Exam 1 Micro Flashcards

The DNA found in most bacterial cells

a. is circular in structure

b. is surrounded by a nuclear membrane

c. is found in multiple copies

d. is linear in structure

e. utilizes histones for chromosomal packaging

A definitive host harbors which stage of a parasite?

a. miracidium

b. larva

c. cyst

d. adult

An envelope is acquired during which of the following steps?

a. adsorption

b. penetration

c. biosynthesis

d. release

e. uncoating

Which of the following statements about helminths is FALSE?

a. They are multicellular animals

b. Some have male and female reproductive organs in one animal

c. They have eukaryotic cells

d. All are parasites

e. They are heterotrophic

Which of the following is NOT used as a criterion to classify viruses?

a. biochemical tests

b. nucleic acid

c. morphology

d. size

e. number of capsomeres

Which of the following statements is INCORRECT regarding prokaryotic cells?

a. Their DNA is not enclosed within a membrane

b. They typically have a circular chromosome

c. They lack a plasma membrane

d. They reproduce by binary fission

e. They lack membrane-enclosed organelles

Which of the following statements regarding protozoa is FALSE?

a. Some protozoan pathogens are transmitted by arthropod vectors

b. Protozoa are unicellular eukaryotes

c. Most protozoa reproduce asexually

d. Protozoa are common in water and soil

e. Nearly all protozoa cause disease

Helminths diseases are usually transmitted to humans by

a. vectors

b. genitourinary route

c. aerosols

d. respiratory route

e. gastrointestinal route

Which of the following statements about gram-negative cell walls is FALSE?

a. They protect the cell in a hypotonic environment

b. They are sensitive to penicillin

c. They are toxic to humans

d. They gram reaction is due to the outer membrane

e. They have an extra outer layer composed of lipoproteins, lipopolysaccharides, and phospholipids

Which of the following structures is NOT found in some prokaryotic cells?

a. pilus

b. cilium

c. peritrichous flagella

d. flagellum

e. axial filament

In the malaria parasite life cycle, humans are the ________ host, while mosquitoes are the ________ host as well as the vector.

a. temporary; final

b. definitive; intermediate

c. intermediate; intermediate

d. vector; intermediate

e. intermediate; definitive

Mycobacterium tuberculosis is very difficult to stain because of the

a. location of the DNA within the cell

b. large amounts of a waxlike lipids present in its cell wall

c. lack of a cell wall

d. presence of ribosomes in the cytoplasm

You have isolated a motile, gram-positive cell with no visible nucleus. You can safely assume that the cell

a. has a mitochondrion

b. has a cell wall

c. lives in an extreme environment

d. has cilia

e. has 9 pairs + 2 flagella

A feature that may be found in viruses but never in bacteria is

a. a sensitivity to antibiotics

b. they cannot reproduce themselves outside the host

c. an ability to infect more than one type of host

d. may contain an RNA genome

e. the ability to pass through 0.22 micrometer pore filters

Which of the following statements is TRUE?

a. A cell can produce many endospores

b. A cell produces one endospore and keeps growing

c. Endospores allow a cell to survive environmental changes by producing a dormant period with no growth

d. Endospores are easily stained in a Gram stain

e. Endospores are for reproduction

The terms "run" and "tumble" are generally associated with

a. clustering properties of certain rod-shaped bacteria

b. taxic movements of the cell in response to attractants or repellents

c. cell membrane synthesis

d. cell wall fluidity

Which of the following organelles most closely resembles a prokaryotic cell?

a. vacuole

b. nucleus

c. mitochondrion

d. Golgi complex

e. cell wall

Which structure protects bacteria from being phagocytized?

a. slime layer

b. cell wall

c. cell membrane

d. fimbriae

e. capsule

The characteristic most notable regarding the mycoplasmas is that they

a. produce endospores

b. lack cell walls

c. are nonpathogenic

d. are aerotolerant

e. carry out fermentative metabolism

The theory of spontaneous generation was refuted by the work of

a. Robert Koch

b. Antoni van Leeuwenhoek

c. Louis Pasteur

d. Robert Hooke

Which of the following is NOT one of the 5 I's?

a. introspection

b. inoculation

c. identification

d. isolation

Which of the following is not an example of a differential stain?

a. gram stain

b. endospore stain

c. acid fast stain

d. methylene blue

If a gram stain is not clear, and you are certain is it being performed correctly, which of the following would be the thing to do...

a. capsule stain

b. acid fast stain

c. flagella stain

d. endospore stain

Several bacteria that form spores are important human pathogens. Which one of the following is the most accurate statement about bacterial spores?

a. They are killed by boiling for 10 minutes

b. They are produced primarily by gram-negative cocci

c. They are produced by anaerobes only in the presence of oxygen

d. They are formed when the bacterium is exposed to antibiotics

e. They are metabolically inactive, yet can survive for years in the inactive state

Hemolytic (hemoylsis) properties of bacteria can be best viewed using which of the following.

a. Manitol Salt Agar

b. Salmonella/Shigella Agar

c. MacConkey Agar

d. Blood agar

The acid fast stain is useful in identifying which of the following?

a. flagella

b. endospores

c. viruses

d. mycobacterium

Lowenstein-Jenson agar is used for isolation of what?

a. Staphylococcus

b. Mycobacterium

c. Cornebactrerium

d. Streptococcus

A fastidious organism must be grown on what type of medium?

a. differential medium

b. enriched medium

c. general purpose medium

d. defined medium

Which of the following is found in both Gram-postitive and Gram-negative bacteria?

a. cell wall

b. endotoxin

c. lipopolysaccharide

d. outer lipid membrane

Mycobacterium tuberculosis would appear as what when viewed under a microscope following acid fast staining?

a. blue cocci

b. pink bacilli

c. blue bacilli

d. pink cocci

In general, most DNA viruses multiply in the host cell's _____, while most RNA viruses multiply in the host cell's _____.

a. nucleus; cytoplasm

b. cell membrane, cytoplasm

c. cytoplasm; cell membrane

d. cytoplasm; nucleus

Viruses that cause infection resulting in alternating periods of activity (with symptoms) and inactivity (without symptoms) are called

a. prions

b. latent

c. oncogenic

d. viroids

The organelle whose purpose primary function is to produce proteins is the

a. chloroplast

b. ribosomes

c. nucleus

d. mitochondria

Which organelle do algae contain that protozoa do not?

a. locomotor organelle

b. nucleolus

c. mitochondria

d. chloroplast

Viruses cannot be cultivated in/on

a. live mammals

b. blood agar

c. tissue culture

d. bird embryos

Both flagella and cilia are found primarily in

a. protozoa

b. fungi

c. algae

d. both protozoa and fungi

Which of the following diseases is caused by a retrovirus?

a. cat-scratch fever

b. Lassa fever

c. HIV

d. anthrax

All Protozoa

a. live as a trophozoite

b. can become an endospore

c. use flagella for locomotion

d. can become a cyst

Which ORGANELLES has been proposed to have previously been a bacteria that was endocytosed by another bacteria to become an organelle (Endosymbiotic Theory)?

a. Mitochondria

b. Chloroplast

c. Ribosome

d. Golgi apparatus

True or False: Adult helminths are all microorganisms.

a. True

b. False

The process of dissolving the envelope and capsid to release the viral nucleic acid is

a. uncoating

b. adsorption

c. synthesis

d. penetration

During respiration, glucose is converted into pyruvate through ________, and pyruvate is oxidized into CO2 through ________.

a. glycolysis/fermentation

b. glycolysis/the Krebs Cycle

c. the Krebs Cycle/glycolysis

d. the Krebs Cycle/the glyoxylate cycle

Which of the following is LEAST likely to affect the activity of an enzyme?

a. temperature

b. substrate concentration

c. oxygen concentration

d. pH

Which of the following is NOT an advantage conferred on microbial cells by a biofilm?

a. protection from environmental stresses

b. formation of microenvironments

c. extension of the microbial growth phase

d. ability to stick to a substrate

In which phase of the growth cycle is the antibiotic penicillin most likely to kill bacteria

a. Lag Phase

b. Plateau Phase

c. Exponential Phase

d. Death Phase

Which of the following groups of microbes do NOT use oxygen as their final electron acceptor but can detoxify oxygen enough to live in its presence?

a. obligate anaerobes

b. microaerophiles

c. facultative anaerobes

d. aerotolerant anaerobes

Why do organisms growing by anaerobic respiration generate less ATP than organisms growing by aerobic respiration?

a. They don't use electron transport to generate proton motive force

b. Much less NADH is produced to be used as an electron donor

c. O2 has the most positive reduction potential and thus is a better electron acceptor

d. They don't generate ATP by oxidative phosphorylation

Which elements are required by all cells in the largest amounts?

a. phosphorus, oxygen, sulfur, and carbon

b. nitrogen, sulfur, iron, manganese, and phosphorous

c. carbon, oxygen, hydrogen, sulfur and nitrogen

d. magnesium, hydrogen, nitrogen, and iron

Photoautotrophs use ________ as an energy source and ________ as a carbon source.

a. light/organic molecules

b. organic molecules/CO2

c. light/CO2

d. inorganic molecules/organic molecules

Which characteristic distinguishes growth factors from other micronutrients?

a. They have an organic composition

b. They are essential for growth

c. Cells are unable to biosynthesize them

d. They have only monovalent ions

Which type of macromolecules in Escherichia coli comprise the largest fraction of the microbe's total biomass?

a. DNA and RNA

b. proteins

c. carbohydrates

d. lipids

Some bacteria are obligate anaerobes. Which of the following statements best explains this phenomenon?

a. They can produce energy both by fermentation and by respiration using the Krebs cycle and cytochromes

b. They do not form spores

c. They cannot produce their own ATP

d. They lack superoxide dismutase and catalase

Enzymes catalyze chemical reactions by

a. increasing the activation energy, thus increasing the rate of reaction

b. releasing free energy

c. lowering the activation energy, thus increasing the rate of the reaction

d. making the reaction exergonic