Microbiology Exam 1 Study Questions Chapter 1

In Louis Pastuer's experiment, what did the following do? Beef broth: Bunsen Burner: Flask with S-shaped curve: Air:

-The beef broth provided a nutritious environment to support microbial growth -The Bunsen burner provided heat that destroyed microorganisms already present in the beef broth -The flask with S-shaped neck provided the physical conditions for trapping airborne containment and preventing microorganisms from entering the flask -The air provided a source of potential external microbial contaminants Although the design of this experiment may seem very simple, its significance is great because it provided the evidence to disprove the theory of spontaneous generation.

Which of the following represents the correct format for the scientific name of an organism?

1) First name MUST be capitolized, the rest lowercase 2) Second name is all lowercase 3)The WHOLE name must be italizised. Scientific names are composed of the genus name, which is capitalized, and the species name, which is always lowercase. The entire scientific name is always underlined or italicized.

Describe the three main ideas of biogenisis

1) Life can arise as a result of microorganisms present in nonliving matter 2)Living cells can arise ONLY from preexisting living cells 3)Microorganisms present in nonliving matter can lead to new microorganisms [Louis Pasteur and others have conducted experiments that demonstrated the concept of biogenesis, which holds that microorganisms do not originate from mystical forces present in nonliving matter but rather arise from other living microorganisms]

Which of the following conclusions can be drawn from Pasteur's experiment involving the flasks with S-shaped necks?

1) Microbial life can be destroyed by heat 2)Microbes can be blocked from accessing favorable growth environments 3)Microorganisms can be present in nonliving matter,such as air,liquids, and solids 4)Pasteur's observations support the theory of Rudolf Virchow's biogenesis

Given what you have learned from the design of Pasteur's experiment, which of the following would be considered an aseptic technique?

1) Taking steps to prevent contaminants from entering sterile solutions 2)Wearing gloves when handling sterile laboratory equipment 3)Using a Bunsen burner (flame) to heat a wire inoculating loop prior to use

Describe the three main ideas of spontaneous generation.

1. Living cells can arise from nonliving matter under favorable conditions 2.Life can arise spontaneously from nonliving matter 3.Vital forces in nonliving mater can lead to a new life. key words: nonliving,forces (these people believed in demons and karma making bad things happen)

Mycology is the study of A.mycoplasma. B.molds, yeast, and mushrooms. C.molds. D.mushrooms. E. protozoa.

B. molds,yeast, and mushrooms

Which of the following matches the organisms described with the correct domain? A.bacteria--unicellular, eukaryotic organisms with cell walls that do not contain peptidoglycan B.bacteria--unicellular, eukaryotic organisms that always lack cell walls C.eukarya--single-celled and multicellular organisms, with a defined nucleus and a variety of nutritional sources D.archaea--multicellular, eukaryotic organisms that do not have cell walls

C. Eukarya-single-celled and multicellular organisms with a defined nucleus and a variety of nutritional sources Eukarya is the domain that includes only organisms with cells that have a true nucleus. These organisms belong to the nutritionally diverse Kingdoms Protista, Fungi, Plantae, and Animalia.

Consider organisms that are eukaryotic, are found in both unicellular and multicellular forms, may resemble plants but are not photosynthetic, have chitin in their cell walls, and absorb organic nutrients from decomposing material in the environment. These organisms would be classified as which of the following types of organisms?

Fungi. Fungi are eukaryotic organisms that are found in both unicellular forms (yeast) and multicellular forms (molds) and absorb nutrition from decomposing organic material.

Which physician is first associated with vaccination?

Jenner

A disease breaks out among sheep in California. A scientist takes blood from the sheep and grows a previously unknown organism. That organism is then injected into a healthy sheep. The healthy sheep becomes sick with the same symptoms as the original sheep and dies. That sheep's blood is then cultured, and the original organism is isolated. This applies the principles of __________.

Koch's postulates. Koch's postulates rely on very specific factors and steps conducted to prove that a particular organism is the cause of a disease: (1) The causative agent must be isolated in every case of the disease. (2) The causative agent must be cultured outside the host. (3) When injected into a healthy, susceptible host, the host must get the disease. (4) The same etiologic agent must be cultured from the once healthy host when it becomes sick.

The arguments supporting spontaneous generation were finally disproved by

Louis Pasteur Although Rudolf Virchow was the first to create the term "Biogenesis", Pasteur's experiment with the S-shaped flask finally disproved spontaneous generation. Virchow wasn't credited at the time because people were in high believe that karma and curses caused illnesses

Describe the story about spontaneous generation and how biogenesis challenged that theory.

The germ theory states that microorganisms are responsible for causing disease. This theory was initially not widely accepted; instead, many people believed that disease was caused by demons or was punishment for wrongdoing. In addition, up until the second half of the nineteenth century, it was believed that certain forms of life could arise spontaneously from nonliving matter. Life, it was thought, could spontaneously emerge in favorable environments, such as moist soil, manure, and decaying corpses.In 1858, German scientist Rudolf Virchow challenged the theory of spontaneous generation. He argued for the concept of biogenesis, which states that living cells can arise only from preexisting cells. However, he could not offer scientific proof, so arguments for spontaneous generation continued.

Which of the following are FALSE concerning microbes?

The primary role of microbes on the planet involves causing disease in animals and humans. This is false because only a SMALL percentage of microbes cause disease, and they are called pathogens when they are disease-causing. Most microbes play beneficial roles

Where could contamination occur if there were cracks in the curve? Would it be A,B,C,or D that causes the contamination?

The unique design of the S-shaped neck is key in preventing airborne microorganisms from reaching the sterilized beef broth. So A and B would have to be cracked because those do not have any curves to stop the microorganisms from coming in. The whole point of this experiment is the S-curve so any break past the S-curve will most likely cause contamination

Describe Louis Pastuer's flask experiment that supported German scientist's Rudolf Virchow's biogenesis

Through a series of experiments using flasks filled with beef broth placed under various conditions, Pasteur demonstrated that microorganisms are present in the air and can contaminate sterile solutions. He filled several short-necked flasks with beef broth and boiled these flasks to sterilize the contents. When left open to the air for several days, these flasks became contaminated with microorganisms. Flasks that were boiled and sealed, however, remained free of microorganisms. Pasteur reasoned that microorganisms in the air were the source of contamination.Pasteur next placed beef broth in long-necked flasks (step 1 in the figure) and bent the openings into S-shaped curves. Air could enter these flasks, but Pasteur predicted that airborne microorganisms would settle at the base of the S-shaped neck and not contaminate the beef broth. As with the previous experiment, the contents of these flasks were boiled to sterilize the broth, and samples were left open to the air (step 2 in the figure). Even after several months, the beef broth in S-shaped neck flasks did not show contamination with microorganisms (step 3).

Microbes are associated with life-sustaining benefits as well as life-threatening diseases. Is this true or false?

True some microbes are healthy while some are harmful.

A prokaryotic cell may possess each of the following cellular components EXCEPT

a nucleus

Normal microbiota

both indefinitely colonize the body and take up residence in sites such as the colon and mouth.

Viruses are not considered living organisms because they

cannot reproduce by themselves.

All microorganisms that regularly populate the human body are referred to as the ___________________.

human microbiome (by definition)

The term used to describe a disease-causing microorganism is

pathogen (there are good and bad microbes, pathogens are the one that is disease-causing)

Common commercial benefits of microorganisms include synthesis of

riboflavin, acetone and insulin

From the list below, which would NOT be considered an emerging pathogen? Avian influenza Zika virus Ebola virus Lyme disease smallpox virus

smallpox virus smallpox is forever gone thanks to vaccinations

What important theory is based on the observations of Hooke and van Leeuwenhoek, documenting the existence of microscopic cells?

the cell theory, stating that all living things are composed of cells The microscopic observations of cells form the basis of the cell theory and the idea that all living things are composed of cells; cells are the structural and functional unit of living things.

All of the following factors contribute to the threat of emerging infectious diseases (EIDs) EXCEPT __________.

vaccinations that control epidemiologic spread Vaccination does not promote emerging infections but rather helps to control infections.