CHAPTER 7 REVIEW QUESTIONS: 1.
The thermal death time for a suspension of Bacillus subtilis endospores is 30 minutes in dry heat and less than 10 minutes in an autoclave. Which type of heat is more effective? Why?
Autoclave. Because of the high specific heat of water, moist heat is readily transferred to cells.
2.
If pasteurization does not achieve sterilization, why is pasteurization used to treat food?
Pasteurization destroys most organisms that cause disease or rapid spoilage of food.
3. Variables that that affect determination of the thermal death point are?
•
The innate heat resistance of the strain of bacteria.
•
The past history of the culture, whether it was freeze-dried, wetted, etc.
•
The clumping of the cells during the test
•
The amount of water present
•
The organic matter present
•
Media and incubation temperature used to determine viability of the culture after heating.
4. The antimicrobial effect of gamma radiation is due to (a) _______. The antimicrobial antimicrobial effect of ultraviolet radiation is due to (b) _______ .
a.
The ability of ionizing radiation to break DNA directly. However, because of the high water content of cells, free radicals (H and OH) that break DNA strands are likely to form.
b. Formation of thymine dimmers.
5. How do you autoclaving, hot air, and pasteurization illustrate the concept of equivalent treatments?
All three processes kill microorganisms; however, as moisture and/or temperatures are increased, less time is required to achieve the same result.
6.
How do salts and sugars preserve foods? Why are these considered physical rather than chemical methods of microbial control? Name one food that is preserved with sugar and one preserved with salt. How do you account for the occasional growth of Penicillium mold in jelly, which is 50% sucrose?
Salts and sugars create a hypertonic environment. Salts and sugars (as preservatives) do not directly affect cell structures or metabolism; instead, they alter the osmotic pressure. Jams and jellies are preserved with sugar; meats are usually preserved with salt. Molds are more capable of growth in high osmotic pressure than are bacteria.
7. The use-dilution values for two disinfectants A- 1:2; Disinfectant B-1:10,000. If both disinfectants are designed for the same purpose, which would you select? Disinfectant B is preferable because it can be diluted more and still be effective.
8. A large hospital washes burn patients in a stainless steel tub. After each pt, the tub is cleaned w/a quad. It was noticed that 14 of 20 burn pts acquired Pseudomonas infections after being bathed. Provide an explanation for this high rate of infection. Quaternary ammonium compounds are most effective against gram-positive bacteria. Gram-negative bacteria that were stuck in cracks or around the drain of the tub would not have been washed away when the tub was cleaned. These gram-negative bacteria could survive the washing procedure. Some pseudomonads can grow on quats that have accumulated.
MULTIPLE CHOICES: 1.
Which of the following does not kill endospores?
PASTEURIZATION
2. Which of the following is most effective for sterilizing mattresses and plastic Petri dishes?
ETHYLENE OXIDE
3.
Which of these disinfectants does not act by disrupting the plasma membrane?
HALOGENS
4.
Which of the following cannot be used to sterilize a heat-labile solution stored in a plastic container?
AUTOCLAVING
5.
Which of the following is not a characteristic of quaternary ammonium compounds?
SPORICIDAL
6.
A classmate is trying to determine how a disinfectant might kill cells. You observed that when he spilled the disinfectant in your reduce d litmus milk, the litmus turned blue again. You suggest to your classmate that.
THE DISINFECTANT MIGHT OXIDIZE MOLECULES.
7.
Which of the following is most likely to be bactericidal?
IONIZING RADIATION
8.
Which of the following is used to control microbial growth in foods?
ORGANIC ACIDS
9.
Which disinfectant is the most effective?
DISINFECTANT A 1:2 NG, 1:4 NG, 1:8 NG, 1:16 G
10. Which
disinfectant(s) is (are) bactericidal? A, C AND D PG 208
CHAPTER 10
MULTIPLE CHOICES: 1.
Bergey’s Manual of Systematic Bacteriology differs from Bergey’s Manual of Determinative Bacteriology in that the former.
GROUPS BACTERIA ACCORDING TO PHYLOGENERTIC RELATIONSHIPS
2.
Bacillus and Lactobacillus are not in the same order. This indicates that which one of the following is not sufficient to assign an organism to a taxon ?
MORPHOLOGICAL CHARACTERISTICS
3.
Which of the following is used to classify organisms into the Kingdom Fungi?
ABSORPTIVE; POSSESS CELL WALL; EUKARYOTIC
4. Which of the following is not true about scientific nonmenclature?
NAMES VARY WITH GEOGRAPHICAL LOCATION
5.
You could identify an unknown bacterium by all the following except?
6. PERCENTAGE OF GUANINE + CYTOSINE
7.
The wall-less mycoplasma are considered to be related to gram-positive bacteria. Which of the following would provide the most compelling evidence for this?
THEY SHARE COMMON rRNA sequences.
8. Into which group would you place a multicellular organism that has a mouth and lives inside the human liver?
ANIMALIA
9. Into which group would you place a photosynthetic organism that lacks a nucleus and has a thin peptidoglycan wall surrounded by an outer membrane?
PROTEOBACTERIA (GRAM-NEGATIVE BACTERIA)
10. Which is (are) found in all three domains.
70S RIBOSOME PLASMA MEMBRANE
11. Which is (are) found only in prokaryotes?
FIMBRIA PEPTIDOGLYCAN
CHAPTER 11 STUDY QUESTIONS:
1. The following outline can be used to identify important bacteria. Fill in a representative genus in the space provided.
I.
Gram-positive A. Endospore-forming rod 1.
Obligate anaerobe (a) Clostridium
2.
Not obligate anaerobe (b) Bacillus
B. Non-endospore-torming
1. Cells are rods a.
Produce conidiospores (c) Streptomyces
b.
Acid-fast (d) Mycobacterium
2. Cells are cocci
II.
a.
Lack cytochrome system (e) Streptococcus
b.
Use aerobic respiration (f) Staphylococcus
Gram-negative A. Cells are helical or curved 1.
Axial filament (g) Treponema
2.
No axial filament (h) Spirillum
B. Cells or rods 1.
Aerobic, nonfermenting (i) Pseudomonas
2.
Facultatively anaerobic (j) Escherichia
III.
Lack of cell walls (k) Mycoplasma
IV.
Obligate intracellular parasites A.
Richettsia Transmitted by ticks (l)
B.
Reticulate bodies in the host cells Chlamydia (m)
2. Compare and contrast each of the following: A.) Cyanobacteria and algae Both are oxygenic photoautotrophs. Cyanobacteria are prokaryotes; algae are eukaryotes.
B.) Actinomycetes and fungi Both are chemoheterotrophs capable of forming mycelia; some form conidia. Actinomycetes are prokaryotes; fungi are eukaryotes.
C.) Bacillus and Lactobacillus Both are large rod-shaped bacteria. Bacillus forms endospores; Lactobacillus is a fermentative non-endospore-forming rod.
D.) Pseudomonas and Escherichia Both are small rod- shaped bacteria. Pseudomonas has an oxidative metabolism; Escherichia is fermentative. Pseudomonas has polar flagella; Escherichia has peritrichous flagella.
E.) Leptospira and Spirillum Both are helical bacteria. Leptospira (a spirochete) has an axial filament. Spirillum has flagella.
F.) Escherichia and Bacteroides Both are gram-negative, rod-shaped bacteria. Escherichia are facultative anaerobes and Bacteroides are anaerobes.
G.) Richettsia and ChlamydiaBoth are obligatory intracellular parasites. Richettsia are transmitted by ticks; Chlamydia has a unique developmental cycle. H.) Ureaplasma and Mycoplasma Both lack peptidoglycan cell walls. Ureaplasma are archaea; Mycoplasma is bacteria.
MULTIPLE CHOICES: 1.
If you Gram-stained the bacteria that live in the human intestine, you would expect to find mostly?
Gram-negative, nitrogen-fixing bacteria
2. Which of the following does not belong with the others?
Lactobacillales
3.
Pathogenic bacteria can be?
Motile, Rods, Cocci, and Anaerobic
4.
Which of the following is an intracellular parasite?
Richettsia
5. Which of the following terms is the most specific?
Bacillus
6.
Which one of the following does not belong with the others?
Staphylococcus
7.
Which of the following pairs is mismatched?
Spirochete- Helicobacter
8.
Spirillum is not classified as a spirochete because spirochets?
Posses’ axial filaments
9.
When Legionella was newly discovered, it was classified with the pseudomonads because?
It is an aerobic gram-negative rod.
10. Cyanobacteria differ from purple and green phototrophic bacteria because Cyanobacteria?
Produce oxygen during photosynthesis
CHAPTER 12
REVIEW QUESTIONS:
1. Following a list of fungi, their methods of entry into the body, and sites of infections they cause. Categorize each type of mycosis as Cutaneous, opportunistic, subcutaneous, superficial, or systemic.
Genus
Method of Entry
Site of Infection
Mycosis
Blastomyces
Inhalation
Lungs
(a) Systemic
Sporothrix
Puncture
Ulcerative lesions
(b) Subcutaneous
Microsporum
Contact
Finger nails
(c) Cutaneous
Trichosporon
Contact
Hair shafts
(d) Superficial
Aspergillus
Inhalation
Lungs
(e) Systemic
2. A mixed culture of Escherichia Coli and Penicillium chrysogenum is inoculated onto the following culture media. On which medium would you expect each to grow? Why? a.
0.5% peptone in tap water (E. COLI)
b.
10% glucose in tap water
(P. CHRYSOGENUM)
3. Briefly discuss the importance of lichens in nature. Briefly discuss the importance of algae in nature.
As the first colonizers on newly exposed rock or soil, lichens are responsible for the chemical weathering of large inorganic particles and the consequent accumulation of soil.
4. Differentiate cellular and plasmodial slime molds. How does each survive adverse environmental conditions?
Cellular slime molds exist as individual amoeboid cells. Plasmodial slime molds are multinucleate masses of protoplasm. Both survive adverse environmental conditions by forming spores.
5. Complete the following table.
Phylum
Method of Motility
One Human Parasite
Archaezoa
(a) Flagella
(b) Giardia
Microspora
(c) None
(d) Nosema
Amoebozoa
(e) Pseudopods
(f) Entamoeba
Apicomplexa
(g) None
(h) Plasmodium
Ciliophora
(i) Cilia
(j) Balantidium
Euglenozoa
(k) Flagella
(l) Trypanosoma
6.
Why is it significant that Trichomonas does not have a cyst stage? Name a protozoan parasite that does have a cyst stage. Trichomonas cannot survive for long outside a host because it does not form a protective cyst. Trichomonas must be transferred from host to host quickly.
7. By what means are helminthes parasites transmitted to humans? Ingestion
8.
Life cycle of the liver fluke Clonorchis sinensis. •
Definitive host
•
Adult
•
Egg
•
Miracidium
•
Intermediate host
•
Cercariae
•
Redia
•
Intermediate host
•
Metacercaria
•
Back to definitive host
9. Most nematodes are dioecious. What does this term mean? To what phylum do nematodes belong? The male reproductive organs are in one individual, and the female reproductive organs in another. Nematodes belong to the Phylum Aschelminthes.
MULTIPLE CHOICES: 1.
How many phyla are represented in the following list of organisms: echinococcus, Cyclospora, Aspergillus, Taenia, Toxoploasma, and Trichinella? 3
2.
Put the above stages in order of development, beginning with the egg. Miracidium Redia Cercaria Metacercaria Adult
3.
If a snail is the first intermediate host of a parasite with these stages, which stage would be found in the snail? Redia
4. Which of the following statements about yeasts are true? Yeast are fungi
Yeasts can form pseudohyphae Yeasts reproduce asexually by budding Yeasts are facultatively anaerobic
5.
Which of the following events follows cell fusion in ascomycetes? Ascospore formation
6.
The definitive host for Plasmodium vivax is. Anopheles
7. Fleas are the intermediate host for Dipylidium caninum tapeworm, and dogs are the definitive host. Which stage of the parasite could be found in the flea? Cysticerus larva
8. These are obligate intracellular parasites that lack mitochondria. Dinoflagellates
9. These are nonmotile parasites with special organelles for penetrating host tissue. Apicomplexa
10. These photosynthetic organisms can cause paralytic shellfish poisoning. Microspora
CHAPTER 13 STUDY QUESTIONS: 1.
Why do we classify viruses as obligatory intracellular parasites? Viruses absolutely require living host cells to multiply.
2.
List the four properties that define a virus. What is a virion? A virus: •
Contains DNA or RNA
•
Has a protein coat surrounding the nucleic acid
•
Multiplies inside a living cell using the synthetic machinery of the cell
•
Causes the synthesis of virions. A virion is a fully developed virus particle that transfers the viral nucleic acid to other cells and initiates multiplication.
3.
Describe the four morphological classes of viruses, then diagram an d give an example of each. Polyhedral, helical, enveloped, complex
4. Draw it label the principal events of attachment, biosynthesis, entry, and maturation of a + stranded RNA virus. Draw in uncoating. PG AN-9
5. Compare biosynthesis of a + stranded RNA and a – stranded RNA virus. Both produce double-stranded RNA with the – strand being the template for more + strands. + Strands act as mRNA in both virus groups.
6. Some antibiotics activate phage genes. MRSA releasing Panton Valentine leukocidin causes a life-threatening disease. Why can this happen following antibiotic treatment. Antibiotic treatment of S. aureus can activate phage genes that encode P-V leukocidin. 7.
Koch’s postulates are used to determine the e tiology of a disease. Why is it difficult to determine the etiology of (A). a viral infection, such as influenza? (B). cancer? (A) Viruses cannot easily be observed in host tissues. Viruses can not easily be cultured in order to be inoculated into a new host. Additionally, viruses are specific for their hosts and cells, making it difficult to substitute a laboratory animal for the third step of Koch’s postulates. (B) Some viruses can infect cells without inducing cancer. Cancer may not develop until long after infection. Cancers do not seem to be contagious.
8.
Persistent viral infections such as (a) Subacute sclerosing panencephalitis might be caused by (b) Common viruses that are (c) latent, in an abnormal tissue.
9.
Plant viruses cannot penetrate intact plant cells because (a) of the rigid cell walls; therefore, they enter cells by (b) vectors such as sap-sucking insects . Plant viruses can be cultured in (c) plant protoplasts and insect cell cultures .
MULTIPLE CHOICES: 1.
biosynthesis of a bacteriophage. Place the following in order for
mRNA DNA polymerase DNA Viral proteins Phage lysozyme 2.
The molecule serving as mRNA can be incorporated in the newly synthesized virus capsids of all of the following except. – strand RNA rhabdoviruses
3.
A virus with RNA dependent RNA polymerase.
Synthesizes double-stranded RNA from an RNA template. 4.
Which of the following would be the first step in the biosynthesis. A complementary strand of DNA must be synthesized from an RNA template.
5.
An example of Lysogeny in animals could be? Latent viral infections
6.
The ability of a virus to infect an organism is regulated by? The host species The type of cells The availability of an attachment site Cell factors necessary for viral replication
7. Which of the following statements is not true? Viruses multiply inside living cells using viral mRNA, tRNA, and ribosomes 8.
Place in order in which they are found in a host cell: Phage nucleic acid Capsid proteins Infective phage particles
9. Which of the following does not initiate DNA synthesis? None of the above pg 398 10. A
viral species is not defined on the basis of the disease symptoms it causes. The b est example of this is. Hepatitis
