Diversity of microbes, fungi, and protists

Question 1

What were the first forms of life on Earth?

Answer 1

prokaryotes

Question 2

Anoxic

Answer 2

No oxygen-this was the Earth’s atmosphere in the beginning.

Question 3

Anaerobic

Answer 3

Organisms that grow without oxygen

Question 4

Phototrophs

Answer 4

Organisms that convert solar energy into chemical energy

Question 5

What life appears within the first billion years on Earth?

Answer 5

Phototrophic organisms that required an organic source of carbon -phototrophs

Question 6

What life evolved from phototrophs in the second billionth year on Earth?

Answer 6

cyanobacteria

Question 7

Cyanbobacteria

Answer 7

Blue-green algae

Question 8

What bacteria began the oxygenation process?

Answer 8

cyanobacteria

Question 9

Microbial Mat

Answer 9

a large biofilm, a multi-layered sheet of prokaryotes, including mostly bacteria, but also archaea. 3.5 billion years ago.

Question 10

What are the characteristics of microbial mats?

Answer 10

few centimeters thick, grow on moist surfaces, carryout different metabolic processes, different colors, held together by gummy substance

Question 11

Hydrothermal vent

Answer 11

a fissure in Earth’s surface that releases geothermally heated water.

Question 12

Stromatolite

Answer 12

stromatolite is a sedimentary structure formed when minerals are precipitated from water by prokaryotes in a microbial mat -they form layered rocks made of carbonate or silicate.

Question 13

extremophiles

Answer 13

Bacteria and archaea that grow under extreme conditions -lover of extremes

Question 14

Biofilm

Answer 14

a microbial community held together by a gummy-like secretion -it is made of polysaccharides, some proteins and nucleic acids.

Question 15

Characteristics of a biofilm

Answer 15

can live on any surface, clog pipes, involved in large bacterial outbreaks on food, robust and difficult to destroy.

Question 16

What four structures do all cells have in common?

Answer 16

Plasma membrane, cytoplasm, genetic material as DNA and RNA, and ribosomes.

Question 17

What three shapes do prokaryotes fall in?

Answer 17

cocci (spherical), bacilli (rod-shaped), and spirilla (spiral-shaped)

Question 18

What are prokaryotes?

Answer 18

Unicellular organisms without organelles surrounded by membranes -no nucleus, DNA in nucleoid.

Question 19

Bacteria and Archaea are…?

Answer 19

prokaryotes with simple structures but different chemical structures -archaea sometimes have lipid monolayers.

Question 20

Bacterial cell walls contain…?

Answer 20

peptidoglycan

Question 21

Peptidoglycan

Answer 21

is made of polysaccharide chains cross-linked to peptides.

Question 22

What two groups are bacteria divided into?

Answer 22

Gram-positive and Gram-negative

Question 23

Gram-positive

Answer 23

Gram-positive organisms have a thick wall made of many layers of peptidoglycan.

Question 24

Gram-negative

Answer 24

Gram-negative bacteria have a thinner cell wall with a few layers of peptidoglycan and additional structures, surrounded by an outer membrane

Question 25

Archaeal cell walls…

Answer 25

do not contain peptidoglycan.

Question 26

What are the four different types of archaeal cell walls made of?

Answer 26

Pseudopeptidoglycan, polysaccharides, glycoproteins, and surface-layer proteins or S-layers.

Question 27

Reproduction in prokaryotes is…?

Answer 27

asexual and uses binary fission (not mitosis)

Question 28

Binary fission

Answer 28

the chromosome loop is replicated, and the two resulting copies attached to the plasma membrane move apart as the cell grows

Question 29

What are the three ways that prokaryotes can alter their genetic makeup?

Answer 29

Transformation, transduction, conjugation

Question 30

Transformation

Answer 30

the cell takes in DNA found in its environment that is shed by other prokaryotes, alive or dead, or pathogen.

Question 31

Transduction

Answer 31

(bacteriophages) the viruses that infect bacteria, move DNA from one bacterium to another.

Question 32

Conjugation

Answer 32

DNA is transferred from one prokaryote to another by a pilus that brings the organisms into contact with one another. The DNA is usually a plasmid, but parts of the chromosome can also be moved.

Question 33

What niches do prokaryotes fill?

Answer 33

Nutrient cycles (nitrogen and carbon cycles), decomposition of organisms, growing and multiplying inside organisms.

Question 34

All pathogenic prokaryotes are…

Answer 34

bacteria (no known pathogenic Archaea)

Question 35

Zoonosis

Answer 35

A disease that can be transferred from animals to humans.

Question 36

Botulism

Answer 36

potentially fatal disease produced by a toxin from the anaerobic bacterium Clostridium botulinum

Question 37

Food poisoning

Answer 37

is an illness resulting from the consumption of food contaminated with pathogenic bacteria, viruses, or other parasites.

Question 38

Bioremediation

Answer 38

Microbial bioremediation is the use of prokaryotes (or microbial metabolism) to remove pollutants.

Question 39

Bioremediation has been used to…?

Answer 39

remove pesticides and fertilizers from soil, toxic metals from water (selenium and water), oil spills,

Question 40

Commensalism

Answer 40

a type of relationship in which the bacterium benefits and the human host is neither benefited nor harmed.

Question 41

Prokaryotes (bacteria and archaea) that live in humans help…?

Answer 41

metabolism of food molecules that we cannot break down, assistance with the absorption of ions by the colon, synthesis of vitamin K, training of the infant immune system, maintenance of the adult immune system, maintenance of the epithelium of the large intestine, and formation of a protective barrier against pathogens.