Lab exam 2

Question 1

Special types of cultured media are used for what?

Answer 1

Used to detect or isolate particular organisms

Question 2

1. T or F, Culture media can be liquid or solid?
2. liquid media is called what? Solid media?

Answer 2

1. True
2. Liquid media = broth media
   solid media = broth media w agar

Question 3

*Liquefies at temperatures above 95°C
* Solidifies at 45°C
* Generally not metabolized,

Answer 3

agar

Question 4

what media contains compounds that selectively inhibit growth of some microbes but not others?

Answer 4

selective media

Question 5

Contains substance that allows
distinguishing of colonies of
different microbes on the same
plate

Answer 5

Differential medium

Question 6

T/F Some media have both selective and
differential characteristics

Answer 6

TRUE

Question 7

2 examples of differential media

Answer 7

• Blood agar
  -MacConkey agar

Question 8

When grown on solid media, cells
form what?

Answer 8

Isolated masses (colonies).

Question 9

What is colony morphology used for?

Answer 9

• to identify microorganisms
• to distinguishes cultures (pure, contaminated, or mixed)

Question 10

Q: Amoeba, Trypanosoma, Paramecium, and Euglena are all types of what?

Answer 10

A: Protozoa.

Question 11

What is the formula for pfu/ml

Answer 11

PFU/ml=
Numberofplaques×dilutionfactor
————————————————–
volume of phage saple in mL

Question 12

Name examples of an aerobe, anaerobe, and a facultative anaerobe.

Answer 12

Aerobe: Bacillus subtilis

Anaerobe: Clostridium sporogenes

Facultative anaerobe: Escherichia coli

Question 13

What is a countable plate for bacteriophage plaques?

Answer 13

A plate with 25-250 plaques.

Question 14

What is an anaerobe?

Answer 14

An organism that does not require oxygen for growth and may even die in its presence.

Question 15

Q: What is the phylum for Amoeba? Trypanosoma?
Paramecium?
Euglena?

Answer 15

A: Amoebozoa (sarcodina)

Euglenozoa

Ciliophora

Euglenozoa

Question 16

Q: Identify the domain of Anabaena and its notable feature.

Answer 16

A: Domain Bacteria - Cyanobacteria with heterocysts (used for nitrogen fixation).

Question 17

Q: What is the function of heterocysts in Anabaena (Cyanobacteria)?

Answer 17

A: specialized cells used for nitrogen fixation, allowing Anabaena to convert atmospheric nitrogen into a usable form.

Question 18

Q: Place Saccharomyces, Penicillium, Rhizopus, Morchella, and “mushroom” in their proper phyla (Ascomycota, Basidiomycota, Zygomycota).

Answer 18

Saccharomyces - Ascomycota
Penicillium - Ascomycota
Rhizopus - Zygomycota
Morchella - Ascomycota
“Mushroom” - Basidiomycota

Question 19

What is a GasPak jar.

Answer 19

A sealed jar used to create an anaerobic environment for culturing bacteria.

Question 20

Q: What is the process called when Saccharomyces reproduces asexually?

Answer 20

A: Budding. (forming four haploid zygotes.)

Question 21

Q: Name the three types of lichen growth forms.

Answer 21

A: Crustose, Foliose, Fruticose.

Question 22

Q: What two organisms form a lichen?

Answer 22

A: A fungus and an alga (or cyanobacterium).

Question 23

Q: What is a slide culture used for?

Answer 23

A: Observing the growth and structure of fungi.

Question 24

What is the reaction used in a Gas Pak to remove O₂, and what is the catalyst?

Answer 24

Hydrogen combines with oxygen to form water. The catalyst is palladium.

Question 25

Q: What stain is commonly used on molds?

Answer 25

A: Lactophenol cotton blue.

Question 26

What is the name of the medium used in the enrichment step?

Answer 26

Thioglycolate broth.

Question 27

What is the purpose of the enrichment step?

Answer 27

promote the growth of anaerobic bacteria while suppressing others.

Question 27

Where are paramecium found?

Answer 27

Fresh water and stagnant pools

Question 28

What is the purpose of a selective medium?

Answer 28

allow the growth of specific microorganisms while inhibiting others.

Question 28

What is the length of paramecium?

Answer 28

300 µm

Question 29

Q: Identify sexual and asexual reproductive structures of fungi.

Answer 29

A: Sexual: Zygospores, Ascospores Asexual: Conidiospores, Sporangiospores

Question 30

Q: What is the sexual spore of Zygomycota, and how is it formed?

Answer 30

A: Zygospore; forms from mating type fusion, dark and rough.

Question 31

Q: How does Zygomycota reproduce asexually?

Answer 31

A: By round sporangia containing sporangiospores.

Question 32

Q: Describe Rhizopus reproduction.

Answer 32

A: Forms zygospores sexually and sporangia for asexual spores.

Question 33

Q: What is Rhizopus commonly known as? Q: Where is Rhizopus commonly found? Q: How does Rhizopus reproduce? Q: What are rhizoids in Rhizopus?

Answer 33

A: Black bread mold. A: Growing on bread. A: Both sexually and asexually. A: Root-like structures that attach to food surfaces.

Question 33

How is the shape of Paramecia maintained?

Answer 33

stiff, but elastic pellicle

Question 34

Q: Where are ascospores produced in Ascomycota?

Answer 34

A: In an ascus, which is round or elongated.

Question 34

How do Paramecia move?

Answer 34

by tiny cilia that cover the pellicle

Question 35

Q: How many spores are in an ascus, and how do they form?

Answer 35

A: Eight spores; from meiosis (four) and mitosis.

Question 36

What type of feeders are Paramecia?

Answer 36

They are filter-feeders.

Question 36

Q: What unique structure does Sordaria produce?

Answer 36

A: Perithecium, which contains and releases ascospores.

Question 37

Q: What is Morchella commonly known as? Q: Are Morchella edible, and in which cuisine are they prized? Q: When is Morchella in season, and why are they expensive?

Answer 37

A: True morels. A: Yes, they are prized in French cuisine. A: In the spring; they do not store or transport well.

Question 38

What is the function of the oral groove in Paramecia?

Answer 38

forms a pocket that acts as a scoop to gather food

Question 38

Q: How does Saccharomyces reproduce asexually?

Answer 38

A: By budding.

Question 39

Q: What is Saccharomyces cerevisiae commonly known as? Q: How does Saccharomyces cerevisiae reproduce sexually? Q: What is the asexual reproduction method of Saccharomyces cerevisiae?

Answer 39

A: Baker's yeast or brewer's yeast. A: By forming four haploid zygotes. A: Budding

Question 40

What are cyanobacteria commonly called?

Answer 40

Blue-green algae

Question 41

Q: Name the three main lichen growth forms. Q: What is litmus, and its relation to lichens? Q: What does the color of litmus indicate?

Answer 41

A: Foliose (leaf-like), Fruticose (branch-like), Crustose (flat). A: A pH indicator made from lichen pigments. A: turns red in acid, blue in alkaline.

Question 42

Q: What is Penicillium known for, and how does it reproduce?

Answer 42

A: Produces penicillin and is familiar blue-green kitchen mold; reproduces by asexual spores called conidiospores on conidiophores.

Question 43

Q: Describe Penicillium conidiophores.

Answer 43

A: Stem-like, branches with phialides producing spore chains.

Question 44

Q: How are basidiospores formed?

Answer 44

A: In a basidium, after sexual fusion and meiosis.

Question 45

Q: Name the 4 main mushroom parts and functions.

Answer 45

A: Cap: Produces spores. Stipe: Supports cap. Annulus: Collar under cap. Gills: Produce basidiospores.

Question 46

Q: Where does most of the mushroom fungus grow? Q: What is the ploidy of mycelium from germinated spores? Q: What forms after the fusion of compatible mating types in mushroom fungus?

Answer 46

A: As underground mycelium. A: Haploid. A: Diploid mycelium with dikaryotic cells (separate haploid nuclei).

Question 47

Q: What triggers mushroom formation?

Answer 47

A: Favorable conditions, like cool spring rains

Question 48

Q: What is the movement structure of Amoeba proteus? Q: Where is Amoeba proteus commonly found? Q: How does Amoeba proteus obtain food?

Answer 48

A: Pseudopodia (extensions formed by cytoplasm flow). A: In freshwater. A: Engulfs algae and smaller protozoans.

Question 49

Are cyanobacteria true algae

Answer 49

No, they are bacteria, not true algae

Question 50

What are Anabaena?

Answer 50

cyanobacteria that photosynthesize and can fix nitrogen

Question 51

How is nitrogen fixation accomplished in Anabaena?

Answer 51

through heterocysts

Question 52

What is a practical use for some species of Anabaena?

Answer 52

used to replenish nitrogen in rice paddies

Question 53

Why can some species of Anabaena be harmful

Answer 53

can produce toxins that are harmful to local wildlife

Question 54

(word bank: anoxic, obligate anaerobes, aerotolerant, obligate aerobes, microaerophiles, facultative anaerobes) Obligate _________: absolutely require oxygen – grow at full O2 tension (~21%) and respire O2 ___________ anaerobes: able to grow with or without oxygen – grow via fermentation or anaerobic respiration when oxygen is NOT available ___________ anaerobes: can’t use oxygen and most are harmed by it _____________: can tolerate but can’t use oxygen _________________: can use O2 only at levels reduced from that in air (microoxic) due to limited respiration or oxygen sensitivity ________ (oxygen free) habitats: mud, bogs, marshes, animal intestines, other diverse habitats

Answer 54

Obligate aerobes Facultative anaerobes Obligate anaerobes Aerotolerant Microaerophiles Anoxic

Question 55

Why is oxygen toxic?

Answer 55

forms toxic byproducts inside phagolysosome in phagocytes. (superoxide anion, hydrogen peroxide, peroxide anion, hydroxyl radical)

Question 56

What are the toxic forms of Oxygen ______________ catalyzes this rxn O2 + O2 +2H+ -----> H2O2 + O2 ___________ converts hydrogen peroxide to water and oxyegn H2O2+2H+ -----> 2H2O

Answer 56

Superoxide dismutase Catalase Peroxidase

Question 57

Q: What type of organism is Euglena and how does it move? Q: Can Euglena be autotrophic, heterotrophic, or both? Q: What is the purpose of the "eyespot" in Euglena? Q: What is the size range of Euglena gracilis?

Answer 57

A: A single-celled organism; moves by means of a terminal flagellum. A: Both; it can photosynthesize or absorb soluble nutrients. A: photosensitive; steers the organism toward light for photosynthesis. A: 30-50 µm in length