bio unit 1 exam

What is the nature of science?

science is the **process** of **gaining knowledge** and **investigating** the universe through **observation,** posing **questions** and **experimentation**

What is science?

science is a **fact-driven** exercise in understanding the universe, science demonstrated not asserted

definition of theory

explanation for a very general class of phenomena or observations that are supported by a large body of evidence

hypothesis

a testable statement to explain phenomena or observations, explanations for more tightly focused questions

prediction

measurable or observable result in an experiment that must be correct if a hypothesis is valid

characteristics of a scientific hypothesis

1. testable
2. falsifiable
3. measurable
4. reproducible
5. objective

hypotheses can be refined following _____

new evidence

there can be many hypotheses to explain a phenomenon, but most tests attempt to ______

identify the most likely explanation

steps of the hypothesis-based science

1. formulat a hypothesis
2. design an experiment or observational sampling scheme


1. include replicates
2. include controls
3. test hypothesis through objective experiment or observations
4. reject or fail to reject

______ keep most variables the same and manipulate a few variables

experiments

_______ are carefully designed to address hypotheses

observational studies

experiments and observational studies try to ____ the number of observations(replicates)

maximize

experiments and observational studies are valid ______

forms of science

major events in the history of life

1. cellular life
2. oxygen revolution
3. nucleated cells
4. multicellularity
5. Cambrian explosion

What is the 6th major extinctions that is currently happening

anthropogenic, or caused by humans

cellular life evolved ______ years ago

3\.8-3.5 billion

prokaryote

cells with no nucleus

cellular life is most likely: aerobic or anaerobic

anaerobic

science is _____

dynamic, changing as new evidence becomes available

scientific theories are not simply “ideas” but rather ______

supported by lots of evidence

modern examples of scientific theories

heliocentric, plate tectonics, evolution, relativity

a hypothesis needs replicates of both __ __and__ ___

control and treatment conditions

the earth is ____ years old

4\.6 billion

the oldest fossils are _____

stromatolites(prokaryotic blue-green algae)

how old are stromatolites

about 3.5 billion years

cellular life is mostly ____

heterotrophic

cellular life uses organic molecules for __ and ____

energy and carbon resource

oxygen began accumulating ___ years ago

2\.7 billion

it is hypothesized that ____ evolved as the supply o__f__ _______ dwindled

photoautotrophs, organic molecules

at first cells were prokaryotic

1. no membrane bound nucleus
2. lack organelles
3. divide by binary fission

eukaryotic cells

1. have a nucleus
2. divide by mitosis

approximately ___ years ago eukaryotic cells evolved

2 billion

multicellularity allowed for ____

specialization of tissues

multicellularity are ___ and ____

large and more complex organisms

cambrian explosion

“sudden” appearance of virtually all modern animal body plans

since the Cambrian explosion:

1. diversification
2. when species colonize an empty area they rapidly diversify to fill in specific niches

niche definition

a term for different types of resources used

limitations of fossil record: habitat bias- _____ needed to bury samples

sedimentation

limitations of fossil record: habitat bias- what are better than rainforests for fossilization

swamps, beaches, mudflats, and dunes

limitations of fossil record: taxonomic and tissue bias- ___ fossilize better than _____

hard parts(bones, shells, etc), soft parts

limitations of fossil record: temporal bias- recent organisms more ____ than ancient ones

abundant

limitations of fossil record: abundance bias- abundant organisms more abundant in the fossil record than ______

rare organisms

measuring biological diversity

estimates are varied because of different method of measuring diversity

extant biodiversity variation variation

between 10-100 million species

biodiversity best estimate

30 million extant species

phylogeny

represents hypothesized evolutionary relationships

node definition

most recent ancestor

sister taxa definition

pairs of terminal taxa and/or clades that branch from a common node and are often considered closely related

clade definition

a grouping that includes a common ancestor and all the descendants (living and extinct) of that ancestor.

common ancestor definition

 an ancestral group of organisms that is shared by multiple lineages

synapomorphies definition

a shared, derived traits

paraphyletic groups(or outgrips) definition

an unnatural group that does not include the most recent common ancestor

homology

shared traits derived from a common ancestor

homoplasy

similarity in organisms due to reasons other than common ancestry

taxonomy

the scientific study of naming, defining and classifying groups of biological organisms based on shared characteristics

phylogenetic trees

 the evolution of the species or groups of species

________ names are standardized and universal

scientific

______ names are of limited utility

common

______ is a rapid evolution of a clade, frequently happens on islands

adaptive radiation

all species share a _____

common ancestor

prokaryotes are _____

ubiquitous, numerous, and diverse

basic characteristics of prokaryotes

unicellular, ring of DNA, plasmids, and reproduce by binary fission

basic characteristics of eukaryotes

linear DNA, multicellular, mitochondria, membrane bound nucleus, flagella, cilia, divide by mitosis, have cell walls

archaea cell walls

do NOT contain peptidoglycan

archaea often categorized as ______

extremophiles

both bacteria and archaea use ____ to swim

flagella

how do archaea reproduce

asexually- binary fission

bacteria estimated to be ____ diverse

MUCH more

bacteria

unicellular, prokaryotic, microscopic, lacking a nucleus, and having a plasma membrane

bacteria cell wall is made up of

peptidoglycan

archaea membranes

uses ether linked lipids as opposed to ester linked lipids in bacteria

bacteria membranes

made of phospholipids

bacteria has histone proteins

false

archaea has histone proteins

true

energy-sun

photo-

energy-other organisms

organic-

energy- inorganic

litho-

carbon- CO2

\-auto-

carbon- other organisms

\-hetero-

organism uses sun for energy, CO2 for carbon

photoautotroph

# organisms uses organic molecules for energy, CO2 for carbon

organoautotroph

# organisms uses inorganic molecules for energy, CO2 for carbon

lithoautotroph

organism uses sunlight for energy and other organisms for carbon

photoheterotroph

organism uses organic molecules for energy and other organisms for carbon

organoheterotroph

organism uses inorganic molecules for energy and other organisms for carbon

lithoheterotroph

metabolisms that prokaryotes can perform

all 6 metabolisms

metabolisms that eukaryotes can perform

photoautotrophs and heterotrophs

earth’s first inhabitants

prokaryotes

first fossil prokaryotes are approximately ______ years old

3\.5 billion

obligate aerobes

require oxygen for respiration

obligate anaerobes

poisoned by oxygen

facilitate anaerobes

can use oxygen for respiration, but not required

aerotolerant anaerobes

do not use oxygen but are not poisoned by it

factors that limit prokaryotic reproduction

waste accumulation, competition from other microorganisms, consumption by other microorganisms, and exhaustion of food resources

binary fission does not allow for ______

recombination

prokaryotes use ______ to introduce genetic diversity

transformation, transduction, and conjugation

prokaryotic morphology- size

generally smaller than eukaryotic cells, but there are exceptions

prokaryotic morphology- structure

simple internal structure

prokaryotic morphology- unicellular or multicellular

unicellular

prokaryotic morphology- movement

use flagella and cilia to move