Quiz #1 (2nd Semester)

phylogeny "tree of life", prokaryotes, protists

phylogeny

evolutionary history of a species or group of related species

taxonomy

ordered division and naming of organisms

systematics

scientific discipline of classifying organisms and determining their evolutionary relationships and history of different species

carolus linnaeus

he published a system of taxonomy; named over 13,000 species or organisms; grouping into broad categories

domain, kingdom, phylum, class, order, family, genus, species

Name the 8 major taxonomic groups from broad to narrow (largest to smallest)taxon

taxon

a rank or group in a biological classification into which taxonomists classify related organisms.

B

The various taxonomic levels (genera, classes, etc.) of the hierarchical classification system differ from each other on the basis of

A) how widely the organisms assigned to each are distributed throughout the environment.

B) their inclusiveness.

C) the relative genome sizes of the organisms assigned to each.

D) morphological characters that are applicable to all organisms

bacteria, archaea, eukarya

Name the 3 domains of life

genus

a principal __taxonomic__ category that ranks above species and below family, and is __denoted__ by a __capitalized__ Latin name

specific epithet

species identifier, what group in the genus are we talking about?

phylogenetic tree

a hypothesis about the evolutionary relationships between taxa -- they can change all the time

vertical or diagonal

what are the 2 different forms of phylogenetic trees

branch point

this is the part of the phylogenetic tree where lineages diverge

hatch marks

thie refers to traits that might have evolved from the past; homologous characteristic shared by all the groups to the right of the mark

sister taxa

taxa that are each other’s closest relatives; share exclusive common ancestor

basal taxa

1st thing to split off from the root (doesn’t usually split anymore)

polytomy

an unresolved pattern of divergence

cladistics

a system of constructing phylogenetic trees using shared characters and inferred common ancestry

clade

a group of species that includes an ancestral species and all its descendents - monophyletic

shared ancestral character

a character that originated in an ancestor prior to the clade of interest; ancestral state

shared derived character

character that is novel to a particular clade (synapomorphy)

ingroup

species or group of species being studied in a phylogenetic analysis

outgroup

species or group of species that is closely related to the ingroup but diverged before the ingroup

parsimony

assumes fewest evolutionary changes over time

maximum likelihood

includes likelihood of certain types of mutations and changes

homology

similarity due to shared ancestry between a pair of structures or genes in different taxa

analogy

similarity of function and superficial resemblance of structures that have different origins.

molecular clock

a method of estimating the date of past evolutionary events based on the amount of genetic change or divergence

peptidoglycan

bacterial cell walls contain _____ a network of polysaccharides cross-linked by polypeptides

taxis

ability to move toward/away from a stimulus

chemotaxis

movement toward/away from a chemical stimulus

phototaxis

movement toward/away light

plasmids

small circular pieces of DNA

rapid reproduction, mutation, genetic recombination

What factors contribute to prokaryotic genetic variation?

transformation

prokaryotic cell takes up and incorporates foreign DNA from environment

transduction

movement of genes between bacteria by bacteriophages

conjugation

genetic material is transferred between prokaryotic cells

C

Which of these statements about prokaryotic genetics is true?

A) Bacterial cells conjugate to mutually exchange genetic material.

B) Their genetic material is confined within vesicles known as plasmids.

C) They divide by binary fission without mitosis or meiosis. D) Genetic variation in bacteria is not present because of their asexual mode of reproduction.

phototrophs

obtain energy from light

chemotrophs

obtain energy from chemicals and organic molecules are obtained

autotrophs

require CO2 as a carbon source

heterotrophs

require organic nutrients to make organic compounds

obligate aerobes

require O2

obligate anaerobes

poisoned by O2

facultative anaerobes

can survive with or without O2, but grow best with O2

aerotolerant

can survive with or without O2 and show no difference in growth with or without O2

extremophiles

extreme environments

halophiles

live in highly saline environments

thermophiles

thrive in very hot environments

methanogens

live in swamps and marshes and produce methane as a waste product

bacterial species concept

genomic and phenotypic consistency

gram-positive

bacteria have simpler cell walls with a large amount of peptidoglycan; have a thick layer of peptidoglycan and appear purple as it absorbs a lot of dye; circular shape

gram-negative

bacteria have less peptidoglycan; have two cell membranes with walls in between; thin layer of peptidoglycan; appear pink as it absorbs less dye; elongated, rod tubular shape

symbiosis

ecological relationship in which two species live in close contact, a larger host and smaller symbiont

mutualism

both symbiotic organisms benefit

commensalism

one organism benefits while neither harming nor helping the other

parasitism

one organism (the parasite) harms its host

decomposers

organism that breaks down dead organic material

endosymbiotic theory

a class of hypotheses that view various organelles in eukaryotic cells as descendants of endosymbionts

prokaryotes

these cause about half of all human diseases

B

In general, what is the primary role of prokaryotes when considering the overall flow of chemicals and matter through ecosystems?

A) parasitizing eukaryotes, thus causing diseases

B) breaking down organic matter

C) metabolizing materials in extreme environments

D) serving as primary producers in terrestrial environments

host

a living organism that acts as a harbour for invading pathogenic organisms.

symbiont

any of several living arrangements between members of two different species, including mutualism, commensalism, and parasitism.

spherical, rod-shaped, spiral

what are the three different bacteria shapes?

parasite

an organism that lives on or in a host organism and gets its food from or at the expense of its host.

monophyletic group

includes an ancestor and all of its descendants

paraphyletic group

includes an ancestor and some of its descendants (but not all)

polyphyletic group

includes organisms that may show some sort of similarity but share more recent common ancestry with other taxa; this similarity is usually due to convergent evolution, not homology; these groups do not include the common ancestor of the taxa involved

paraphyletic

What kind of group are prokaryotes?

Carl Woese

Who introduced the 3 domain system in 1977?

paraphyletic

What kind of group is protists?

protists

single-celled eukaryotes are collectively referred to as ____ (also includes some colonial and multicellular species)

mixotrophs

combine photosynthesis and heterotrophic nutrition

Excavata, ‘SAR’ clade, Archaeplastida, Unikonta

Name the four ‘Supergroups’ of eukaryotes

B

All protists are: A) unicellular B) eukaryotic C) symbionts D) monophyletic

excavates

What supergroup?

• includes the diplomonads, parabasalids and euglenozoans

• characterized by:

  • reduced mitochondria

  • unique crystalline rod in flagella

  • ‘excavated’ feeding tube

kinetoplastids and euglenids

What are the two subgroups of the excavate euglenozoans

stramenopiles, alveolates, rhizarians

What are the 3 subgroups of SAR?

stramenopiles

What SAR subgroup?

• Have 2 flagella

  • A “hairy” flagellum

  • a “smooth” flagellum

• Has 4 subgroups

diatoms, golden algae, brown algae, oomycetes

What are the 4 subgroups of SAR stramnopiles?

diatoms

unicellular algae with a two-part glass-like wall of silicon dioxide; photosynthetic

golden algae

photosynthetic subgroup of SAR stramenopiles

brown algae

large, complex multicellular structures (“seaweeds”, kelp); photosynthetic

oomycetes

water molds; decomposers/parasites

alveolates

What SAR subgroup?

* membrane-bounded sacs, called alveoli under the plasma membrane (function unknown)
* has 3 subgroups

dinoflagellates, apicomplexans, ciliates

What are the three subgroups of SAR alveolates?

dinofagellates

What SAR alveolate?

• two flagella, and plates of cellulose armor for protection

• coral symbionts

• cause of harmful “red tides”

  • brevetoxins

apicomplexians

What SAR alveolate?

• almost all are parasitic

• have complex organelles at their apical end for entering cells

ciliates

What SAR alveolate?

• have cilia on their surface that help them move and feed

• many are predators

• have large “macronuclei” and smaller “micronuclei”

  • Can engage in a type of sexual exchange of genes by swapping micronuclei

rhizarians

What SAR subgroup?

• mainly amoboid

  • move and feed by thread-like pseudopodia

• Has 3 subgroups

pseudopodia

used in movement and as a tool to capture prey or obtain required nutrition.

radiolarians, foraminiferans, cercozoans

What are the three subgroups of SAR rhizarians?

radiolarians

What SAR rhizarian subgroup?

• internal skeletons of silica

• radiating pseudopodia capture small microorganisms and cytoplasmically stream them to the center of the cell

foraminiferans

What SAR rhizarian subgroup?

• porous multichambered calcium carbonate shells called tests

• pseudopodia extend through the pores of test

archaeplastida

What supergroup?

• Defining characteristic – photosynthetic due to a cyanobacterial endosymbiont (i.e. chloroplasts)

• has 3 subgroups

red algae, green algae, land plants

3 subgroups of archaeplastida

B

Green algae differ from land plants in that many green algae species...

A) are heterotrophs.

B) are unicellular.

C) have alternation of generations.

D) have cell walls containing cellulose.

unikonta

what supergroup?

• defining characteristic - DNA evidence

• 2 subgroups

amoebozoans and opisthokonts

What are the two subgroups of Unikonta?

amoebozoans

what unikonta subgroup?

• lobed-shaped pseudopodia

• includes slime molds which display very unique life-cycles