Microbiology: MCB 3020 Ch 1 Connect HW Flashcards


Set Details Share
created 1 year ago by c_mylinh
35 views
book cover
Microbiology
Chapter 1
Subjects:
science, biology, microbiology
show moreless
Page to share:
Embed this setcancel
COPY
code changes based on your size selection
Size:
X
Show:

1

Which of the following is true of viruses?
Choose one:

A. They are eukaryotic.

B. They have large genomes.

C. They are not cells.

D. They are prokaryotic.

C. They are not cells.

Viruses are neither prokaryotic nor eukaryotic since they are not cells. Viruses are obligate intracellular parasites and usually have small genomes.

2

A viral genome was one of the first genomes sequenced because
Choose one:

A. viruses cause human diseases.

B. researchers were unable to isolate cellular DNA.

C. viral genomes are relatively small.

D. research money could only be obtained for viral sequencing.

C. viral genomes are relatively small.

While some viruses do cause human diseases, the first virus sequenced was a bacterial virus, φX174. This bacteriophage was chosen due to its small genome size. Special computational strategies needed to be developed to assemble large amounts of sequence data. The genome of Haemophilus influenza was the first DNA sequence completed for a cellular organism.

3

Which marine bacteria are as large as the head of a fruit fly?
Choose one:

A. Vibrio cholera

B. Thiomargarita namibiensis

C. Vibrio fischeri

D. Staphylococcus aureus

B. Thiomargarita namibiensis

The bacterial cells of Thiomargarita namibiensis, a marine sulfur bacterium, are so large that they appear like the head of a fruit fly and can be seen with the naked eye.

4

The collection of sequences sampled from a particular environmental sample is called
Choose one:

A. metagenome.

B. genome.

C. epigenome.

D. transcriptome.

A. metagenome.

Metagenome is the collective term for the mixture of sequences that are obtained when a particular environmental sample is sequenced using various computational strategies.

5

Microbes have shaped human history by
Choose one:

A. being the causative agents of human epidemics.

B. All of these answer choices are correct.

C. being important in the production of certain food products.

D. playing important roles in the geochemical cycling of many elements.

B. All of these answer choices are correct.

Microbes profoundly affect many aspects of human welfare.

6

Early microscopes
Choose one:

A. allowed Robert Hooke to see bacteria.

B. allowed the development of chemotherapy.

C. showed cells in living material.

D. refuted spontaneous generation

C. showed cells in living material.

Robert Hooke’s microscopes were not powerful enough to see bacteria, but did allow him to see cells. Spontaneous generation was refuted by other experimental means, and chemotherapy was developed by physicians working with humans directly.

7

Which scientist contributed to disproving spontaneous generation?
Choose one:

A. Florence Nightingale

B. Robert Koch

C. John Tyndall

D. Edward Jenner

C. John Tyndall

Tyndall, along with Pasteur, helped disprove spontaneous generation. Koch developed a set of postulates for determining whether a particular microbe causes a disease. Nightingale is the founder of medical statistics. Jenner established the practice of immunization, vaccinating people with cowpox to prevent smallpox.

8
card image

The figure below shows Louis Pasteur and his swan-necked flask. This apparatus was used to show that
Choose one:

A. bacteria divide by binary fission.

B. boiling kills microbes.

C. oxygen does not allow spontaneous generation.

D. living things cannot arise in sealed containers.

C. oxygen does not allow spontaneous generation.

Redi showed sealed containers prevented maggots from arising in meat and Spallanzani showed that sealed broth that had been boiled also did not spoil, but both experiments were criticized for excluding oxygen. Pasteur’s swan-necked flask is explicitly “open to air,” so more effectively refuted spontaneous generation.

9

The theory that organisms can arise from inanimate matter is called
Choose one:

A. fermentation.

B. spontaneous generation.

C. endosymbiosis.

D. germ theory.

B. spontaneous generation.

Fermentation is a process by which microbes gain energy by converting sugars into alcohol or other organic compounds. Endosymbiosis is a symbiotic relationship between two organisms with one living inside the other. Spontaneous generation is the theory that organisms can arise from inanimate matter, namely, be generated spontaneously without parents. Germ theory states that infectious diseases are caused by organisms.

10

The first person to visualize a microbe was
Choose one:

A. Stanley Miller.

B. Antoine van Leeuwenhoek.

C. Florence Nightingale.

D. Louis Pasteur.

B. Antoine van Leeuwenhoek.

Antoine van Leeuwenhoek was the first person to observe a single-celled microbe. Pasteur did much work in microbiology, but he was not the first to observe a microbe. Nightingale is the founder of medical statistics and Miller performed experiments simulating early earth.

11

Yersinia pestis, the main causative agent of bubonic plague, was transmitted by
Choose one:

A. rat fleas.

B. mosquitoes.

C. the fruit fly.

D. algae.

A. rat fleas.

Rat fleas were the agents of transmission of bubonic plague, which wiped out a third of the European population in the fourteenth century.

12

Pure cultures
Choose one:

A. are isolated microbial species taken from samples that often contain multiple species.

B. must be used to develop vaccines.

C. can only be obtained through serial dilution of samples.

D. can be obtained for any microbial species.

A. are isolated microbial species taken from samples that often contain multiple species.

A. are isolated microbial species taken from samples that often contain multiple species.

13

Which one of the following is NOT one of Koch’s postulates?
Choose one:

A. When the microbe is introduced into a healthy, susceptible host, the same disease occurs.

B. The microbe is found in all cases of disease, but is absent in healthy individuals.

C. The microbe becomes more virulent with each successive host.

D. The microbe is isolated from the diseased host and grown in pure culture.

C. The microbe becomes more virulent with each successive host.

Koch’s fourth postulate states that the same strain of microbe is obtained from the newly diseased host.

14

Which of the following would allow a disease-causing microbe NOT to adhere to Koch’s postulates?
Choose one:

A. The microbe can infect multiple different species, such as with the rabies virus.

B. The microbe can be grown in pure culture.

C. The microbe is found in all patients with a particular disease but also some patients without symptoms.

D. The microbe is a eukaryotic pathogen.

C. The microbe is found in all patients with a particular disease but also some patients without symptoms.

Koch’s first postulate states that the microbe is found in all cases of disease, but is absent in healthy individuals. Tuberculosis bacteria, for example, are now known to cause symptoms in only 10% of the people infected.

15

The person who introduced vaccination into Europe was
Choose one:

A. Louis Pasteur.

B. Robert Koch.

C. Mary Montagu.

D. Edward Jenner.

C. Mary Montagu.

Prior to 1717, Montagu observed women in Turkey purposely infecting children with aged smallpox material. This permitted a mild form of the disease to develop, which protected against future smallpox infections. Montagu introduced this practice in Europe. The name of the first person to practice this form of immunization is probably lost to history. Both Pasteur and Jenner made contributions to immunization, but these occurred at a later date.

16

Antibiotics are
Choose one:

A. used to treat viruses exclusively.

B. usually human made.

C. effective against all pathogens.

D. sometimes overprescribed.

D. sometimes overprescribed.

Most antibiotics are obtained from bacteria and fungi. Unfortunately, widespread and often indiscriminate use of antibiotics has selected for pathogens that are antibiotic resistant.

17

Which of the following is a difference between antiseptics and antibiotics?
Choose one:

A. Antiseptics kill microbial cells but antibiotics do not.

B. Antiseptics can be taken internally but antibiotics cannot.

C. Antibiotics kill microbial cells but antiseptics do not.

D. Antibiotics can be taken internally but antiseptics cannot.

D. Antibiotics can be taken internally but antiseptics cannot.

Both antiseptics and antibiotics can kill microbial cells. However, antiseptics cannot be taken internally as they are harmful to patients. Antiseptics are used externally on skin, and also on inanimate objects.

18

In 1899, Beijerinck found that the infectious agent of tobacco mosaic disease went through a filter of 0.1μm pore size. Stanley later purified and crystallized the infectious agent from infected tobacco leaves. The infectious agent was found to be a(n)
Choose one:

A. archea.

B. bacterium.

C. protist.

D. virus.

D. virus.

Cells are usually larger than 0.1 μm and would not pass through this filter. Cells cannot be crystallized, but inert viral particles can. Virus are 0.2-0.9 μm.

19

Penicillin is
Choose one:

A. synthesized by Staphylococcus bacteria.

B. a human-designed antibiotic, synthesized to specifically target human pathogens.

C. naturally produced by human cells when they are infected with a bacterial pathogen.

D. produced by a mold and was discovered accidentally.

D. produced by a mold and was discovered accidentally.

Fleming serendipitously discovered that the mold Penicillium notatum could kill Staphylococcus bacteria.

20

Agar is extracted from
Choose one:

A. red algae.

B. blue algae.

C. brown algae.

D. diatoms.

A. red algae.

Agar, which is responsible for making a liquid medium solidify, is extracted from red algae (seaweed).

21

Sergei Winogradsky
Choose one:

A. discovered chemolithotrophs in natural environments.

B. developed a pure culturing system using agar.

C. identified microbes using biotechnology.

D. discovered microbial fermentation.

A. discovered chemolithotrophs in natural environments.

Winogradsky developed the Winogradsky column, which includes environments allowing chemolithotrophy as it mimics a natural wetland.

22

Chemolithotrophs
Choose one:

A. can survive in pure culture using agar.

B. can be isolated using a Winogradsky column.

C. require an organic carbon source.

D. only grow in inorganic solutions rather than organic media.

D. only grow in inorganic solutions rather than organic media.

Chemolithotrophy is defined as a nutritional classification where only inorganic minerals are metabolized. Winogradksy columns are not pure cultures, and agar does not provide the necessary resources for these organisms.

23

The reduction of N2 gas into ammonia is known as
Choose one:

A. fermentation.

B. nitrogen fixation.

C. photosynthesis.

D. nitrification.

B. nitrogen fixation.

The conversion of atmospheric N2 gas into reduced ammonia is known as nitrogen fixation.

24

Endosymbionts in plants
Choose one:

A. regulate the immune system.

B. fix carbon during photosynthesis.

C. fix nitrogen needed for proteins and nucleic acids.

D. break down complex fibers.

C. fix nitrogen needed for proteins and nucleic acids.

Plants fix their own carbon, but as most plants do not consume organic material they do not have sufficient nitrogen without symbiotic relationships with nitrogen fixers. They produce their own fibers for their body, and while they have a form of immune system, it is very different from the animal forms that the gut microbiome of animals regulates.

25

The “rock-eating” bacteria are typically known as
Choose one:

A. chemotrophs.

B. autotrophs.

C. organotrophs.

D. lithotrophs.

D. lithotrophs.

Lithotrophs are also called “rock-eating” bacteria, as they take part in leaching of minerals like copper, zinc, and other metals from the ores.

26

Which of the following is NOT a reason microbes can be difficult to classify?
Choose one:

A. They can exchange genes in non-sexual ways.

B. Their DNA is easily acquired, amplified, and compared using modern techniques.

C. As asexual organisms, the species concept does not apply to them.

D. They are difficult to distinguish using microscopy or culture.

B. Their DNA is easily acquired, amplified, and compared using modern techniques.

Using traditional taxonomy based on morphology and interbreeding, microbes cannot be readily classified to species. However DNA technology can readily sort them based on sequence similarity.

27

Carl Woese proposed the domain classification
Choose one:

A. to replace kingdoms.

B. to divide the single-celled organisms from the multicellular organisms.

C. using shape to classify microbial species

D. to account for two major and distinct prokaryotic groups in addition to eukaryotes.

D. to account for two major and distinct prokaryotic groups in addition to eukaryotes.

While the domain system now is superimposed on kingdoms, these still exist at least for multicellular life. Shape was initially used to classify microbes, but was impractical because of the sheer diversity and was limited by microscope resolution.

28

What is the name of the gene that was used as a “molecular clock” to classify archaea?
Choose one:

A. 16S rRNA

B. 12S rRNA

C. 70S rRNA

D. 80S rRNA

A. 16S rRNA

16S RNA is one of the components of the 30S small subunit of prokaryotic ribosomes. Because of its universality in the genome of prokaryotes, it is commonly used for phylogenetic tree construction.

29

Archaeans
Choose one:

A. are the likely source of chloroplasts and mitochondria.

B. are much more restricted in environment than organisms classified as either bacteria or eukarya.

C. are prokaryotic like bacteria, but their gene expression machinery is more similar to eukaryotic organisms.

D. look like pre-eukaryotic cells with a nucleus.

C. are prokaryotic like bacteria, but their gene expression machinery is more similar to eukaryotic organisms.

Archaeans do not have a nucleus, and tend to have a broad range of environments they can be found in, but DNA comparisons show similarities to eukaryotes, such as in gene expression machinery.

30

The discovery of which cycle is regarded as one of the major milestones in understanding cellular metabolism?
Choose one:

A. Anaerobic respiration

B. Urea cycle

C. Krebs cycle

D. Glycolysis cycle

C. Krebs cycle

German biochemist Hans Krebs discovered the Krebs cycle, or TCA cycle, and this was the first major discovery to elucidate how the products of sugar digestion are converted to carbon dioxide.