methane
	carbon dioxide
	oxygen
	water
	nitrogen

	the continental shelves
	unglaciated terrain
	sedimentary rock
	igneous rock
	volcanic archipelagos, such as the Galápagos and Hawaiian Islands

	10,000 years
	12 billion years
	3.6 billion years
	0.3 billion years
	1,000 years

	Paleozoic, Cenozoic, Mesozoic
	Precambrian, Mesozoic, Cenozoic, Paleozoic
	Paleozoic, Mesozoic, Cenozoic
	Paleozoic, Mesozoic, Cenozoic, Precambrian
	Cenozoic, Mesozoic, Paleozoic

	Mammals had an opportunity to become dominant.
	Shallow marine habitat became scarcer.
	Extensive glaciation caused mass extinctions.
	The geographic isolation of populations that had previously coexisted led to speciation.
	Sympatric speciation became the primary means by which new species were formed.

	They have become different by convergent evolution.
	The climate of Australia is unlike that of any other place in the world.
	Australia was never in close proximity to the other continents.
	Life in Australia was wiped out by ancient volcanic eruptions.
	Australia has been isolated for about 50 million years.

	This mass extinction occurred about 245 million years ago.
	This mass extinction occurred at the end of the Permian period.
	This mass extinction occurred at the end of the Paleozoic era.
	This mass extinction occurred just before the beginning of the age of dinosaurs.
	All of the above statements correctly describe the most catastrophic mass extinction of all time.

	Fossils show that dinosaurs suffered from cold and starvation.
	Sedimentary rocks contain a layer of iridium, a mineral uncommon on Earth.
	There have been several near misses in recent years.
	The dinosaurs disappeared rather abruptly, virtually overnight.
	Fossils indicate that most dinosaurs were looking up when they died.

	the fossilized remains of simple plants that are over 5 billion years old
	3.8-billion-year-old rocks with isotopes of carbon that seem to represent the metabolic activity of organisms
	the mineralized remains of tiny animals
	the fossilized remains of cellular colonies dating from about 3 million years ago
	none of the above

	H2O only
	H2O and CH4 only
	H2O, CH4, and H2 only
	H2O, CH4, H2, and NH3
	H2O, CH4, H2, NH3, and O2

	life can be created in a test tube
	long chains of DNA can form under abiotic conditions
	simple organic molecules can form spontaneously under conditions like those thought to prevail early in Earth's history
	the earliest life forms introduced large amounts of oxygen into the atmosphere
	the "concentration gap" probably prevented simple organic molecules from polymerizing

	They may have been the source of some of the organic compounds that cells use in energy metabolism.
	Sulfides of iron and nickel common in deep-sea vents are excellent catalysts.
	The high temperatures associated with deep-sea vents were a source of energy for the reactions necessary for the formation of protobionts.
	Oxygen was abundant near deep-sea vents and encouraged the formation of polymers.
	All of the above are reasons that deep-sea vents may have been important to the origin of life.

	ability to absorb substances from their surroundings
	genetic library
	selectively permeable membrane
	transmembrane voltage potential
	ability to grow

	raw materials for organic compounds formed
	the formation of organic polymers, such as carbohydrates and RNA, were catalyzed
	primitive cell membranes could form, grow, and divide
	energy was supplied for the metabolism of the first simple cells
	all of the above

	DNA
	phospholipids
	viruses
	true proteins
	RNA

	were probably the first organisms to live on Earth
	produced atmospheric oxygen
	are the oldest known archaea
	were the first multicellular organisms
	extracted heat from the atmosphere, cooling Earth

	electron transport systems
	anaerobic fermentation
	aerobic respiration
	photosynthesis
	emergence of obligate anaerobes

	the ability to engulf other cells
	the ability to undergo mitosis
	anaerobic fermentation
	electron transport
	the ability to shift internal structures

	Mitochondria and plastids reproduce by a method that is very similar to binary fission.
	The inner membrane of both types of organelles have enzymes and transport systems that are homologous to those on the plasma membrane of prokaryotes.
	Each type of organelle contains a single circular DNA.
	The ribosomes of each type of organelle are more similar to cytoplasmic ribosomes of eukaryotic cells than to ribosomes of prokaryotic cells.
	Each of these organelles contains tRNA and other molecules need to translate DNA.

	term used to describe the horizontal transfer of genetic material between bacterial and archaeal lineages
	process by which the first eukaryotic cells performed meiosis
	process by which the first eukaryotic cells performed mitosis
	method by which archaea reproduce
	process by which the first self-replicating RNA formed

	Once the first multicellular eukaryotes appeared, their sizes and populations grew exponentially, like a snowball rolling down a hill.
	Multicellular eukaryotes had an advantage over single-celled organisms in extremely cold conditions.
	The first multicellular eukaryotes formed colonies on the surface of glaciers.
	Multicellular organisms evolved when conditions were so cold that plasma membranes of unicellular organisms fused.
	Larger multicellular eukaryotes are scarce in the fossil record until the late Proterozoic because an ice age limited life to deep-sea vents and hot springs.

	fungi
	animals
	insects
	cyanobacteria
	algae

	most species are photosynthetic
	of their rigid cell walls
	their metabolism was identical to that of plants
	bacteria and plants both have flagellated gametes
	bacteria contain cellulose in their cell walls

	Monera
	Protista
	Fungi
	Plantae
	Animalia

	Monera
	Protista
	Fungi
	Plantae
	Animalia