Chapter 25

Question 1

Earth’s early atmosphere had little oxygen and likely contained water vapor and chemicals released by volcanic eruptions, give examples of the gasses released by these volcanic eruptions

Answer 1

Nitrogen, Carbon dioxide, Methane, Ammonia, Hydrogen

Question 2

In the 1920s, they independently hypothesized that the early atmosphere was a reducing environment

Answer 2

Oparin and Heldane

Question 3

In 1953, They conducted lab experiments demonstrating that the abiotic synthesis of organic molecules in a reducing atmosphere was possible

Answer 3

Stanley Miller and Harold Urey

Question 4

Areas on the seafloor where hot water and minerals gush from Earth’s interior into the ocean

Answer 4

Hydrothermal Vents

Question 5

Release water with high pH (9-11) and warm water (40-90°C)

Answer 5

Alkaline Vents

Question 6

Have been produced spontaneously from simple molecules

Answer 6

RNA Monomers

Question 7

Polymerize when they are concentrated on hot sand, clay, or rock

Answer 7

Small Organic Molecules

Question 8

Replication and metabolism are key properties of life and may have appeared together in?

Answer 8

Protocells

Question 9

May have formed from fluid-filled vesicles with a membrane-like structure

Answer 9

Protocells

Question 10

a soft mineral clay common on early Earth, greatly increases the rate of vesicle formation

Answer 10

Montmorilonite

Question 11

The first genetic material was probably?, not DNA

Answer 11

RNA

Question 11

exhibit simple growth, reproduction, and metabolism

can “reproduce” on their own, and they can increase ins size without dilution of their contents

can absorb montmorillonite particles, including on which RNA and other organic molecules have become attached

Answer 11

Vesicles

Question 12

are deposited into layers called strata and are the richest source of fossils

Answer 12

Sedimentary Rocks

Question 12

have been found to catalyze many different reactions

Answer 12

Ribozymes

Question 13

The fossil record is biased in favor of species that?

Answer 13

• existed for a long time
• were abundant and widespread
• had hard parts, such as shells or skeletons

Question 14

The age of a fossil can be determined using?

Answer 14

Radiometric Dating

Question 14

the time required for half the parent isotope to decay

Answer 14

Half-life

Question 15

Radiocarbon dating can be used to date fossils up to how many years old?

Answer 15

75,000 years old

Question 15

The age of some fossils can be estimated by measuring the ratio of the radioactive isotope ________ to the stable isotope _______

Answer 15

Carbon 14 and 12

Question 16

Mammals belong to the group of animals called?

Answer 16

Tetrapods

Question 17

is divided into the Hadean, Archaean, Proterozoic, and Phanerozoic eons

Answer 17

Geologic Records

Question 18

The geologic records is divided into 4 periods what are these?

Answer 18

Hadean, Archaean, Proterozoic, and Phanerozoic eons

Question 19

The oldest known fossils

rocks formed by the accumulation of sedimentary layers on bacterial mats

Date back to 3.5 billions years ago

Answer 19

Stromatolites

Question 20

were Earth’s sole inhabitants for more than 1.5 billion years

Answer 20

Prokaryotes

Question 21

O2 accumulated gradually in the atmosphere from about how many years ago? and then rapidly shot up to what percentage to the present level

Answer 21

2.4-2.7 billion years ago, 1%-10%

Question 21

caused the extinction of many prokaryotic groups

Answer 21

Oxygen Revolution

Question 22

The oldest fossils of eukaryotic cells date back to how many years ago?

Answer 22

1.8 billion years ago

Question 23

when a prokaryotic cell engulfed a small cell that would evolve into a mitochondrion

Answer 23

Endosymbiosis

Question 24

is a cell that lives within a host cell

Answer 24

Endosymbiont

Question 25

supposes that mitochondria evolved before plastids through a sequence of endosymbiotic events

Answer 25

Serial Endosymbiosis

Question 26

likely descended from bacterial cells; the original host is thought to be an archaean or close relative

Answer 26

Mitochondria and Plastids

Question 27

were an assemblage of larger and more diverse soft-bodied organisms that lived from 635 to 541 million years ago

Answer 27

Ediacaran Biota

Question 28

refers to the sudden appearance of fossils resembling modern animal phyla in the Cambrian period (535 to 525 million years ago)

Answer 28

Cambrian Explosion

Question 29

began to colonize land about 500 million years ago

Answer 29

Fingi, Plants and Animals

Question 30

are the most widespread and diverse land animals

Answer 30

Arthropods and Tetrapods

Question 31

evolved from lobe-finned fishes around 365 million years ago

Answer 31

Tetrapods

Question 32

According to this theory, Earth's crust is composed of plates floating on Earth's mantle

Answer 32

Theory of plate tectonics

Question 33

At times, the rate of extinction has increased dramatically and caused a? can change the types of organisms found in ecological communities

Answer 33

Mass extinction

Question 34

defines the boundary between the Paleozoic and Mesozoic eras 252 million years ago

Answer 34

Permian Extinction

Question 35

A number of factors might have contributed to the Permian mass extinction, what are these?

Answer 35

Extreme Volcanism, Huge amounts of CO2, Anoxomic Conditions

Question 36

occurred 66 million years ago More than half of all marine species, many families of terrestrial plants and animals, and all of the dinosaurs, except birds, went extinct during this event

Answer 36

Cretaceous Mass extinction

Question 37

Data suggest that a sixth, mass extinction is likely to occur unless dramatic action is taken, what is this mass extinction?

Answer 37

Human-cause