators and strong winds (lose less moisture) - Mimosa pudica

Sweet leaves (extremely) to protect against being eaten (stevia plant)

Square shape w/ spores on edge--1 'branch' w/ lots of the square leaves is actually 1 entire leaf: very organized, with a lot more spores and easier dispersal of spores

Smaller leaves grouped to look like a flower that are fuzzy --> repels water to not be over watered and stays on surface of water

Ascomycetes

Fungi

Largest phylum of Fungi

Ex. yeast, used for beer/wine making, truffles, brewer's yeast

Shoot spores

haploid

Basidiomycetes

dykarion

Lichens and their symbiosis

Lichen are the result of a symbiosis between ascomycota + (algae or cyanobacteria) + yeast

Fungi provide shelter, algae or cyanobacteria produces food from photosynthesis, yeast protects by producing toxic vulpinic acid

Porifera

spicules (silica/calcium)

networks of collagen

choanocytes = filter water and capture food

asymetrical

no gut

Ex: sponges

Ctenaphora

use rows of cilia to move themselves (cilia in rows called combs/ctenes)

radial symmetry

diploblastic development

complete gut

Ex: comb jellies (not related to jellies!)

Cnidaria

sting-bearing nematocysts/cnidocytes for protection and capture of prey

polyp reproduces by budding or fission

can be colony or medusa forms

2 way gut

radial symmetry

Ex: Corals, sea anemones, box jellies, true jellies (jellyfish), Portugese Man o'War, etc.

Annelida

Bilaterally symmetrical coelomate protostomes with segmented (metameric) body

each segment with paired bundles of chitinous setae, and parapodia (polychaetes only)

body wall with inner longitudinal and outer circular muscles

each segment the same

each unit contains locomotory, reproduction, excretory, and respiratory structures

Triploblastic (mesoderm)

complete 1 way gut

cephalized

spiral, mosaic cleavage

trochophore larvae

Ex: leeches, earthworms, bristleworms

Mollusca

Bilaterally symmetrical (secondarily asymmetrical)

coelomate protostomes with: complete gut,reduced coelom open circulatory system

in most, well developed nervous system (especially in cephalopods)

trocophore larva

synapomorphies: mantle (4 functions), foot, radula(inside mouth); spiral, mosaic cleavage; cephalization

Ex: chitons, bivalves, gastropods (snails and limpets), and cephalopods (squid)

Arthropoda

protostomes

bilateral symmetry

exoskeleton (more energy required to shed and secrete new exoskeleton regularly, and they are vulnerable before new one hardens; grow in size by molting exoskeleton; reabsorb nutrients before completely shed old exoskeleton; muscles are attached to basement cuticle, under the layer that sheds)

segmentation

ecdysis

triploblastic

1 way complete gut

cephalization

horseshoe crabs and insects = 3 tagmata; jointed appendages (crustaceans have specialized appendages for feeding, walking, and swimming)

insects are hemimetabolous (make small increases in body size w/ each molt and juvenile resembles adult) or holometabolous (dramatic changes in form during their life, i.e. caterpillar to butterfly)

Ex: spiders, scorpions, horseshoe crabs (living fossil), centipeeds, crustaceans, insects

Echinodermata

Adults = radial symmetry (usually pentaradial) Deuterostomes

able to regenerate tissue, organs, limbs, and reproduce asexually

ossicles

calcite endoskeleton

water vascular system

tube feet

radial, regulative cleavage

Ex: sea stars, sea urchins, sand dollars, sea lillies, and sea cucumbers

Chordata

have notochord

bilaterally symmetrical

deuterostome coelomates

Vertebrate chordates can have body plans organized via segmentation

Postanal tail

endostyle

dorsal, hollow nerve cord

triploblastic

complete 1 way gutf

Ex: fish, amphibians, reptiles, birds, mammals, sea squirts, and lancelets

Types of symmetry

radial = many axis of symmetry

Ex: sea anemone

bilateral = one cut of symmetry separating organism into a left and right half

Ex: humans

Usually tied to cephalization and a complete gut

pentaradial = 5 pt symmetry

Ex: sea star

asymmetrical = not symmetrical

Ex: sponge

Types of digestive systems

Complete gut (one way)-mouth and anus

Incomplete gut (two way gut)-blind gut, food and waste exit same hole

Cephalization

head vs no head

(involves concentrating neural cells and morphologies in one area to form a central control area)

Associated with bilateral symmetry with exceptions in bivalves and echinoderms (echinoderms are not cephalized; lost this when they 'changed' symmetry from bilateral to pentaradial)

Metazoan development

zygote (2N) --> radial/spiral cleavage --> blastula --> gastrula

Identify key features on a dissected bivalve (i.e. mussel)

Know where the foot, radula, mantle, shell, gills, etc. are located

Identify key features on a dissected squid

Know where the inc sac, pen, siphon, mantle, tentacle, etc. are located

Identify key features on a dissected earthworm

Know where the crop, nerve cord, clitellum, etc. are located