QUESTION 1 Which form of bacterial cells is rod shaped? vibrios rhodius spirilla

Question

QUESTION 1

Which form of bacterial cells is rod shaped?

vibrios

rhodius

spirilla

cocci

bacilli

5 points   

QUESTION 2

Prions are composed of

protein.

DNA and protein.

RNA.

DNA.

DNA, RNA, and protein.

5 points   

QUESTION 3

Most bacteria are

heterotrophs.

microbial predators.

photoautotrophs.

symbionts.

chemoautotrophs.

5 points   

QUESTION 4

In bacteria, the cell wall is composed mainly of

various polysaccharides.

lipids.

glycoproteins.

peptidoglycans.

proteins.

5 points   

QUESTION 5

Rickettsias belong to which major group of bacteria?

spirochetes

cyanobacteria

proteobacteria

viruses

Archaea

5 points   

QUESTION 6

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

cladists.

outgroups.

ingroups.

derived traits.

ancestral traits.

5 points   

QUESTION 7

Eukaryotic cells are thought to have

appeared about 2.1 billion years ago.

evolved before prokaryotic cells.

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

first appeared with tough cell walls.

first appeared as parts of multicellular organisms.

5 points   

QUESTION 8

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

blue-green algae present today.

nothing alive today.

today’s simplest plants.

small invertebrate animals.

fungi.

5 points   

QUESTION 9

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

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

make these animals more desirable to predators.

allow the animals to move into different environments easily.

protect the animal from osmotic pressure.

protect the animal from predators.

5 points   

QUESTION 10

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

outgroups

analogous trait

cladistic trait

homologous trait

derived trait

5 points   

QUESTION 11

Kelps are a form of what group of protists?

water molds

brown algae

slime molds

ciliates

dinoflagellates

5 points   

QUESTION 12

What is the main difference between protists and bacteria?

Protists have a nucleus, bacteria do not

Protists are unicellular, bacteria are multicellular.

Protists cannot cause infections, bacteria can

Bacteria have DNA, protists do not.

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

5 points   

QUESTION 13

During which geological era did Pangea break apart?

Paleozoic

Proterozoic

Archean

Cenozoic

Mesozoic

5 points   

QUESTION 14

Atmospheric chemists think that Earth’s first atmosphere

contained nitrogen in the form of ammonia and nitrogen gas.

contained no oxygen atoms.

consisted of carbon in the form of carbon monoxide.

consisted of carbon in the form of carbon dioxide.

was very similar to today’s atmosphere.

5 points   

QUESTION 15

Endospores form

in response to adverse conditions.

to produce two offspring from every one parental cell.

when the environmental conditions are favorable.

during binary fission.

as a means of genetic recombination.

5 points   

QUESTION 16

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

Protists are prokaryotic.

Protists have cell walls composed mainly of peptidoglycans.

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

All protists are single-celled organisms.

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

5 points   

QUESTION 17

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

Protista

Plantae

All of these are approximately equivalently diverse.

Animalia

Fungi

5 points   

QUESTION 18

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

aerobic bacteria.

chemoautotrophic bacteria.

eukaryotic algae.

archaebacteria.

cyanobacteria.

5 points   

QUESTION 19

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

destroyed ozone forming more oxygen.

occurred due to carbon dioxide being split by lightning strikes.

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 because aerobic organisms required the oxygen.

5 points   

QUESTION 20

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

symbionts

endospores

viroids

prions

capsids

A.

vibrios

B.

rhodius

C.

spirilla

D.

cocci

E.

bacilli

Explanation / Answer

1. Option E. Bacilli...Vibrio : comma shaped bacteria. Eg: Vibrio cholerae ;Spirilla : Spiral shaped bacteria. Eg: Treponema pallidum, ;Cocci: spherical, oval shaped bacteria; Eg: Streptococcus pneumoniae. Bacilli: Rod shaped bacteria. Eg E.coli. Bacillus anthracis.

2. Option A. Protein. Prions (Pr:Protein, ion: Infection). contain only proteins and lack DNA or RNA. They cause Mad cow disease.

4. Option D.

5. Rickettsiae: Option C. Proteobacteria. They are gram negative, non spore forming which are obligate intracellular parasites. They cause the disease Rocky mountain spotted fever.

11. Option B. brown algae. Kelps are brown algae.sea weeds, brown algae.

12. Option A Bacteria donot contain well defined nucleus.

15. Option A. in response to adverse conditions. Endospores are dormant, non reproductive structures formed when conditions are not favourable which are resistant to harsh climatic conditions by gram positive bacteria. Endospores ensure the survival of bacteria during harsh environmental conditions. Eg: Bacillus sp and Clostridium sps. During favorable condition they sporulate

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

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