BIO1802: Exam #2

true or false: phylogeny can be drawn in different ways

true

phylogeny relationships

have not changed

what was the hypothesis regarding whales in the 1970s-1980s

hypothesized to be most closely related to mesonychids; new dna evidence led scientists to reevaluate fossil evidence

tool for studying phylogenic history

phylogenetic tree

what do branch lengths represent

genetic change; proportional to the amount of genetic change in each lineage

what do different branch lengths indicate

genes evolved at different rates

homology

similarity that results from common ancestry

same structure, different function comes from

owing to shared common ancestor

do the wings of these birds serve the same function (penguin, ostrich, bird)

similarity not due to function, due to shared ancestry

homoplasy

similarity in organisms due to reasons other than common ancestry

polyphyletic group

unnatural group that does not include the most recent common ancestor

paraphyletic group

group that includes an ancestral population and some of its descendants, but not all

analogies are a result of what

convergent evolution

permineralized fossils

minerals that replace organic material in fossil (bone, wood, etc.)

example of permineralized fossils

calicte, iron, silica

how do permineralized fossils form

in the original shape of the tissue or organism

true or false: permineralized fossils preserve minute details like cell structure

true

step 1 of fossil formation

animal dies and is protected from scavenging

step 2 of fossil formation

animal becomes covered by sediment and permineralization occurs

step 3 of fossil formation

geologic pressure converts sediment/soil to rock

step 4 of fossil formation

shifts in geologic formations or erosions may alter shape of rock formation, exposing fossil

what affects whether a fossil is formed

lots of processess

rarities of fossils/fossilization

fossilization, fossilization of whole organisms

finding fossils depends on what

finding exposed surfaces where fossils may have been deposited

what type of rock are the richest source of fossils

sedimentary rocks

law of superposition

in any undisturbed sequence of rocks deposited in layers, the youngest layer is on top and oldest on bottom (geochronology)

geochronology

youngest layer on top, oldest on the bottom

radiocarbon dating of fossils

recent past only, within 50,000 years owing to short half (life of C14)

what does radiocarbon dating measure

C14 atoms remaining in the sample

U → Pb

commonly used in paleontology to date rock surrounding a fossil

what is used to age layers of rock

radiometric dating; apply law of superposition

what has the study of fossils allowed in regards to a geologic record

standard time scale that divides Earth’s history into 4 eons, smaller subdivisions

how do stromatolites form

binding of photosynthetic prokaryotes with thin films of sediment

cambrian explosion

unparalleled emergence of organisms between 541 million and approximately 530 million years ago

when does adaptive radiation occur

when species rapidly evolve to fill new ecological roles

typical lifespan of a species is one million years so..

each year 1 of every million species should go extinct

if there are 10 million species, how many species go extinct per year

10 species per year

what is the extinction rate from species

area curve is 27,000 species per year

who is the father of microbiology

antony leeuwenhoek

who was the first to see microbes

antony leeuwenhoek

where do microbes come from

family; especially from the mother throughout young growth

antibiotic resistance

germs like bacteria and fungi develop the ability to defeat the drugs designed to kill them

themes of diversification morphological diversity

vary in sizes, shapes; can move around, glide, some do not move

gram positive

plasma membrane and proteins are lower; cell wall is on the outside

gram negative

outer membrane with polysaccharides sandwiched between plasma membrane

gene transfer

introduction of new DNA into an existing organism's cell

binary fission

creates clones of each other/copy of itself

transformation

moves around in medium and encounters something and changes on own

transduction

virus bringing in material from the outside; incorporation and genetic material

conjugation

two bacterial cells that combine using a conjugation tube; movement between different bacteria

autotroph

makes energy itself

heterotroph

energy from molecules produced by other organisms

phototrophs

energy from sunlight

how does bacteria generate energy

autotrophs, heterotrophs, phototrophs

chemoorganotrophs

makes energy from organic molecules

photoautotroph

cyanobacteria photosynthesize in a pond

chemolithotrophs

makes energy from inorganic molecules (inorganic)

in the nitrogen cycle, what is a pollutant

extra nitrogen (N)

nitrogen cycle steps

1. nitrification (NH3 to NO3-)

2. assimilation (Incorporation of NH3 and NO3- into biological tissues)

3. ammonification (organic nitrogen compounds to NH3)

4. denitrification(NO3- to N2)

mississippi river dead zone

excess of nitrogen

what helps plants photosynthesize

chloroplasts

chloroplasts

contains chlorophyll that allows them to photosynthesize

coleochahaetes

green algae, part of plantae algae group

cambrian group

first land plants

carboniferous group

extensive coal-forming swamps

jurassic and triassic

wet and dry environments blanketed with green plants for the first time

what is the first evidence for nonvascular plants

cuticle, pores, spores, sporangia

nonvascular plants

lack structure, grows close to the ground, does not have vascular tissue to support

cuticle

prevents water loss

pores

captures CO2 converts it to what we need to survive; help prevent water loss

spores

reproduction; goes through some level of aquatic medium in water

vascular plants have

vascular tissue, stomata, stoma, roots/leaves

stomata

modified cells that provide stoma; helps open and close to prevent water loss

stoma

open and close based on moisture in air

when does the stoma close

when dry and hot

when does the stoma open

when moist and cool

vascular tissue

creation of stem, movement up laterally from the ground, get up top and soak up sun before plants that are lower

vascular tissue lignins

xylem

xylem

moves water and nutrients up and down plant

what are the first seeds that start to show up

coal forming swamp section

gymnosperms

wet/dry environments both have plants; first push on the land further in dryer conditions; seeds

pollen

male component; fertilizes eggs of the female part of the tree

seeds

embryo that forms in plants (middle)

outer edge of the seed

nutritive tissue (like the placenta)

cycads

distinctive reproduction, produce coralloid roots, ability to nitrogen fix

ginkgo

only living representatives of ginkagophyta (“living fossil”), monotypic

phylum pinophyta

the pine cones open up when conditions are right, seeds are then dispersed

• temperature, precipitation, change driven

oldest living phylum pinophyta

bristlecone pine (5000 years old)

when do serrotenous pinecones open

when they get really hot

phylum cupressophyta

depends on fire for reproduction, thick bark to prevent burning from fires, really large

phylum gnetophyta

seeds and ability to survive in dry environments

ephedra controversy

helps lose weight and suppresses appetite, derived from gymnosperms, FDA banned it

flowering plants

angiosperm, ovary protected, has to be pollinated by moving around from boy flowers to girl flowers by a pollinator

gymnosperm

seeds

fruit

dispersed by animals, way that seeds are dispersed

native bees

evolved to pollinate many plants in North America, focus on specific plants and families of plants

predict what would pollinate it by piecing together

smelly plants → flies pollinate these instead of bees

does flower color influence pollinator preference

yes, hawk moths like white; bumblebees like purple

magnoliids

form a separate group that evolved before monocots and eudicots “dicots”

2 groups of angiosperms

monocot and eudicots (“dicots”)