Paleontologists have found fossils dating back 3.6 billion years. These closely resemble

Paleontologists have found fossils dating back 3.6 billion years. These closely resemble

small invertebrate animals.

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nothing alive today.

fungi.

today’s simplest plants.

blue-green algae present today.

5 points

QUESTION 2

When taxonomists classify organisms using a phylogenetic approach, they are most concerned with

outgroups.

cladists.

ingroups.

ancestral traits.

derived traits.

5 points

QUESTION 3

In bacteria, the cell wall is composed mainly of

various polysaccharides.

peptidoglycans.

proteins.

glycoproteins.

lipids.

5 points

QUESTION 4

Which form of bacterial cells is rod shaped?

cocci

vibrios

spirilla

rhodius

Bacilli

5 points

QUESTION 5

The endosymbiont hypothesis suggests that the mitochondria of eukaryotic cells are descended from captured

cyanobacteria.

eukaryotic algae.

chemoautotrophic bacteria.

archaebacteria.

aerobic bacteria.

5 points

QUESTION 6

Eukaryotic cells are thought to have

evolved before prokaryotic cells.

appeared about 2.1 billion years ago.

first appeared with tough cell walls.

first appeared as parts of multicellular organisms.

developed when mitochondria grew much larger in size that they had been previously.

5 points

QUESTION 7

What term is used to indicate a characteristic that is shared and inherited from a common ancestor?

analogous trait

homologous trait

cladistic trait

outgroups

derived trait

5 points

QUESTION 8

Prions are composed of

DNA, RNA, and protein.

protein.

DNA and protein.

DNA.

RNA.

5 points

QUESTION 9

Of the following, which kingdom contains the most diversity in terms of DNA sequences?

All of these are approximately equivalently diverse.

Protista

Fungi

Plantae

Animalia

5 points

QUESTION 10

Atmospheric chemists think that Earth’s first atmosphere

contained no oxygen atoms.

consisted of carbon in the form of carbon dioxide.

was very similar to today’s atmosphere.

consisted of carbon in the form of carbon monoxide.

contained nitrogen in the form of ammonia and nitrogen gas.

5 points

QUESTION 11

Rickettsias belong to which major group of bacteria?

Archaea

cyanobacteria

spirochetes

viruses

Proteobacteria

5 points

QUESTION 12

The Cambrian Explosion provided a wealth of fossil remains for scientists to uncover. Many of the animals from this time period had tough skins or shells. This would

make these animals more desirable to predators.

be a disadvantage for these organisms and lead to their death and fossil formation.

allow the animals to move into different environments easily.

protect the animal from osmotic pressure.

protect the animal from predators.

5 points

QUESTION 13

What is the main difference between protists and bacteria?

Bacteria are always gram-negative, protists are gram-positive

Bacteria have DNA, protists do not.

Protists have a nucleus, bacteria do not

Protists cannot cause infections, bacteria can

Protists are unicellular, bacteria are multicellular.

5 points

QUESTION 14

Most bacteria are

chemoautotrophs.

symbionts.

photoautotrophs.

microbial predators.

heterotrophs.

5 points

QUESTION 15

Oxygen built up in the atmosphere approximately 2 billion years ago and

occurred because aerobic organisms required the oxygen.

destroyed ozone forming more oxygen.

could not have occurred without the oxygen coming from outer space.

helped to form the ozone layer that is so important to life today.

occurred due to carbon dioxide being split by lightning strikes.

5 points

QUESTION 16

Endospores form

to produce two offspring from every one parental cell.

as a means of genetic recombination.

when the environmental conditions are favorable.

in response to adverse conditions.

during binary fission.

5 points

QUESTION 17

Kelps are a form of what group of protists?

ciliates

dinoflagellates

water molds

slime molds

brown algae

5 points

QUESTION 18

All but one of the following are false regarding protists. Identify the true statement.

Protists do not have the ability to move on their own.

All protists are single-celled organisms.

Protists are prokaryotic.

Most protists are single-celled organisms; some are multicellular.

Protists have cell walls composed mainly of peptidoglycans.

5 points

QUESTION 19

During which geological era did Pangea break apart?

Archean

Paleozoic

Cenozoic

Mesozoic

Proterozoic

5 points

QUESTION 20

Some bacteria can form resting structures called ___________ that can withstand extremes in temperature, moisture, and radiation.

endospores

capsids

prions

viroids

symbionts