Organisms

Question 1

How old is Earth?

Answer 1

4.5 billion years

Question 2

How long have microorganisms inhabited the Earth?

Answer 2

3.8 billion years

Question 3

On what basis are organisms placed into the various groups in a classification scheme?

Answer 3

shared evolutionary history

Question 4

What are the three domains that classify all living things?

Answer 4

archaea, bacteria, eukaryotes

Question 5

Which of the three domains contain microorganisms?

Answer 5

all

Question 6

Which of the three domains are prokaryotic?

Answer 6

archaea, bacteria

Question 7

On what basis was it determined that bacteria and archaea should be classified into different domains?

Answer 7

rRNA structural differences

Question 8

What characteristics are shared by bacteria and archaea?

Answer 8

All are prokaryotic, unicellular, and reproduce via binary fission.

Question 9

What characteristics differ between bacteria and archaea?

Answer 9

bacterial cell walls contain peptidoglycan, other structural and chemical differences, many archea are are extremophiles

Question 10

Do fungi represent an evolutionary grouping? Explain.

Answer 10

yes, they are a kingdom, which is a grouping based upon shared evolutionary ancestry.

Question 11

List the general features common to all fungi.

Answer 11

rigid cell walls (generally composed of chitin), chemoheterotrophic (obtain carbon and energy from other organisms), eukaryotic.

Question 12

Are fungi unicellular or multicellular? Explain.

Answer 12

they are dimorphic, meaning they are both unicellular (ex: yeast) and multicellular members (ex: molds and mushrooms)

Question 13

What is a dimorphic fungus?

Answer 13

meaning they are both unicellular (ex: yeast) and multicellular members (ex: molds and mushrooms)

Question 14

How do fungi get their energy?

Question 15

saprobes

Answer 15

organisms that get their energy from other dead organisms

Question 16

pathogens

Answer 16

organisms that get their energy from other live organisms

Question 17

How are fungi important in the environment?

Answer 17

saprobes decompose dead organisms, allowing other organisms to access their nutrients. fungi both produce (ex: fermentation) and destroy food supplies (ex: spoilage) (from a human point of view).

Question 18

How are fungi important to humans?

Answer 18

they spoil food and are responsible for some disease, they also produce fermented food products.

Question 19

mycorrhizae

Answer 19

a beneficial association between fungi and plant roots, formed in roughly 90% of vascular plants, which increases the plants ability to obtain nutrients from soil in return for carbohydrates to the fungi.

Question 20

lichen

Answer 20

a beneficial association between fungi and a photosynthetic algae or bacterium, where the fungi provides nutrients, water, and protection from desiccation; while the algae provides carbohydrates to the fungi.

Question 21

How are fungi similar to bacteria?

Answer 21

both have cell walls and reproduce via binary fission

Question 22

How do fungi differ from bacteria?

Answer 22

cell wall made of peptidoglycan in bacteria, chitin in fungi. fungi are dimorphic while bacteria are unicellular, fungi are eukaryotic while bacteria are prokaryotes.

Question 23

Do algae represent an evolutionary grouping? Explain.

Answer 23

no, they are classified in terms of being eukaryotic organisms that perform oxygenic photosynthesis. no shared evolutionary ancestry.

Question 24

List the general features common to all algae.

Answer 24

rigid cell walls, oxygenic photosynthesis, eukaryotic.

Question 25

Are algae unicellular or multicellular? Explain.

Answer 25

algae exist in unicellular, multicellular, or communal forms (groups of unicellular organisms)

Question 26

How do most protozoa get their energy?

Answer 26

most are heterotrophic, some are photosynthetic autotrophs.

Question 27

Do protozoa represent an evolutionary grouping? Explain.

Answer 27

no, they represent a diverse grouping of unicellular, mostly mobile eukaryotes, not a monophyletic grouping.

Question 28

List the general features common to all protozoa.

Answer 28

protozoa are usually single-celled and heterotrophic eukaryotes containing non-filamentous structures that belong to any of the major lineages of protists. They are restricted to moist or aquatic habitats (i.e., they are obligate aquatic organisms). Many protozoan species are symbionts, some are parasites, and some are predators of faeces bacteria and algae. There are an estimated 30,000 protozoan species.

Question 29

Are protozoa unicellular or multicellular?

Answer 29

unicellular.

Question 30

How do most protozoa get their energy?

Answer 30

most are hetertrophic, some are photosynthetic.

Question 31

How do most protozoa move through their environment?

Answer 31

pseudopodia, flagella, cilia.

Question 32

How are protozoa important to humans?

Answer 32

Some are pathogenic (disease causing).

Question 33

How are protozoans similar to bacteria?

Answer 33

both are unicellular.

Question 34

How do protozoans differ from bacteria?

Answer 34

protozoa are eukaryotes while bacteria are prokaryotes.

protozoa have no cell wall while bactria do.

protozoa may be extremeophiles while bacteria are not.

protozoans are generally larger than bacteria.

protozoa may be multicellular (but generally are not!) while bacteria are not

Question 35

How are protozoans similar to fungi?

Answer 35

both are eukaryotic, both can reporduce sexually or asexually, both may exist in unicellular or multicellular forms.

Question 36

How do protozoans differ from fungi?

Answer 36

most protozoans are motile (capable of motion),