College Biology Chapter 21

volcanic activity, lightning, and radiation

High energy sources on early Earth, which were most likely involved in the origin of life, included:

Ordovician period

Shallow seas covered much of the land during the:

survival of cyanobacteria

The appearance of air breathing organisms was most dependent upon:

4.6 billion years

The approximate age of the Earth is:

ozone

The atmospheric gas that prevents the majority of the sun's ultraviolet radiation from penetrating to the Earth's surface is:

similar to the sulfur bacteria of today

The earliest photosynthetic autotrophs were probably:

3.1 to 3.5 billion years ago

The earliest photosynthetic organisms arose about:

utilized organic molecules and did not need oxygen

The first cells were most likely heterotrophic anaerobes because they:

heterotrophic anaerobes

The first cells were probably:

ribozymes

The first enzymes were probably

were small and jawless

The first fish:

arthropods

The first land animals were probably the:

cyanobacteria

The first organisms to release oxygen by photosynthesis were:

the extinction of marine species

The greatest mass extinction of all time, which occurred at the end of the Permian period resulted in:

prebiotic soup hypothesis

The hypotheses that organic molecules formed near the Earth's surface in pools of water is called the:

iron sulfur world hypothesis

The hypothesis that organic molecules formed near deep sea hydrothermal vents is called the:

dramatic climate changes

The mass extinction at the end of the cretaceous period was likely the result of:

synthesized organic molecules

The most significant outcome of the Miller and Urey experiment was that they:

oxygen

The results of the experiment represented in the accompanying figure and similar experiments include the formation of all of the following except:

eukaryotes

The theory illustrated by Figure 21-1 is used to explain the origin of:

presence of DNA

The theory illustrated in Figure 21-1 is supported by which piece of additional evidence?

endosymbiont theory

The theory that eukaryotic organelles originated as prokaryotes that survived ingestion by a host cell and ultimately evolved mutualistic relationships with the host cell is termed the:

cambrian period

The time in the history of the earth when evolution was progressing at the most rapid rate, as evidenced by fossils such as those of the Burgess Shale, is the:

3.5 billion years ago

There is evidence that life existed about:

Silurian period

Vascular plants and air-breathing animals first appeared during the:

oxygen

Which of the following gases was not present in the Earth's early atmosphere but appeared after the evolution of certain organisms?

oxygen

Which of the following is not one of the requirements that must have existed for the chemical evolution of life on Earth to have occurred?

they were slow moving

Which of the following statements about dinosaurs is false?

fishes

Amphibians evolved directly from what ancestral organisms?

oxygen

A compound that could not have been present in the early atmosphere, because it is quite reactive and would have broken down organic molecules that were a necessary step in the origin of life on Earth, is:

ozone

A significant reduction in the amount of which gas would allow more ultraviolet radiation to reach the earth's surface?

enlarged sharp claws

All of the following characteristics apply to the organism in Figure 21-2 except?

hydrogen, methane, water, ammonia

Amino acids and other organic molecules were formed in the laboratory of Miller and Urey from which of the following?

era

Among the following, which is the longest unit of geological time?

protobionts

Assemblages of abiotically produced polymers are called:

stromatolites

Cyanobacteria can be found in columns of fossils referred to as:

amniote egg

During the Oligocene epoch, specializations in mammals that are suggestive of a more open type of habitat include all of the following except the:

Paleocene

During the _____ epoch, the mammals experienced an explosive adaptive radiation.

fluctuating climates

During the pleistocene epoch, plant communities changed dynamically in response to:

RNA can evolve to catalyze reactions

Experiments called in vitro evolution or directed evolution have shown that:

carboniferous period

Great swamp forest covered the globe and formed the major coal deposits during the:

oxygen gas

In the process of splitting water during photosynthesis, the first cyanobacteria released:

RNA molecules can catalyze reactions

It has been suggested that RNA was the first informational molecule to evolve because:

cells and simple organisms

Precambrian rocks contain fossils of:

DNA and RNA

Macromolecules that are capable of self-replication are:

carboniferous period

Mammal-like reptiles arose during the:

600 million years ago

Multicellular eukaryotes arose about:

have been buried deeply

Not much physical evidence of life is available from rocks of the precambrian because these ancient rocks:

rocks and clay

Presently, it is thought that organic polymers may have formed and accumulated on:

molecules to accumulate

One critical requirement for life to arise on Earth was time for:

molecular reproduction

One of the most significant steps in the evolution of true cells from macromolecular assemblages was the evolution of:

ediacarian fossils

One source of fossil organisms in Precambrian rock formations is:

obligate anaerobes

Organisms whose metabolic processes are harmed by the presence of oxygen are called:

mesozoic era

Reptiles dominated the:

disorganization

Some protobionts have been shown to have all of the following features except:

Devonian period

The "Age of Fishes" is an informal name for the:

reptiles

The Cenozoic is often referred to as the age of all the following except:

reducing

The Earth's early atmosphere was probably strongly:

reptiles

The Mesozoic era is often called the age of:

ichthyosaur

The animal in Figure 21-2 represents an: