BIOL 1002 CH 20

What is the role of nitrogen-fixing bacteria?

Nitrogen-fixing bacteria capture nitrogen gas from the air and using hydrogen produce ammonium, which can be used as a nitrogen source by plants.

What is the definition of an anaerobic cell?

A cell that does not require oxygen for its energy-producing metabolism and consequently, can survive in an oxygen-free environment

What is the major difference between a virus and a viroid?

Viruses have a protein coat and viroids do not.

You are a doctor treating a patient. Which of the following is most likely to lead you to diagnose Lyme disease?

bullseye rash

What is the size range of bacteria and archaea?

0.2 to 10 micrometers

Why is it that prokaryotic cells evolve more quickly than eukaryotic cells?

Rapid reproduction provides additional opportunity for mutations that are responsible for genetic variability

Which structure helps bacteria to attach within the tissues that they will infect?

Capsule. The gelatinous capsule that covers some bacteria helps them attach to the tissues that they will infect.

From which cell does the sex pilus originate during bacterial conjugation?

The donor cell. The sex pilus originates from the donor cell.

The genetic material of HIV consists of _____.

single-stranded RNA

What is the concern about using antibacterial and antimicrobial soaps?

The use of any chemical that kills bacteria can eventually lead to resistance to that chemical in the population of bacteria.

Your dog is diagnosed with Lyme disease, which your veterinarian treats the same as a person would be treated. Which of the following is she most likely to prescribe?

an antibiotic

In prokaryotes, _______ is the transfer of DNA from one cell to another via temporary connection.

conjugation

Which of the following diseases is caused by the bacterium, Clostridium tetani?

tetanus.

Which of these binds to receptor molecules on the host cell membrane?

Glycoproteins on the viral envelope recognize and bind to receptors on the host cell.

What is the source of a viral envelope?

host cell membrane

Bioremediation is __________.

the breakdown of pollutants by living organisms, particularly bacteria

Some bacteria have an impact on human nutrition. What vitamin does our intestinal bacteria synthesize that we absorb for our use?

vitamin K. This is a fat-soluble vitamin that is important in blood clotting.

Which of the following statements best describes the end result of bacterial conjugation?

One cell has given a copy of a plasmid to another cell and kept one copy for itself.

Why are we constantly warned to make sure that hamburger and other meats are cooked thoroughly?

.to warn people to provide enough heat to kill Escherichia coli O157:H7 contaminating the meat. This bacterium can release a toxin that damages the intestinal tract and other organs.

What is a major role of the Centers for Disease Control and Prevention?

Monitor and report the state of the health of the U.S. citizenry.

A particular antibiotic kills 99% of a bacterial population. What will be the result of the continued application of this antibiotic?

Over time, the antibiotic will become less effective at killing the bacteria.

Life as we know it cannot flourish on the moon but it might be possible for it to survive. What life form on Earth might survive on the moon?

bacterial endospores

Which of the following is considered to be the most effective biological agent used in terrorist attacks?

bacterial endospores of the agent that causes anthrax

are viruses that only infect bacteria.

bacteriophage

What is the major means of reproduction in prokaryotes?

binary fission. Binary fission produces genetically identical copies of the original cell.

Dental plaque is one example of a(n) ________ , a colony of different prokaryote species that secrete slime that sticks the cells to a substrate and to each other.

biofilm

_______ is the use of organisms to remove or detoxify toxic substances in the environment.

bioremediation

What is a possible outcome of conjugation in prokaryotic cells?

new genetic combinations within the species. These recombinants may be able to survive under a greater variety of conditions.

What is a major difference between the domains, Bacteria and Archaea?

peptidoglycan in the cell wall of bacteria but not the archaea. Peptidoglycan is a polysaccharide that strengthens the cell wall of bacteria and is not found in archaea.

In terms of abundance, which of the following is Earth's predominant form of life?

prokaryotes

In the process known as _______ , a single bacterium divides in half, producing two identical offspring.

prokaryotic fission

Double-stranded viral DNA is incorporated into a host cell as a _____.

provirus

Which of the following contributes the LEAST to the problem of antibiotic resistance?

taking the entire course of antibiotics as prescribed by the doctor

Which of these is the viral genome?

HIV is an RNA virus

Which of these is reverse transcriptase?

Inside the protein coat on each of the RNA molecules

The general term for organisms that are capable of producing disease is ____.

pathogens

How is cholera, a disease that is a major killer in poorer parts of the world, spread?

contaminated drinking water

What is an advantage of having a flagellum?

ability to migrate toward nutrients

What is the smallest infectious agent that infects humans and exists and replicates as a single protein?

prion

There are four bacteria in an egg salad that is left out at room temperature. After two hours, how many bacteria will be in the egg salad?

256. The bacteria would double 6 times in 2 hours, so the total number of bacteria in the egg salad would be 256.

In the projected video showing the growth of bacteria, why did the bacteria grow up to the edge of the area with antibiotics, pause, then continue to grow across the area with antibiotics?

A few bacteria experienced random mutations in their DNA, which allowed some of them to grow even though antibiotics were present.

Which of the following correctly describes what the video referred to as a "microbial cure"?

Antibiotics are used to kill all of the infectious bacteria in a person.

Over time, bacteria have become increasingly resistant to antibiotics. Which of the following best explains this in terms of natural selection?

Bacteria that happen to have natural resistance to antibiotics survived and reproduced.

Which of the following is true? Lyme disease is spread by ticks and mosquitoes. Lyme disease is spread by mosquitoes. Lyme disease is spread by ticks. It is unknown as to how Lyme disease is spread.

Lyme disease is spread by ticks.

Some bacteria can produce slime that allows them to aggregate into colonies on surfaces. The result is a biofilm. How could biofilms be responsible for tooth decay?

Biofilms are not removed by brushing, so bacterial growth and activity initiates tooth decay. Within biofilms, bacteria produce acidic metabolic end products that eat away at tooth enamel causing tooth decay. Metabolic activity is increased in biofilms, enhancing tooth decay.

Your aunt takes a canoe trip through the Boundary Waters in Northern Minnesota. She later finds out she contracted Lyme disease while on the trip. Which of following is the most likely cause of her infection?

Borellia burgdorferi

Which of the following describes a viral particle?

DNA or RNA surrounded by a protein coat. They have none of the cellular structures or functions found in cells. Viruses are not cells and do not have a characteristic cellular membrane.

The rapid and inexpensive routine laboratory procedure used to classify the bacterial world into two major groups is called the __________.

Gram stain. This is a staining technique that classifies bacteria as gram-positive or gram-negative.

The polymerase chain reaction requires a heat-resistant enzyme. What is the relationship between this fact and hot springs in Yellowstone National Park?

Heat-resistant enzymes can be extracted from heat-resistant bacteria growing in Yellowstone National Park hot springs.

What is the function of reverse transcriptase?

It catalyzes the formation of DNA from an RNA template.

If the United States is like Europe, which of the following will be true?

It will be discovered that even more species cause Lyme disease.

Which of the following genera contains spherically shaped bacteria?

Micrococcus. The "-coccus" in the name implies a spherical shaped.

Why did life begin on Earth using an anaerobic mode of metabolism?

The atmosphere contained no oxygen at that time.

Why are prokaryotes the most abundant living organisms on Earth?

They are able to adapt to a wide range of habitats. Through mutation, Bacteria and Archaea are able to take advantage of virtually all the environmental habitats found on Earth.

Why do virologists consider viruses to be nonliving?

They are not cells nor are they composed of cells, the basic components of life.

What makes it difficult to distinguish between bacteria and archaea?

They are small and structurally similar.

What is the purpose of prokaryotic flagella?

They provide a mechanism of motility for the cell.

True or false. Bacteria reproduce by an asexual process in which one parent cell gives rise to identical daughter cells.

True. Bacteria reproduce by binary fission, which is an asexual process in which one parent cell splits in two to give rise to identical daughter cells.

True or False. During bacterial conjugation, the recipient cell receives a single-stranded loop of DNA.

True. One strand of the plasmid enters the recipient cell; this strand must be replicated in the recipient cell to produce a double-stranded plasmid that can replicate independently of the bacterial chromosome.

Why is it possible for different microorganisms to extract energy not only from carbohydrates and other biological molecules but from a large variety of substances, such as petroleum, methane, benzene, toluene and even inorganic molecules, such as hydrogen, sulfur, ammonia, and iron?

Where energy sources were available, life adapted to use them through processes of natural selection. Whereas some things are toxic to some life forms, other organisms adapted mechanisms for releasing and capturing energy within them.

Which of the following would initiate sporulation in bacteria?

environmental conditions, such as desiccation, that make the environment inhospitable. These conditions can no longer support the bacterium so it forms endospores to survive.

___ are organisms that can live and grow in the absence of oxygen.

anaerobes

In the video, what does the UK's Chief Medical Officer suggest for promoting the development of new antibiotics?

encouraging big pharmaceutical companies to start investing again in new drug research and development

When some bacteria are exposed to harsh conditions, they produce ______ , thick-coated protective structures that form within the bacterial cell.

endospores