Biology quizzes

If your microscope has a resolving power of 0.25 microns, you CAN clearly see structures that are ______ microns apart. (Select all that apply)

0.25, 2.5

If a bacterial cell is roughly 1 micron (micrometer) in length, how many bacteria would cover a distance of 1 meter? (about the length of a baseball bat)

1,000,000

You put 1 mL of a contaminated water sample into 99 mLs of broth to make a 1/100 dilution, and then you plated 0.25 mLs of this dilution on nutrient agar media. After incubation you counted 87 colonies. How many CFU/mL of bacteria were in the original water sample?

3.48 x 104

If you have 10 bacteria on your sandwich and their doubling time is 15 minutes, how many bacteria will be on your sandwich if you leave it out for 4 hours while you are in class?

655,360

You have a mixture of bacteria that each have the following growth requirements: Organism "A" grows in 5-10% NaCl, at 25-30°C Organism "B" grows in 3-6% NaCl, at 22-28°C Organism "C" grows in 5-8% NaCl, at 32-38°C If you want to select for the growth of ONLY Organism "C" what media and incubation temperature should you use?

8% NaCl, 35 degrees Celsius

Multicellular microbes containing nuclei and chloroplasts will get their energy from _______

Algae get their energy from carrying out photosynthesis, in which they turn carbon dioxide from the air + energy from sunlight into oxygen and sugars. Harvesting sunlight through photosynthesis

Which macromolecules contain carbon? (select all that apply) a. Proteins b. Nucleic acids c. Lipids d. Carbohydrates

All

Which of the following are products of the Krebs cycle (select all that apply) Select one or more: a. FADH2 b. NADH c. ATP d. carbon dioxide

All

Which of these are fermentation products of microbes? (select all that apply) Select one or more: a. chocolate b. beer c. cheese d. yogurt e. wine

All

Which of the following structures is not essential for protozoa?

Flagella

Which of the following statements is TRUE regarding the location of these metabolic pathways? Select one: a. The Krebs cycle takes place in the cytoplasm of your cells b. In bacterial cells, glycolysis and the Krebs cycle occur in the same place c. Glycolysis takes place in the mitochondrial matrix d. The electron transport chain is found in the cell membrane of yeast cells e. The electron transport chain is found in the mitochondrial inner membrane of bacterial cells

B

Drugs that disrupt 70S ribosome function will be most useful in treating an infection caused by....

Bacteria

If you FORGOT to do the acetone step of the Gram stain (but did everything else correctly), what would happen?

Both Gram positive and Gram negative cells would stain purple

If grape variety "A" contains the most sugar, grape variety "B" contains a medium amount of sugar and grape variety "C" contains the least amount of sugar, which of the following statements is TRUE? a. Wine made from grape variety "A" will have the lowest amount of alcohol b. Wine made from grape variety "C" will have the lowest amount of alcohol c. All three varieties of grapes will produce wine with the SAME amount of alcohol d. Wine made from grape variety "B" will have the lowest amount of alcohol

C

Which of the following structures would provide a selective advantage for bacteria that are continuously exposed to white blood cells?

Capsule

Which of these structures would enable a bacterium to escape the host's immune system?

Capsule

Which organelle is NOT found in either protozoa or fungi?

Chloroplasts

You are caring for a patient who has been recently diagnosed with an infection caused by the fungus Cryptococcus neoformans. Based on your knowledge, which one of the following patients under your care is MOST at risk for developing a chronic fungal infection if exposed to C. neoformans?

Immunocompromised patients are more at risk for fungal infections. Transplant patients are treated with immunosuppressive drugs to prevent rejection and are at high risk for contracting fungal infections. a 45 year old female undergoing a heart transplant

In the lysogenic cycle of viral replication, the host cell's chromosome gets broken down

In the lysogenic cycle, the viral DNA gets incorporated into the host cell's chromosome and the virus remains dormant

Ribosomal RNA (rRNA) is a good "evolutionary time clock" because

It changes very slowly over time, All organisms have ribosomal RNA, DNA sequences of the ribosomal RNA genes can be compared between organisms, Organisms that are closely related have similar ribosomal RNA

Why is the formation of pseudohyphae dangerous in a clinical setting? (select all that apply)

It enables the yeast to burrow into tissues and spread invasively, It is more resistant to drug treatment than single budding yeast

Some specific ways in which bacteria "resist" antibiotics

Cut up the antibiotic (example: enzymes that chop up the drug) •Spit out the antibiotic (example: efflux pumps that eject the drug) •Alter surface receptors (example: changes to proteins on the bacterial surface prevent the antibiotic from getting in...since antibiotics often use mechanisms that the cell uses to bring other materials like nutrients)

Microbiologist contribution

Developed a method to show that a specific microbe causes a disease → Koch, Showed that microbes come from other microbes, not from non-living materials → Pasteur, Developed a method used even today to get rid of microbes in food and drink → Pasteur, First person to actually view microorganisms using a simple single-lens microscope → Van Leeuvenhoek, Showed that handwashing between patients prevents transmission of pathogens → Semmelweiss

If glucose needs to be transported across a membrane from an area where there is very little glucose to an area with a high concentration of glucose, this would require.....

Energy input

During which phase of the bacterial growth curve are antibiotics MOST effective at targeting bacteria?

Exponential (log)

A noncompetitive inhibitor binds to the active site of an enzyme

F

In the lysogenic cycle of viral replication, the host cell's chromosome gets broken down

F

Average handwashing compliance in U.S. hospitals is around 70%.

False(40%)

True : H. pylori is disappearing from Westernized populations compared to earlier generations, H. pylori can survive in stomach acid, The lack of H. pylori can cause esophageal cancer and acid reflux disease, Barry Marshall drank a flask of H. pylori and gave himself an ulcer

False:H. pylori lives on the skin There is no evidence that H. pylori causes ulcers e. H. pylori is only present in newborns f. H. pylori has only recently been found in human populations

What was the purpose of the "swan neck" bend in the flask that Pasteur used in his experiment?

It trapped microbes from the air so they couldn't get into the broth

Prevent resistance

Keep up to date on immunizations •Avoid unnecessary IV's and catheters •Get cultures of pathogens and treat with the lowest dose of the best antimicrobial agent (ask if an antibiotic sensitivity test has been done) •Complete full course of antibiotic treatment •Use the best/most specific treatment (avoid broad-spectrum antibiotics if possible)...don't ever share antibiotics •Stop antimicrobial treatment when unnecessary •Break the chain of transmission....proper hand hygiene! •Avoid meat from animals that have been treated with antibiotics

An RN in the intensive care unit is caring for a 25-year-old patient with acute respiratory distress syndrome and multisystem organ failure. The patient is requiring mechanical ventilation with high settings to maximize oxygenation. The RN has multiple noninvasive monitors to evaluate organ oxygen saturation and draws labs every 2 hours to monitor the patient's status. The medical team closely follows the patient's lactate (lactic acid) level, which is significantly elevated from the normal value. Which of the following statements best describes why this patient is exhibiting a high serum lactate?

Lactate (lactic acid) is a byproduct of fermentation, allowing an alternative source of energy in the presence of hypoxia (lack of oxygen)

A white blood cell engulfs a pathogen, but instead of getting destroyed, the pathogen remains in the cytoplasm of the white blood cell and continues to multiply. This is most likely due to a defect in which eukaryotic organelle?

Lysosome

Viruses do NOT contain ribosomes. Based on this, which of the domains do you think viruses fall into?

No domain since they don't have ribosomal RNA

Which statement is FALSE? a. Swine flu (H1N1) was a result of antigenic shift b. Once you get a flu shot you don't need to get another one for a long time because your immunity lasts for ten years c. Stomach "flu" (gastroenteritis) only lasts a day or two d. Stomach "flu" (gastroenteritis) may be caused by viruses, bacteria or protozoa

Once you get a flu shot you don't need to get another one for a long time because your immunity lasts for ten years

The enzyme catalase breaks down hydrogen peroxide into water and __________.

Oxygen

Put the general steps of viral replication in order from 1 to 5

Penetration → 2, Release → 5, Adsorption → 1, Assembly → 4, Synthesis → 3

Paralytic shellfish poisoning is a result of...

People eating fish that have consumed toxic algae

Why has it been historically so difficult to develop an effective malaria vaccine?

Plasmodium has different parts of its life cycle in the mosquito gut, mosquito salivary glands, human liver and human red blood cells

If you just wanted to observe what cell shape a particular bacteria is, you could do a ____stain

Simple

If you use a microscope with visible light (wavelength = 0.5 microns) and an objective lens with a numerical aperature (N.A.) of 0.65, which of these structures can you resolve (see clearly as separate) with this microscope? Resolving power = 0.61 (wavelength) / (N.A.) Structures that are _______ apart.

You have correctly selected 1. 0.61 (wavelength) / NA = Resolving distance so the RP of your microscope is 0.469 microns You can clearly see objects that are greater than or equal to this distance apart The correct answers are: 0.5 microns, 4 microns

Which of these represent the steps of viral replication in the correct order?

adsorption, penetration, synthesis, assembly, release

H. pylori is considered an "endangered species" and its decline in Western populations has led to......

an increase in acid-reflux disease

If a bacterium contains a thick layer of peptidoglycan, then it will NOT have..... (select all that apply

an outer membrane, porins

Why do you need a new flu shot each year?

antigenic drift

Many foods are naturally preserved with high salt content (like beef jerky for example). This creates a hypertonic environment. What happens to any bacteria that might contaminate these types of foods?

bacteria lose water, shrink and die

Which of the following would you expect to decompose the FASTEST? a. banana in sealed bag with soil b. banana in unsealed bag without soil c. banana in unsealed bag with soil d. banana in sealed bag without soil

banana in unsealed bag without soil, banana in unsealed bag with soil

Which of the following would you expect to decompose the FASTEST? a. This choice was deleted after the attempt was started. b. banana in unsealed bag without soil c. banana in sealed bag without soil d. banana in unsealed bag with soil e. banana in sealed bag with soil

banana in unsealed bag without soil, banana in unsealed bag with soil

The smooth ER is responsible for (select all that apply)

calcium storage, lipid synthesis

A 0.9% saline solution is considered ISOTONIC. If a patient with a traumatic brain injury is given a 3% saline solution IV, what will happen to his cells?

cells will shrink, losing water

Which eukaryotic organelles are prokaryotic in ORIGIN? (Select all that apply)

cholorplasts, mitochondria

Which of the following can be used to describe/evaluate colony characteristics? Select all that apply

color, size, margin (edge), texture

If magnification is optimized, what else needs to be considered to obtain the best possible image of a specimen?

contrast, resolution

Which of these represents the steps of the Gram stain in the correct order? (Assume that the sample has already been heat-fixed!)

crystal violet--iodine--alcohol--safranin

To diagnose tuberculosis, an acid-fast stain is used. This stain encompasses the following steps: First, a red dye is used to stain all cells. Next, an acid-alcohol rinse is applied to remove the dye from non acid-fast cells. Finally, a blue dye is applied to re-stain the non-acid-fast cells. This procedure represents an example of a _______stain.

differential

An ideal anti-viral drug would be one that _______.

disrupted an essential viral process while causing minimal damage to host cells

Which of the following can have a positive impact on the balance and diversity of your microbiome? (select all that apply)

eating a plant-based diet, having pets in your home, eating a diet rich in fermented foods, spending a lot of time outdoors digging in your garden

Which of the following are techniques used for cultivating animal viruses in the laboratory?

embryonated eggs, tissue culture cells

Which bacterial structure does NOT function in ATTACHMENT?

endospore

The best treatment for a cholera patient is....

oral rehydration therapy

If an organism needs to move water across a membrane it will need to use ____________.

osmosis is the diffusion of water across a semipermeable membrane

Which methods of crossing the plasma membrane do NOT require energy (ATP)?

osmosis, passive diffusion

If you have a patient who complains of lower abdominal pain and frequent urges to empty his bladder, the most likely specimen you will collect for clinical lab testing is ____________. After collecting this sample, you will perform which of the "5 I's" FIRST? ____________.

urine sample; inoculation

Common Misconceptions About Antibiotic Resistance

"Antibiotics make bacteria resistant" •"People become immune/build resistance to antibiotics" •"Only people who use antibiotics regularly are at risk of developing antibiotic-resistant infections" •"Bacteria mutate in order to survive antibiotics"

What is the sequence of RNA that results from transcription of this segment of DNA?5' AAA TAC GGA TTC 3' (coding strand)

AAA UAC GGA UUC

Where does the largest amount of each of these products get formed? ATP Answer 1Choose...Krebs cycleGlycolysisElectron transport chain Precursor metabolites Answer 2Choose...Krebs cycleGlycolysisElectron transport chain Reduced carrier molecules (NADH, FADH2) Answer 3Choose...Krebs cycleGlycolysisElectron transport chain

ATP → Electron transport chain, Precursor metabolites → Glycolysis, Reduced carrier molecules (NADH, FADH2) → Krebs cycle

Which domain contains organisms that may be found in hot springs and glaciers?

Archaea

Which of the following statements best describes why a rising serum lactate (lactic acid) level may be of concern for a patient? Select one: a. Fermentation produces toxic byproducts that cells cannot break down b. Fermentation provides a very limited supply of energy for cells c. Fermentation is harmful for cells d. Fermentation depletes cells of energy

B

Fungal spores differ from bacterial endospores because

Fungal spores are used for reproduction and bacterial endospores are used for survival

If a drug is targeted against chitin, it is most likely to affect

Fungi

Which experimental design would test the hypothesis that "Excess stomach acid cause ulcers"?

Give half the participants antacids and half the participants a sugar pill then measure the number of ulcers per person

Where might the hydrogens (H) from a glucose molecule ultimately end up at the end of ANAEROBIC cellular respiration performed by bacteria? Select one: a. H2O2 (hydrogen peroxide) b. H2O c. FADH2 d. H2S (hydrogen sulfide) e. NADH

H2S (hydrogen sulfide)

If you forgot to do the heat-fixing step prior to the Gram stain, predict what you would see:

Heat fixing is required to attach the cells to the slide prior to staining. If you forgot, the cells would wash off during the staining procedure. You would not see anything on your slide

If the membrane where the electron transport chain is located is NOT selectively permeable, ATP can still be made using the ATP synthase enzyme. Select one: True False

If the membrane is not selectively permeable, then the H+ can diffuse back across the membrane without having to travel through the ATP synthase, and without H+ moving through it, the ATP synthase enzyme is shut off so no ATP will be made. The correct answer is 'False'.

If you wanted to design a drug that would disable protozoan flagella, what would be a good structure to target? (Hint: which structure is only found in eukaryotic flagella?)

Microtubules

Which statements support the theory of endosymbiosis? (select all that apply)

Mitochondria and bacteria both have similar types of ribosomes, Mitochondria have their own circular DNA which is similar to bacterial DNA

Which kingdom category contains organisms that belong to 2 of the 3 domains (new system of classification)?

Monera consist of both bacteria and archaea which are now considered to each be a separate domain since they are actually VERY different at a molecular level!

In many cultures, people use lemon juice as a natural food preservative. If you wanted to test the hypothesis "Lemon juice kills bacteria in food", what would be the best experimental setup?

Prepare one food item and add lemon juice to it and also prepare the same food item without adding lemon juice. After incubating both dishes at the same temperature, inoculate a sample of each food onto an agar plate, incubate and count the number of colonies on each.

If a red blood cell is represented by the size of a cell phone (about 14-15 cm in length), which of these objects would be a good representation of the size of an average bacterial cell?

Remember that a bacterial cell is about one-tenth the size of a red blood cell. The correct answer is: headphone earbud (1.5 cm)

Which is the correct order for the synthesis and transport of a secreted protein?

Rough ER---Golgi---secretory vesicle---plasma membrane

Contact: can be direct or indirect via fomites Vehicle: air, water, food Vector: insect bites

SPREAD OF INFECTION REQUIRES: •RESERVOIR (source of pathogen) •TRANSMISSION Contact: can be direct or indirect via fomites Vehicle: air, water, food Vector: insect bites •INVASION OF HOST •PATHOGENESIS

If you have taken a sample from a patient with a suspected yeast infection, which media would you use to culture the yeast while inhibiting bacterial growth?

Sabouraud's agar is selective for fungi and inhibits the growth of most bacteria due to its pH

What general type of staining technique would be used to highlight bacterial flagella?

Special stain

During which phase of the bacterial growth curve are there both live and dead cells? (Select all that apply)

Stationary, Death

Weakened or attenuated viruses are often used to make vaccines to prevent viral diseases

True

DNA replication in bacteria occurs prior to cell division b. DNA polymerase can only synthesize a 5'-3' strand of DNA

T

A microbiologist inoculates Streptococcus pyogenes and Salmonella enterica into a culture medium. Following incubation, only the Salmonella grows in the culture. What is the most likely explanation?

The culture medium must be selective

Organisms A, B, and C all live in the same habitat where both glucose and lactose sugars are plentiful. Over a period of time, the glucose reserves disappear and only lactose remains as a food source. A: can digest lactose and glucose equally well B: preferentially digests glucose and is not as efficient at extracting energy from lactose, but can partially digest it C: can digest glucose and fructose equally well but cannot digest lactose Which statement expresses what is likely to be observed in this habitat two months after the glucose has disappeared?

The population is made up of mostly organism A and a smaller population of organism B

You have a patient with Valley Fever. You have the following information about different drugs available to you to prescribe for treatment: Cycloheximide disrupts 80S ribosomes Kanamycin disrupts 70S ribosomes Trimethoprim disrupts bacterial folic acid synthesis Itraconazole disrupts ergosterol in fungal cell membranes Metronidazole disrupts DNA replication in anaerobic bacteria and protozoa What should you prescribe him?

Valley fever is caused by a fungal pathogen so this drug is the best choice;itraconazole

All viruses contain DNA as their genetic material

Viruses can have EITHER DNA or RNA as their genetic material

Enzymes

They can be destroyed by heat b. The active site on an enzyme is where a chemical reaction occurs c. They are proteins e. They interact with a specific substrate

Which of these is arranged correctly from smallest to largest?

flu virus---E. coli---yeast

You have a pond water sample containing a "mystery microbe". You observe it and notice that it has a nucleus and other organelles and it is VERY motile. Which organisms can you ELIMINATE? (Select all)

fungi, bacteria

Which of these may result from not having a diverse gut microbiome? (select all that apply)

obesity, allergies, asthma, autoimmune disorders

Bacillus species that could no longer make endospores would be expected to.....

grow well in nutrient-rich soil

Which of the following can impact the balance of a person's microbiome?

having a pet, overconsumption of antibiotics, how you were born, whether or not you were fed formula or breast milk

A triage nurse in the ER begins the assessment of a patient with traumatic brain injury. In this condition, there is cerebral edema (swelling of tissues in the brain), so the administration of a ___________I.V. solution helps to move water out of the cranial space and reduce swelling.

hypertonic

Which of the following functions are carried out by the SMOOTH ENDOPLASMIC RETICULUM?

lipid synthesis, alcohol detoxification

Eukaryotic flagella contain.....

microtubules

DAMPs and PAMPs both induce a similar response from our immune system during trauma or infection is because ____ are structurally very similar to ____.

mitochondria; bacteria

If you looked in a microscope and observed a multicellular organism with hyphae, you could conclude that it is some type of

mold

If cell had defects in its Golgi complex, you would expect to see....

proteins not being delivered to the correct location

Under the microscope, you observe unicellular organisms that contain nuclei but do not contain a cell wall. They are most likely

protozoa

Thinking about how we classify living organisms into domains, which pairs of organisms are most closely related?

protozoa & algae

You are working in a hospital and have just encountered the first victims of an unknown outbreak. Symptoms include fever, cough, chest pain, and trouble breathing. In order to isolate the organism causing the disease, what sample should you use as your inoculum?

respiratory secretions

The sequence of _________is used to determine how closely two organisms are related to one another, because this sequence changes very slowly over time.

ribosomal RNA

Which structures are common to ALL organisms belonging to any of the 3 domains: Eukarya, Bacteria, Archaea?

ribosomes, cell membrane

Which of these structures are essential for bacteria? (select all that apply)

ribosomes, circular chromosome, cell membrane, cytoskeleton

In the Case of the Itchy Dog, what was the cause of death (at a cellular level)?

rotenone inhibited the action of the NADH dehydrogenase, so ATP production was shut down

Dr. Semmelweiss' observations of childbed fever in his hospital led to ideas that....

showed that microbes could be transferred to patients through unclean hands and instruments

Which of these is NOT found in Gram negative bacterial cell walls?

teichoic acids

A protozoan that can form a cyst would be well adapted for survival in.....

the acidic pH of the stomach, dry soil lacking water or nutrients

If a cell has defects in its ___________ it will not be able to control the movement of nutrients and wastes into and out of the cell

the cell membrane controls what goes in and out

The host range of a virus depends on

the surface proteins found on the viral envelope

True about viruses

they can only be viewed with an electron microscope b. they can only reproduce within a host cell c. they are responsible for many emerging infectious diseases like SARS, Ebola, COVID-19 d. they contain genetic material surrounded by a protein "coat" e. they are not made up of cells g. they cannot be classified into a domain

Which is NOT a characteristic of viruses?

they contain ribosomes

Which is NOT a characteristic of viruses? Select one: a. they can only be viewed with an electron microscope b. they are responsible for many emerging infectious diseases like SARS, Ebola, COVID-19 c. they contain genetic material surrounded by a protein "coat" d. they can only reproduce within a host cell e. they are not made up of cells f. they contain ribosomes g. they cannot be classified into a domain

they contain ribosomes

Which of the following statements about Archaea are TRUE? (select all that apply)

they do not contain nuclei and organelles, their membranes are not made up of a lipid bilayer, but rather a monolayer

Bacteria that contain LPS in their cell wall will NOT have (select all that apply)

thick layer of peptidoglycan, teichoic acids

In the case of the sick inmates, what behaviors or practices could have prevented the outbreak?

thorough heating of leftover food used in meal preparation

Which surface is likely to support biofilm formation by bacteria?

your teeth pacemaker your shower curtain urinary catheter