Micro Biology week 1

Question 1

What was Leeuwenhoek’s contribution to the science of microbiology?

Answer 1

He was the first to observe live microorganisms through a microscope.

Question 2

How are the bacteria and the archaea different from all the other cellular microbes?

Answer 2

They have no nucleus.

Question 3

A microorganism has the following characteristics: eukaryotic, multicellular, has cell walls, and grows in long filaments. What is its general classification?

Answer 3

fungus

Question 4

You have isolated microorganisms that are green, photosynthetic, have a cell wall, and do NOT possess a nucleus. These organisms are __________.

Answer 4

bacteria

Question 5

Which of the following is NOT an example of a fungus?

1. mushrooms
2. algae
3. molds
4. yeasts

Answer 5

algae

Question 6

Which of the following is a true statement concerning bacteria and archaea?

1. Bacteria reproduce asexually, while archaea reproduce sexually.
2. While some bacteria are pathogenic to humans, no archaea are known to cause human diseases.
3. Bacteria and archaea have identical types of cell walls.
4. Bacteria are found only in extreme environments.

Answer 6

While some bacteria are pathogenic to humans, no archaea are known to cause human diseases.

Question 7

All of the following individuals showed that cleanliness played a role in human disease EXCEPT __________.

1. Lister
2. Jenner
3. Nightingale
4. Semmelweis

Answer 7

Jenner

Question 8

Koch’s work involving anthrax was significant because it was the first time __________.

Answer 8

a bacterium had been proven to cause a disease

Question 9

Whose experiments supported the existence of a “life force”?

Answer 9

Needham

Question 10

Put the following steps of Koch’s postulates in order:
a. The suspected infectious agent must be isolated and grown outside the host.
b. The suspected infectious agent causes the disease when it is introduced to a healthy, experimental host.
c. The suspected infectious agent must be found in every case of the disease.
d. The suspected infectious agent must be found in the diseased experimental host.

Answer 10

c, a, b, d

Question 11

What is the vector for transmission of yellow fever?

Answer 11

Aedes aegypti mosquitoes

Question 12

Why is this disease called “yellow fever”?

Answer 12

Patients have yellow mucous membranes and an elevated temperature.

Question 13

Yellow fever is caused by a(n) _____.

Answer 13

virus

Question 14

What is the best way to prevent the spread of yellow fever?

Answer 14

Drain standing water and sleep under mosquito netting.

Question 14

Who is credited with the discovery of the cause of yellow fever?

Answer 14

Walter Reed

Question 15

Which of the following is NOT a growing area of microbial study?

1. ultraminiature technology
2. communication within biofilms
3. methods of disease
   transmission
4. reducing antimicrobial resistance

Answer 15

methods of disease transmission

Question 16

Which field of microbiology involves the study of microorganisms in their natural habitats?

Answer 16

environmental microbiology

Question 17

Which of the following techniques could be used to produce a yeast capable of making viral proteins?

Answer 17

recombinant DNA technology

Question 18

Which of the following fields of modern microbiology is NOT directly concerned with the genetic characteristics of a cell?

1. bioremediation
2. recombinant DNA technology
3. molecular biology
4. gene therapy

Answer 18

bioremediation

Question 19

What is matter?

Answer 19

anything that takes up space and has mass

Question 20

What is an atom?

Answer 20

the smallest chemical units of matter

Question 21

What is an element?

Answer 21

composed of a single type of atom

Question 22

Which of the following would contain teichoic acids?

Answer 22

a Gram-positive cell wall

Question 23

Which of the following is NOT a basic process of life?

1. responsiveness
2. sexual reproduction
3. growth
4. metabolism

Answer 23

sexual reproduction

Question 24

Answer 24

Question 25

Which of the following is NOT a characteristic of a eukaryotic cell? 1. can undergo transcription and translation simultaneously 2. presence of a nuclear envelope 3. contain chromosomes composed of DNA and histones 4. presence of membrane-bound organelles

Answer 25

can undergo transcription and translation simultaneously

Question 26

Which of the following statements about bacterial flagella is true? Bacteria can only rotate flagella counterclockwise. Flagella work by undulating. Flagella can rotate 360 degrees. Bacteria can only rotate flagella clockwise.

Answer 26

Flagella can rotate 360 degrees.

Question 27

Taxis is another word for stimulus. caused by the undulating motion of a bacterium. another term for bacterial tumbling. movement towards or away from a stimulus.

Answer 27

movement towards or away from a stimulus.

Question 28

Which of the following terms refers to a bacterium moving towards a light source? Negative phototaxis Negative chemotaxis Positive chemotaxis Positive phototaxis

Answer 28

Positive phototaxis

Question 29

As a bacterium approaches a food source, one would expect runs to become more frequent. flagella to rotate clockwise more frequently. flagella to stop spinning. tumbles to become more frequent.

Answer 29

runs to become more frequent.

Question 30

Why are receptors on the cell surface necessary for bacterial movement? The receptors actually spin the flagella. The receptors physically alter shape to steer the bacterium. The receptors sense the stimulus and send signals to the flagella. The bacterium contains receptors that are sensitive to light.

Answer 30

The receptors sense the stimulus and send signals to the flagella.

Question 31

Which of the following scenarios is an example of bacterial motility? A bacterium traveling through the air from a sneeze A bacterium being removed from the skin during hand washing A bacterium moving towards a food source

Answer 31

A bacterium moving towards a food source

Question 32

Axial filaments are found on staphylococci. spirochetes. streptococci. rod-shaped bacilli.

Answer 32

spirochetes.

Question 33

Answer 33

Question 34

A bacterial cell possesses a glycocalyx. Which of the following is FALSE? It will be less likely to dry out. It will be engulfed more quickly by defensive cells of the host. It will be able to attach to surfaces. It will be more pathogenic.

Answer 34

It will be engulfed more quickly by defensive cells of the host.

Question 35

Peptidoglycans are composed of sugars and _____. teichoic acids nucleic acids lipids amino acids

Answer 35

amino acids

Question 36

One chain of alternating NAGs and NAMs is connected to another chain via _____. tetrapeptides enzymes lipids teichoic acids

Answer 36

tetrapeptides

Question 37

One of the main differences between a Gram-positive and a Gram-negative bacterial cell wall is that the peptidoglycan portion of a Gram-positive cell wall is _____ as compared to a Gram-negative cell wall. positively charged thicker more lipid rich composed of a greater percentage of NAGs than NAMs

Answer 37

thicker

Question 38

Within the peptidoglycan layer, the crossbridges that connect the chains of alternating sugar molecules extend between _____. two N-acetylmuramic acid molecules two glucose molecules two N-acetylglucosamine molecules an N-acetylmuramic acid and an N-acetylglucosamine

Answer 38

two N-acetylmuramic acid molecules

Question 39

The peptidoglycan cell wall of bacteria is most analogous to _____. a chain-link fence a sugary candy shell a rain coat an impenetrable brick wall

Answer 39

a chain-link fence

Question 40

What role do the teichoic acids play within the cell wall of Gram-positive bacteria? They serve to stabilize the cell wall and hold it in place. They serve as pores allowing the passage of ions, nutrients, and amino acids into the cell. They act as crossbridges, holding the peptides and sugar molecules together. They serve as adhesins, allowing bacteria to bind to one another.

Answer 40

They serve to stabilize the cell wall and hold it in place.

Question 41

The region between the outer and inner membranes of a Gram-negative bacterial cell is known as the __________, and it is the location of enzymes that assemble peptidoglycan. intramembranous space lipopolysaccharide layer cytoplasm periplasmic space

Answer 41

periplasmic space

Question 42

A patient is infected with Gram-negative bacteria and is experiencing only mild symptoms. When the patient is given an antibiotic causing lysis of the bacterial cells, he suddenly experiences an increase in inflammation and fever, as well as the formation of blood clots. What explanation best describes what happened? The lysis of the cells releases NAG and NAM from the cell wall. The lysis of the cells releases lipid A from the lipopolysaccharide layer. The antibiotic is toxic and is affecting the patient adversely. Any part of the bacterial cell wall released during lysis is seen as foreign and thereby elicits a severe immune response by the body's immune system.

Answer 42

The lysis of the cells releases lipid A from the lipopolysaccharide layer.

Question 43

Which of the following molecules would be blocked by a cell membrane? Simple alcohols Water Ions Dissolved oxygen

Answer 43

Ions

Question 44

Hydrophobic molecules move across a membrane by passive transport directly across the membrane. through integral transport proteins. by active transport directly across the membrane.

Answer 44

by passive transport directly across the membrane.

Question 45

What is a hallmark of passive transport across cell membranes? It may involve the use of transport proteins. It occurs along an electrochemical gradient, and may involve the use of transport proteins. It requires the use of ATP. It occurs along an electrochemical gradient. It cannot occur without assistance from an integral membrane protein.

Answer 45

It occurs along an electrochemical gradient, and may involve the use of transport proteins.

Question 46

A positively charged sodium ion would require the use of integral protein channels to pass through a cell membrane. freely diffuses directly across the cell membrane. would get stuck in the hydrophobic core of the membrane.

Answer 46

would require the use of integral protein channels to pass through a cell membrane.

Question 47

Which of the following statements regarding active transport is false? It powers the diffusion of water across the cell membrane. It requires the use of a transport protein. It requires ATP.

Answer 47

It powers the diffusion of water across the cell membrane.

Question 48

Which of the following would NOT be found in the cytoplasm of a bacterial cell? nucleoid ribosomes porins endospores

Answer 48

porins

Question 49

Which of the following would NOT be expected to be present in a biochemical analysis of an archaeal cell? peptidoglycan membrane proteins membrane lipids ribosomes

Answer 49

peptidoglycan

Question 50

In a hypotonic environment, the volume of a plant cell enlarges as the cytoplasm pushes against the cell wall. Which organelles are most likely able to store that extra water? vacuoles vesicles peroxisomes mitochondria

Answer 50

vacuoles

Question 51

How are the bacteria and the archaea different from all the other cellular microbes? They have cell walls. They have no nucleus. They reproduce asexually. They can move.

Answer 51

They have no nucleus.

Question 52

Microbiologists study parasitic worms because __________. they were not studied by early microbiologists they usually contain bacteria and other microbes they are microscopic as adults they cause diseases that are diagnosed by finding microscopic eggs in clinical specimens

Answer 52

they cause diseases that are diagnosed by finding microscopic eggs in clinical specimens

Question 53

Answer 53

Question 54

Spallanzani's experiments concerning spontaneous generation were NOT universally accepted because __________. he did not give proper credit to Needham for his experiments he did not know which bacteria were growing in his flasks he eliminated air from his flasks by sealing them he did not heat his infusion flasks long enough

Answer 54

he eliminated air from his flasks by sealing them

Question 55

Put the following steps of Koch's postulates in order: a. The suspected infectious agent must be isolated and grown outside the host. b. The suspected infectious agent causes the disease when it is introduced to a healthy, experimental host. c. The suspected infectious agent must be found in every case of the disease. d. The suspected infectious agent must be found in the diseased experimental host. c, b, a, d c, a, b, d d, b, c, a a, d, c, b

Answer 55

c, a, b, d

Question 56

Which of the following techniques could be used to produce a yeast capable of making viral proteins? recombinant DNA technology bioremediation genome sequencing gene therapy

Answer 56

recombinant DNA technology

Question 57

Which of the following refers to the use of bacteria or other microbes to detoxify pollutants? recombinant DNA technology bioremediation biochemistry biotechnology

Answer 57

bioremediation