chapter 15

The appearance of archosaurs in the Triassic period of the Mesozoic era began what is known as the ______, which lasted from the Triassic period to the Cretaceous period.

Age of Reptiles

Due to the significant and widespread effects of humans on the land, biodiversity, and climate, scientists propose that a new geological epoch has begun, called the

Anthropocene

Four to five species of the hominin genus ______ existed from about 4 to 2.5 million years ago.

Australopithecus

The Burgess Shale deposit shows a tremendous diversity of fossils from the ______ period of the Paleozoic era.

Cambrian

What term is used to describe a period of intensive animal diversification on Earth 543 million to 490 million years ago?

Cambrian explosion

Many species of worms, armored animals, shelled organisms, and trilobites arose in seas containing algae during the

Cambrian period of the Paleozoic era.

The ______ period of the Paleozoic era is also called the "Age of Amphibians."

Carboniferous

The ______ era is sometimes called the Age of Mammals, due to the adaptive radiation of mammals that occurred during the ______ period.

Cenozoic; Paleogene

The importance of the Miller experiment was that it was the first prebiotic simulation experiment to re-create chemical conditions that might have been present on early before life arose.

Earth

What is true about Ediacaran organisms?

They lived during the end of the Precambrian.

What marks the end of the Ordovician period?

a mass extinction

Select all of the following that are true about all species of the genus Homo.

considered human associated with stone tools larger brains than australopiths

DNA analyses indicating a close relationship between mitochondria and proteobacteria and between chloroplasts and cyanobacteria support the

endosymbiosis theory.

What evolved about 1.9 to 1.4 billion years ago?

eukaryotic cells

As depicted in the image, what step in the origin of life on Earth likely occurred immediately after the formation of monomers such as amino acids, nucleotides, monosaccharides?

formation of polymers

Select all the effects of the replacement of a hunter-gatherer lifestyle in Homo sapiens with the ability to increase food availability with agriculture.

formation of specialized occupations improved communication increased ability to explore new lands improved transportation

Climatic changes in East Africa, the Middle East, India, and much of Europe that began about 12 million years ago may have contributed to the evolution of

hominins.

Gibbons, orangutans, gorillas, chimpanzees, and humans all belong to the lineage of primates called the

hominoids.

Monkeys that live in Africa and Asia are called World monkeys, and monkeys that live in South and Central America are called World monkeys.

old new

The endosymbiont theory proposes that

the mitochondrion and chloroplast organelles of eukaryotic cells originated as free-living bacteria.

The ______ era lasted from 543 to 248 million years ago and is divided into six periods: the Cambrian, the Ordovician, the Silurian, the Devonian, the Carboniferous, and the Permian.

Paleozoic

What fossil is the oldest representative of the hominin lineage to date?

Ardipithecus ramidus

The first flowering plants appeared on land during the

Jurassic period of the Mesozoic era.

In his 1938 book titled The Origin of Life, ______ hypothesized that the absence of atmospheric ______ could have allowed nucleotides and amino acids to form.

Oparin; oxygen

Select all the correct statements regarding the lesser and great apes.

Orangutans, gorillas, chimpanzees, and humans are considered great apes. Gibbons are considered lesser apes.

Fossilized spores indicate that primitive plants ventured from the water to land during the ______ period of the Paleozoic era.

Ordovician

What organisms existed during the Ordovician period?

algae, corals, clams, ostracoderms, primitive land plants

What organisms existed in the Cambrian period?

algae, sponges, jellyfishes, worms, nautiloids, and trilobites

The first multicellular organisms to evolve were likely

algae.

Select all the characteristics of recent Homo.

arose from early Homo around 500,000 years ago lighter brow ridges associated with culture and tools

Select the three main groups that belong to the primate lineage.

monkeys prosimians hominoids

Select all the types of organisms that arose during the Silurian period of the Paleozoic era.

terrestrial animals vascular plants jawed fish fungi

What geologic time period is known as the "Age of Reptiles"?

Mesozoic erav

Gymnosperm plants became very prominent during the ______ period of the Paleozoic era.

Permian

Fossils of Australopithecus indicate that these hominins moved by

bipedal locomotion.

What skeletal adaptation might be present in a primate that moves by brachiation?

shoulder joint that allows 360-degree movement

Rank the following steps leading to the origin of a cell in the order they may have occurred, beginning with the earliest step at the top. Instructions

-simple precursor chemicals are present-small organic molecules form, such as amino acids, lipids, and nucleotides-polymers such as RNA and polypeptides form-genetic material encodes proteins, and lipid spheres form-formation of protocell, self-replicating system enclosed in a membrane

The Precambrian supereon spans what time period, approximately?

0.5 to 4 BYA

Eukaryotic cells arose about

1.5 bilion

Rank the order of time periods in the geological timescale from the longest at the top to the shortest at the bottom. Instructions

1.eons 2.eras 3.periods 4.epochs

By about ______ years ago, Homo sapiens began to shift out of the hunter-gatherer lifestyle with the development of ______ to obtain food, which allowed specialized occupations to arise in human societies.

10,000; agriculture

Early signs of culture in Homo sapiens is demonstrated in cave art that dates to about ______ years ago.

14,000

Prokaryotic cells were the first life forms on Earth and arose approximately

3.5 billion years ago.

The oldest known fossils are ______ years old and resemble formations made by ______.

3.7 billion; cyanobacteria

While geologic processes have destroyed most of Earth's initial crust, rocks that are about ______ years old have been found in Greenland.

3.85 billion

The first reptiles evolved about ______ million years ago during the Carboniferous period of the Paleozoic era.

300

The oldest hominin, Ardipithecus ramidus, dates back to

4.4 million years ago.

The species Homo sapiens had migrated out of Africa and colonized Europe, Asia, and Australia by about ______ years ago.

40,000

Fishes with jaws and freshwater fish arose during the Silurian period about

443 to 417 million years ago.

Humans and chimpanzees share a common ancestor that lived about ______ million years ago.

6

Primate ancestors that gave rise to the first ancient humans arose during the Neogene period about

6 million years ago.

The reign of giant reptiles on Earth ended about ______ million years ago due to a mass extinction that occurred at the end of the Meoszoic era.

65

The DNA nucleotide sequence of chimpanzees and humans are at least ______ identical.

96

While skin tone and some physical features differ in human populations due to microevolutionary forces, all living humans are

99.9% genetically similar.

The Carboniferous period of the Paleozoic era lasted over 50 million years and has been referred to as the "Age of ______."

Amphibians

Rank the hominin groups in the order they evolved, beginning with the earliest group at the top. Instructions

Ardipithecus 2. Australopithecus 3. Paranthropus 4. Homo

Select the four groups into which fossil hominins have been categorized.

Australopithecus Ardipithecus Homo Paranthropus

A mudslide during the Cambrian period preserved many organisms in a formation called the ______ that contains abundant and diverse fossils of Cambrian animals.

Burgess Shale

Underground coal beds contain the remains of ______ plants, such as forests of ferns and early seed plants.

Carboniferous

Select time periods from the Paleozoic era.

Carboniferous Cambrian Devonian Permian

Select the three reasons that clay could have been important in the polymerization of organic molecules on early Earth.

Clays consists of sheetlike minerals, forming flat surfaces. Some minerals in the clays could have acted as catalysts. Some clays contain minerals that release electrons, providing energy.

During what period of the Mesozoic era was Triceratops very abundant and widespread?

Cretaceous period

Fossils indicate that seed plants, ferns, and horsetails evolved during the ______ period of the Paleozoic era.

Devonian

The "Age of Fishes" refers to which of the following geologic time periods?

Devonian

The first amphibians appeared toward the end of the ______ period of the Paleozoic era.

Devonian

Select all of the following statements about early Earth that are correct. Refer to the figure.

Earth's crust formed approximately 4.2 billion years ago. The first animals arose in the ocean about 570 million years ago. Eukaryotes arose about 1.5 billion years ago.

What Precambrian organisms had a variety of forms, became extinct around 544 million years ago, and left no known descendants?

Ediacarians

During the ______, early Earth was subjected to ultraviolet radiation, volcanic eruptions, earthquakes, and bombardment by meteorites.

Hadeon eon

Fossils of the genus ______ are associated with stone tools and have larger brains and bodies than australopiths.

Homo

Select all the species that are considered "early Homo."

Homo habilis Homo ergaster Homo erectus

Of the following species of the genus Homo, which one is still alive?

Homo sapiens

Select all the species that are considered "recent Homo."

Homo sapiens Homo heidelbergensis Homo neanderthalensis Homo floresciensis

Select all the ways in which humans could be considered the dominant species on Earth.

Humans have colonized most continents. Humans have changed other species to fit their needs. Humans have altered the Earth's surface.

Select all the hypotheses that describe how single-celled life forms may have developed into multicellular life forms.

Individual cells united, and groups of cells took on specialized life tasks, forming a multicellular organism. An individual cell divided and the two cells remained together; this process repeated, resulting in a multicellular organism with specialized cells.

The first mammals were small and arose during the

Jurassic period.

What is true about the DNA found in the eukaryotic organelles that were derived from the endosymbiosis of proteobacteria and cyanobacteria?

Many genes have moved to the nuclei of the host cells.

The figure represents the apparatus used by

Miller to duplicate the conditions on early Earth and determine if organic molecules could arise.

The continents approached their current positions during the

Neogene period.

Select all of the following that describe the conditions on early Earth.

Numerous volcanic eruptions and earthquakes were occurring. Atmospheric pressure was at least 10 times the pressure of present Earth. Surface temperatures ranged from 500oC to 1000oC. It cooled enough to form a crust about 4.2 billion years ago.

What is the difference between Old World monkeys and New World monkeys?

Old World monkeys are native to Africa and Asia, and New World monkeys are from South and Central America.

Select all the important events that occurred during the Precambrian supereon.

Oxygen accumulated in the Earth's atmosphere. Photosynthesis evolved. Multicellularity arose. Life originated.

What hominin existed 3 to 1.5 million years ago, had large teeth and protruding jaws, and did not give rise any other hominin genus?

Paranthropus

Reptiles that laid amniotic eggs arose during the ______ period.

Permian

The cotylosaurs were reptiles of the early ______ period that eventually gave rise to pelycosaurs (sailed lizards), dinosaurs, and all other reptiles.

Permian

Select all the ways that the evolution of photosynthetic organisms affected subsequent changes on Earth.

Photosynthetic organisms became energy sources for other eukaryotic organisms. Ozone formed, which blocked ultraviolet radiation Aerobic organisms began to evolve.

The appearance and extinction of several species of human (genus Homo) occurred during the ______, but only one species survived to the present.

Pleistocene epoch of the Quaternary period

Several ice ages in which huge glaciers covered 30% of Earth's surface and then withdrew occurred during the

Pleistocene epoch of the Quaternary period.

The ______ epoch comprises nearly all of the ______ period in the Cenozoic era.

Pleistocene; Quaternary

An extinct group of organisms that existed during the ______ were the Ediacarans, and the Ediacarian period is named in their honor.

Precambrian

The geologic time period that covers 2.58 million years ago to present is called the ______ period.

Quaternary

In some prebiotic simulation experiments, ______ molecules were formed on clay surfaces with positive charges.

RNA

Select all the reasons why RNA may have been the first informational molecule.

RNA can catalyze chemical reactions. RNA can duplicate itself. RNA can use stored information to produce proteins. RNA stores genetic information.

What idea proposes that RNA could have been the first self-replicating precursor to life on Earth?

RNA world

Select all of the following that are true about the evolution of the genus Homo.

Several species of hominin lived in Africa at the same time. Homo sapiens is the only remaining species. Scientists speculate that H. sapiens may have interbred with H. neanderthalensis.

The first plants to have vascular tissues evolved during the ______ period of the Paleozoic era.

Silurian

What correctly describes the size of ancient amphibians?

Some were up to 9 meters long.

In his book titled ______, Oparin suggested that ______ could have formed in a reducing atmosphere.

The Origin of Life; amino acids and nucleotides

Select all the correct statements regarding the Quaternary period.

The Quaternary period is the present geologic time period. Ice sheets and glaciers formed and receded during parts of the Quaternary period. The Quaternary period is part of the Cenozoic era.

Select all the correct statements regarding the asteroid and the resulting mass extinctions that ended the Mesozoic era.

The asteroid was about 10 kilometers in diameter. So much debris was cast into the atmosphere that photosynthesis was essentially nonexistent for about 3 years. The point of impact of the asteroid was near the Yucatán peninsula.

A bubble composed of a phospholipid membrane is called a

The bacteria and archaea split apart from a common ancestor between 3 BYA and 2.5 BYA. Archaea and bacteria, even though simpler than eukaryotes, still flourish today.

Select all of the evidence suggesting that the chloroplasts of some photosynthetic organisms arose by the endosymbiosis of a eukaryotic photosynthetic cell (secondary endosymbiosis).

The chloroplasts have three or four membranes. The chloroplasts retain remnants of a nucleus.

Select geological, biological, and climate changes that occurred during the Paloegene period of the Cenozoic era and that affected speciation and extinctions of organisms during this time period.

The oldest known bat fossil dates to the Paleogene period. Wet, warm forests were widespread. Tectonic plates shifted and created mountains.

Select all the evidence used to support the endosymbiont theory proposed in the 1960s.

There are similarities in photosynthetic pigments in chloroplasts and cyanobacteria. There are similarities in the size, shape, and membrane structure of chloroplasts, mitochondria, and bacterial cells. Chloroplasts and mitochondria contain DNA, RNA, and ribosomes, which are similar to those in bacterial cells. Mitochondria and chloroplasts divide in a way that is similar to bacterial division.

Select all of the following that are true about the Cretaceous period of the Mesozoic era.

Tyrannosaurus existed in western North America. Flowering plants were extremely diverse. Marine reptiles were present in the seas. Birds and pterosaurs shared the skies. Dinosaurs moved in large herds.

The end of the Devonian period is marked by

a mass extinction of marine life.

What event correlates with the evolutionary explosion of life that began around 1.5 billion years ago?

accumulation of oxygen in atmosphere

After a week of running the experimental apparatus shown in the image, what did Miller find in the pinkish, condensed liquid at the bottom?

amino acids

The products of Miller and Urey's 1953 experiment contained

amino acids.

Select all of the following that were likely components of Earth's early atmosphere, as proposed by Oparin in his 1938 book.

ammonia (NH3) methane (CH4) water (H2O) hydrogen (H2)

Select all of the following that went extinct at the end of the Mesozoic era about 65 million years ago.

ammonites pterosaurs plesiosaurs nonavian dinosaurs

What key characteristic evolved in early reptiles that allowed embryonic development to occur completely on dry land?

amniotic egg

Toward the end of the Devonian period of the Paleozoic era, ______ first appeared.

amphibians

Select all the organisms that were abundant and flourishing during the Carboniferous period of the Paleozoic era.

amphibians bryozoans foraminiferans ferns insects

What organisms existed during the Carboniferous period?

amphibians, bony fishes, sharks, giant dragonflies, seed plants

All the major phyla of ______ appeared during the Cambrian explosion.

animals

Select all of the following changes that occurred about 12 million years ago that may have contributed to the evolution of hominins.

appearance of open plains new food resources on African savannas formation of the Himalayas

Reptiles called ______ arose during the Triassic period and were the ancestors of dinosaurs.

archosaurs

Many reptile groups that survived the Triassic period and continued to evolve in the Jurassic period

became larger and dominant.

Select all of the skeletal adaptations present in humans that allow locomotion by bipedalism.

big toe not opposable long, strong leg bones bowl-shaped pelvis

Select the feature that is unique to members of the genus Homo and absent in chimpanzees and gorillas.

bipedal locomotion

A primate fossil with a foramen magnum located beneath the skull, rather than at the rear of the skull, likely moved by ______, which is walking upright.

bipedalism

Being able to carry objects and use tools may have been advantages of ______ for early hominins living in the open plains.

bipedalism

Humans have a bowl-shaped pelvis, fixed big toes, and robust lumbar vertebrae, all skeleton adaptations for what type of locomotion?

bipedalism

Some hominoids, such as gibbons and orangutans, move among tree branches by ______, swinging from one arm to another as the body dangles beneath.

brachiation

The use of tools and language is related to the development of larger ______ in humans.

brains

Miller's experiment was criticized because he did not use the gas ______, even though it was abundant in the early Earth's atmosphere. When it is present, organic molecules still form.

carbon dioxide

Quartz crystals found in the 3.85-billion-year-old Isua rock formation in Greenland contain

carbon isotopes found in organisms.

After RNA arose and the synthesis of proteins and DNA began, protein molecules eventually took over many of RNA's ______ roles, and DNA molecules became stable molecules for ______.

catalytic; information storage

What key feature of complex organisms was made possible by the evolution of multicellular organisms?

cell specialization

Around 4 billion years ago, the first ______ formed.

cells

Through molecular techniques, scientists have discovered that the genes of humans and ______ are nearly identical.

chimpanzees

Select all of the following included in the lineage of primates known as hominoids.

chimpanzees orangutans humans gibbons gorillas

What evidence indicates that an asteroid colliding with Earth near the Yucatán peninsula caused a mass extinction at the end of the Cretaceous period?

clay-filled impact crater layer of iridium in Cretaceous rock huge semicircle of sinkholes

What may have provided a surface for the linking of organic monomers because it contains minerals that may have had a catalytic role?

clays

What repeatedly hit Earth's surface during its first 500 to 600 million years?

comets, asteroids, and meteorites

Select all the organisms that were present in the seas during the Ordovician period of the Paleozoic era.

corals sponges algae clams jawless fish

Knowledge, beliefs, and behavior are all part of ______, which is a by-product of the large human brain.

culture

Select all of the unique characteristics of the modern human species.

culture, knowledge, and beliefs can change faster than biological evolution activities can have effects on Earth's climate

The evolution of photosynthesis made which of the following possible? Select all that apply.

decrease in atmospheric CO2 concentration evolution of aerobic organisms accumulation of atmospheric oxygen formation of ozone

What may have caused the mass extinction at the end of the Ordovician period of the Paleozoic era?

decreasing temperatures as Gondwana drifted toward the South Pole

The size and shape of fossil teeth reveal information about a primate's

diet.

Multicellular animals, plants, and fungi arose from

different lineages of protists.

The capacity of nucleic acids to mutate in progenotes may have allowed the evolution of

different metabolic pathways.

Fossils of Homo that date back to 2 million years ago would be considered

early Homo.

In Miller's experimental design to test Oparin's prediction about Earth's early atmosphere, what did Miller pass the gases through to simulate lightning?

electrical discharges

According to the theory, free-living bacteria were engulfed by prokaryotic cells and eventually became chloroplasts and mitochondria.

endosymbiont

Although scientists do not know the exact origin of eukaryotic cells, the ______ theory does explain the origin of the mitochondria and chloroplasts.

endosymbiosis

Select all of the following that are true about Paranthropus.

evolved from Australopithecus existed more recently than Australopithecus

Rising and falling global temperatures, advancing and retreating glaciers, and changes in the gases in the atmosphere have led to numerous

extinction and speciation events.

Select all the new species of plants that evolved during the Devonian period of the Paleozoic era.

ferns horsetails seed plants

What very successful type of fishes first arose during the Devonian period?

fishes with bony skeletons

The family tree of hominins has been constructed mostly based on

fossil features.

Select all the types of fossils present in the Green River formation in Wyoming that dates back to the Eocene epoch of the Paleogene period, 50 million years ago.

freshwater fish crocodiles and snakes flowering plants and ferns bats insects and snails

Select all the Pleistocene mammals that went extinct.

giant sloths saber-toothed cats North American camels mastodons and mammoths

Match each term with the primates it describes. Instructions hominoids lesser apes hominids

gibbons, orangutans, gorillas, chimpanzees, humans gibbons orangutans, gorillas, chimpanzees, humans

Select all the characteristics shared by primates.

grasping hands with opposable thumbs large brains relative to body size eyes set in the front of the skull fingers and toes with flat nails

Select the types of habitats that opened up for mammals due to climate change and geologic events during the Paleogene period.

grasslands forests woodlands

During the Permian period, what type of plant became more prominent?

gymnosperms

A diversity of what type of mammals grazed the grasslands of North and South American during the start of the Paloeogene period?

hoofed

Although not the most numerous species, ______ can be considered the current dominant species on Earth due to colonization and alteration of Earth.

humans

The cladogram shows that

humans and gorillas share a more recent common ancestor than humans and orangutans do.

Select all the gases that Miller and Urey used in their 1953 experimental apparatus.

hydrogen methane water vapor ammonia

Photosynthesis likely arose first in aquatic bacteria that used ______ as an electron donor.

hydrogen sulfide

In places called ______, cold ocean water mixes with minerals from Earth's interior under high temperatures, and these may have been the sites of simple organic molecule synthesis on early Earth.

hydrothermal vents

In general, the size of reptiles ______ from the Triassic to the Jurassic period of the Mesozoic era.

increased

Select all the advantages that may have led to the evolution of bipedalism in early hominins living on African savannas.

increased ability to carry objects freed hands to use tools

Multicellularity arose

independently in multiple lineages.

Extensive deposits of ______ provide evidence that Earth's atmosphere began to contain oxygen released from photosynthesis beginning about 2 billion years ago.

iron

In deep-sea hydrothermal vents, what may have acted as a catalyst for the reactions that formed simple organic compounds?

iron

Dark skin pigmentation is more common near the equator because it

is more protective against UV radiation.

Some types of primates have skeletal adaptations for ______, which is running along the ground with the weight resting on the knuckles.

knuckle-walking

Select all the characteristics of the amphibians of the Carboniferous period.

laid eggs in water life cycle still tied to water

Select all the organic molecules that Miller and other researchers were able to create using different mixtures of chemicals in early Earth prebiotic simulation experiments.

lipids nucleotides amino acids carbohydrates ATP

Using the figure, select all the correct statements about the diversity of life.

liposome.

The earliest cells probably all

lived in the absence of oxygen.

What type of fishes evolved during the Devonian period and had fleshy, powerful fins that could be used as feet?

lobe-finned fishes

Select all of the skeletal adaptations in a primate fossil that might indicate locomotion by knuckle-walking.

longer arms than legs foramen magnum opening at the back of the skull

Select all of the following that are prosimians.

lorises lemurs tarsiers aye-ayes

Lobe-finned fishes and early amphibians could obtain oxygen from the environment from both gills and

lunglike structures.

The very large asteroid impact on Earth at the end of the Mesozoic era opened up many habitats previously occupied, and the ______ underwent an adaptive radiation during the Cenozoic era.

mammals

What occurred at the end of the Cretaceous period?

mass extinction of dinosaurs that opened up habitats

Select all of the following that occurred at the end of the Triassic period of the Mesozoic era.

mass extinction that affected many aquatic and land animals rise of the large dinosaurs

The term "RNA world" describes the possibility that self-replicating RNA

may have been present in multiple forms, forming a pre-life community of molecules.

Under the right temperature and pH, phospholipids may have formed from precursors and assembled into

membrane-like structures.

Some evidence indicates that clays may have played an important role in the formation of early macromolecules. What component of clay may have acted as a catalyst to speed chemical reactions?

minerals, such as iron pyrite

Chloroplasts and mitochondria both developed in eukaryotic cells through endosymbiosis, though were probably the first of the two organelles to develop because they are found in all eukaryotes.

mitochondria

The endosymbiont theory explains the origin of which two eukaryotic organelles?

mitochondrion chloroplast

The Permian period ended with a mass extinction event in which

more than 90% of marine species in shallow water areas died; on land many insects, amphibians, and reptiles also died.

What may have allowed different metabolic pathways to arise in progenotes?

mutation of nucleic acids

Select the major gases found in Earth's present-day atmosphere.

nitrogen carbon dioxide oxygen water vapor

Chromosomes of humans and chimpanzees are extremely similar; one main difference is that humans have ______ due to the fusion of two smaller chromosomes early in the lineage that led to humans.

one less chromosome pair

What did the earliest cells likely use as a source of carbon and energy?

organic molecules

Use the diagram to place the following events of early Earth in order, from the earliest event at the top to the most recent at the bottom. Instructions

origin of life -origin of photosynthesis -oxygen beginning to accumulate in the atmosphere -oldest eukaryotic fossil

According to Oparin's book The Origin of Life, the atmosphere of early Earth did not contain ______ gas.

oxygen

The atmosphere of Earth today primarily contains the following gases: carbon dioxide, water vapor, nitrogen, and .

oxygen

The right temperature, pH, and precursor molecules could have allowed ______ molecules to form membrane-like structures.

phospholipid

What pathway evolved that allowed some types of early cells to use carbon dioxide as a source of carbon and sunlight as a source of energy to synthesize their own food molecules?

photosynthesis

Liposomes are formed when

pieces of a phospholipid membrane assemble into a bubble.

While land animals were largely spared, many marine organisms, such as jawed fishes called ______, became extinct at the end of the Devonian period.

placoderms

During the Silurian period of the Paleozoic era, the first with vascular tissues evolved.

plants

The name Carboniferous means "coal bearing." During the Carboniferous period, ______ dominated the landscape in tremendous areas of swamps and forests and were preserved as coal over millions of years after they died.

plants

As the figure proposes, sunlight may have provided the energy and iron pyrite in clays could have acted as a catalyst for the

polymerization of nucleotides.

The arrangement of minerals in sheets within clays may have provided a surface in which chemical building blocks could have been linked to form

polymers.

Miller's experiment was the first ______, and it showed how ______ could form from the simple molecules that were likely present on early Earth.

prebiotic simulation; biological molecules

Progenote, protocell, and protobiont are terms that describe

precursors of cells.

Monkeys, apes, and humans all belong to a group of mammals called ______ and share a suite of physical characteristics.

primates

An ancient aggregate of RNA, DNA, proteins, and lipids is called a

progenote.

The first cells on the Earth were

prokaryotic.

About 4 billion years ago, clays may have been the sites of RNA synthesis because their surfaces

promote the formation of covalent bonds.

Lemurs, lorises, tarsiers, and bush babies are all examples of a group of primates called

prosimians

The primate lineage contains three groups: the ______ (lemurs, lorises, and tarsiers), the monkeys, and the ______ (apes, including humans).

prosimians; hominoids

In the "RNA world," RNA may have begun to encode ______ that act as enzymes, and when the enzyme reverse transcriptase arose, a more stable informational molecule called ______ could have been made from RNA.

proteins; DNA

In the evolution of eukaryotic cells, the endosymbiosis of a ______ is thought to have given rise to mitochondria, and later, the endosymbiosis of a ______ bacterium is thought to have given rise to chloroplasts.

proteobacterium; photosynthetic

During Earth's early history, chemical aggregations may have formed and been destroyed by _______, but by around 4 billion years ago, the first ______ were able to survive, reproduce, and diversify.

radiation and space debris; cells

The earliest multicellular fossil was a ______ that lived about 1 billion years ago.

red alga

Select all the proposed reasons for the mass extinction that occurred at the end of the Permian period.

release of toxic hydrogen sulfide by decomposing bacteria volcanic eruptions, causing climate change decreased sea levels increase in carbon dioxide in the atmosphere, thus decreasing available oxygen

Scientists propose that the Golgi apparatus, endoplasmic reticulum, and nuclear envelope may have arisen by

repeated infoldings of the outer cell membrane.

What vertebrate group was the most diverse during the Jurassic period of the Mesozoic era?

reptiles

During the Carboniferous period, some amphibians arose that could lay eggs with hard shells on land. These amphibians gave rise to the first

reptiles.

Select all the conditions present in deep-sea hydrothermal vents that may have favored prebiotic formation of molecules.

rich mineral content dissolved CO2 high pressures extremely hot water meeting cold ocean water

Some researchers suggest that ______ molecules were the first information molecules formed on early Earth.

rna

In photosynthetic protists whose chloroplasts have three or four membranes, the chloroplasts are thought to have arisen by

secondary endosymbiosis

Select all of the global environmental changes that have affected speciation and extinction on Earth.

shifting continents over the Earth's surface advancing and retreating glaciers changing temperatures increased atmospheric oxygen

shoulder joint that allows 360-degree movement

shoulder joint that allows 360-degree movement

Select all of the following that are important features of primate skulls that a paleontologist might study.

size of the jaw bones prominence of the ridge of bone above the eyes shape of the tooth row presence of a sagittal crest

Scientists examining evolutionary relationships of prehistoric humans have most often used comparisons of

skeletal features of fossils.

The oldest known fossils are about 3.7 billion-year-old and resemble formations called ______ made by prokaryotes called ______.

stromatolites; cyanobacteria

What was likely released into the environment by Earth's first photosynthetic organisms, which used H2S as an electron donor?

sulfur

The Miller experiment, also called the first prebiotic simulation, was an attempt to

test whether organic molecules could form from the chemical conditions on early Earth.

What region was last to be colonized by Homo sapiens about 20,000 years ago?

the Americas

Select all of the vertebrates that were present in the Jurassic period of the Mesozoic era.

the first birds the first small mammals marine reptiles pterosaurs, apatosaurs, and stegosaurs sharks and rays giant reptiles

Scientists can determine the type of locomotion used by animals through examination of the foramen magnum,

the hole in the skull where the spinal cord leaves the brain.

The image shows how membrane infolding may have given rise to

the nuclear envelope and endoplasmic reticulum.

Eons, eras, and periods are terms used to define major geological or biological events within Earth's geological .

timesclae

Select all of the following that large teeth with many ridges indicate in a primate fossil.

tough diet grinding function

True or false: Cells do not assemble mitochondria and chloroplasts, which instead divide like bacterial cells.

true

True or false: Earth's surface was frequently exposed to ultraviolet radiation and meteorites during its first 500 to 600 million years.

true

What could a scientist know about a primate's life if its fossil skull had a prominent sagittal crest?

type of diet and strength of the jaws

Select all of the characteristics that may relate to the evolution of a large brain in humans.

use of language living in social groups tool use

The first fossils of ______ are known from the Ordovician period of the Paleozoic era.

vertebrates

The first ______, which were jawless fishes called ostracoderms, arose during the ______ period of the Paleozoic era.

vertebrates; Ordovician

When photosynthetic bacteria began to use ______ as an electron donor in photosynthesis, ______ began to be released and to accumulate in Earth's atmosphere, as evidenced by iron-rich sediments in oceans.

water; oxygen

During the Carboniferous period of the Paleozoic era, the bony fish and sharks that arose during the Devonian

were beginning to resemble modern forms.

The first organisms on Earth

were simpler than any cell known today.