Chapter 1 Humans and the Microbial World

Which defines spontaneous generation? -Life arose from non-living matter. -Organisms continuously evolve. -Life arose from living matter.

-Life arose from non-living matter.

Benefits of normal microbiota include all EXCEPT which of the following? -They compete with pathogens, thereby preventing disease -They aid in digestion by helping degrade foods we otherwise could not digest -They damage host tissue, allowing our immune system to rid the body of microbes

-They damage host tissue, allowing our immune system to rid the body of microbes

A(n) _____ is the term used for any disease-causing microorganism.

pathogen

_______ is credited with disproving spontaneous generation using broth in swan-neck flasks. -Lazzaro Spallanzani -John Needham -Louis Pasteur -Francesco Redi -Robert Koch

-Louis Pasteur

_______ showed that flasks containing various broths gave rise to microorganisms even when the flasks were boiled and sealed with a cork. -Francesco Redi -Lazzaro Spallanzani -John Needham -Louis Pasteur

-John Needham

Why do microorganisms serve as important models for study of higher organisms? -Microorganisms exist in many different varieties so there are a lot to choose from. -Microorganisms have the same fundamental metabolic and genetic properties as other organisms. -Microorganisms produce energy in a simpler manner than more complex organisms. -Microorganisms cause diseases in other organisms that need to be cured.

-Microorganisms have the same fundamental metabolic and genetic properties as other organisms.

Rank the steps in the scientific process in order. Start with the earliest at the top. -Develop an explanation and then devise an experiment to test this explanation. -Collect data from this experiment and draw a conclusion. -Communicate the methods, results, and conclusions. -Make an observation about something and ask a question about the situation.

-Make an observation about something and ask a question about the situation. -Develop an explanation and then devise an experiment to test this explanation. -Collect data from this experiment and draw a conclusion. -Communicate the methods, results, and conclusions.

True or false: We could not survive without microorganisms, but they can also be harmful.

true

True or false: Without microorganisms, we would run out of certain nutrients.

true

Why do microorganisms serve as important models for study of higher organisms? -Microorganisms have the same fundamental metabolic and genetic properties as other organisms. -Microorganisms cause diseases in other organisms that need to be cured. -Microorganisms exist in many different varieties so there are a lot to choose from. -Microorganisms produce energy in a simpler manner than more complex organisms.

-Microorganisms have the same fundamental metabolic and genetic properties as other organisms.

A testable explanation for an observation is called a(n) _____.

hypothesis

Organisms that populate the human body and which protect it from disease are termed normal _____.

microbiota, flora, biota, or microflora

Select all that apply: Microorganisms are useful in the study of higher life forms for which of the following reasons? -Microorganisms have the same fundamental genetic properties. -There are fewer species of microorganisms, so studying them is simpler. -Microorganisms lack cells, making them easier to observe with a microscope. -Microorganisms have the same basic metabolic mechanisms. -Microorganisms multiply quickly. -Microorganisms are cheaper to study.

-Microorganisms have the same fundamental genetic properties. -Microorganisms have the same basic metabolic mechanisms. -Microorganisms multiply quickly. -Microorganisms are cheaper to study.

The principle that microorganisms cause certain diseases is called the _____ Theory of Disease.

Germ

Tyndall and Cohn's experiments in the 1870s showed the presence of a heat-resistant form of bacteria called a(n) _____.

endospore

The concept of living things arising from vital forces in non-living or decomposing materials was known as which of the following? -Germ theory of disease -Biogenesis -Spontaneous generation -Deductive reasoning

-Spontaneous generation

Benefits of normal microbiota include all EXCEPT which of the following? -They compete with pathogens, thereby preventing disease -They damage host tissue, allowing our immune system to rid the body of microbes -They aid in digestion by helping degrade foods we otherwise could not digest

-They damage host tissue, allowing our immune system to rid the body of microbes

Which of the following about microorganisms is true? -They are always harmful. -We could not survive without them. -They have killed far fewer people than have been killed in wars.

-We could not survive without them.

Why were Louis Pasteur's experiments with swan-necked flasks so important in helping disprove the theory of spontaneous generation? -They were effective in killing endospores present in other researchers' experiments, thereby keeping the cultures sterile. -They were made from hay infusions that contained endospores, so even after boiling, broths became cloudy from growth. -They demonstrated the even in a sterile environment, microbes could spontaneously generate from non-life. -They ended arguments that a "vital force" was necessary for spontaneous generation, while preventing contamination from microbes in the air.

-They ended arguments that a "vital force" was necessary for spontaneous generation, while preventing contamination from microbes in the air.

Select all that apply: Which of the following are manufactured by microbial fermentation? -Yogurt -Beer -Ice cream -Fresh milk -Cheese

-Yogurt -Beer -Cheese

Technically speaking, viruses are not microorganisms because they are not ______. -big enough for life -carbon-based -composed of cells

-composed of cells

The work of John Tyndall and Ferdinand Cohn ______. -explained why some spontaneous generation investigators got different results from those of Pasteur -showed that all microbes caused disease if they enter the human body -demonstrated that boiling kills all types of microbes in broths, and thus can ensure sterilization -produced results contradicting Pasteur, and thus demonstrating the idea of spontaneous generation

-explained why some spontaneous generation investigators got different results from those of Pasteur

In general, disease-causing organisms are referred to as which of the following? -pathogens -microorganisms -animalcules -bacteria

-pathogens

Today, the bacteria added to some fermented milk products are advertised as _______. -probiotics -antibiotics -antibodies -prophages

-probiotics

Without microorganisms, substances required for human life such as O2 and organic nitrogen would ______. -run out -be degraded -accumulate

-run out

In 1749, John Needham produced results that _______ spontaneous generation when he showed that broths that had been boiled and then sealed with a cork _______. -refute; remained sterile and did not develop microorganisms -support; could still give rise to microorganisms -support; remained sterile and did not develop microorganisms -refute; could still give rise to microorganisms

-support; could still give rise to microorganisms