Chapter 17 practice test

What prevents organic molecules from forming on their own and remaining intact today?

Atmospheric oxygen is too reactive

Why did the development of sexual reproduction speed up the process of evolution?

Sexual reproduction increases genetic variety

What was the response of the various groups of early organisms that existed when oxygen levels rose in the atmosphere

Some life forms became extinct, Some life forms survived in only a few airless habitats, Some life forms evolved metabolic pathways that used oxygen for respiration (all of the above)

What do proteinoid microspheres have in common with cells

They can store and release energy

Earth's most recent era is the

Cenozoic

Why did oceans not exist on Earth nearly 4 billion years ago

Water remained a gas because Earth was very hot

A very large mass extinction in which trilobites and amphibians disappeared occurred at the end of the

Paleozoic Era

A single species that has evolved into several different forms that live in different ways has undergone

adaptive radiation

The Mesozoic Era occurred

after the Paleozoic Era.

Examples of fossils include preserved

all of the above

Which of the following was NOT characteristic of Earth before the oceans formed

an atmosphere containing oxygen gas

The first organisms on Earth were most like today's

bacteria

In the past, mass extinctions encouraged the rapid evolution of surviving species

by making new habitats available to them

Which of the following functions can RNA perform under certain conditions

catalyzing chemical reactions, processing messenger RNA after transcription &helping DNA replicate (all of the above)

The process by which two species, for example, a flower and a pollinating insect, evolve in response to each other is called

coevolution

Sharks, dolphins, and penguins all have streamlined bodies and appendages that enable them to move through water. These similarities are the result of

convergent evolution

. Early in Earth's history, while the planet was in a melted state, the most dense elements formed Earth's

core

During the Jurassic and Cretaceous periods, the dominant land animals were

dinosaurs

The basic divisions of the geologic time scale from larger to smaller are

eras and periods

The length of time required for half of the radioactive atoms in a sample to decay is its

half-life

Two gases that probably existed in Earth's early atmosphere are

hydrogen cyanide and carbon monoxide

To compare the relative ages of fossils, scientists sometimes use an easily recognized species called a(an)

index fossil

In addition to hydrogen, two of the gases used in Miller and Urey's experiment were

methane and ammonia

What proportion of all species that ever lived has become extinct?

more than 99 percent

The Cambrian Explosion resulted in the evolution of the first

representatives of most animal groups

When oxygen was first released in the early seas, it combined with iron to form

rust

Most fossils form in

sedimentary rock

To be useful as an index fossil, a species must have existed for a

short period over a wide geographic range

Sedimentary rock is formed from

small particles of sand, silt, and clay.

One necessary condition for the evolution of the first life on Earth was

the presence of liquid water