1.
Antoni van Leeuwenhoek was the first person in history to
Correct Answer
D. View protozoa and bacteria.
Explanation
Antoni van Leeuwenhoek was the first person in history to view protozoa and bacteria. This means that he was the first to observe these microorganisms under a microscope, which was a significant scientific achievement. It allowed for a better understanding of the microscopic world and paved the way for further discoveries in microbiology.
2.
The microbes commonly known as __________ are single -celled eukaryotes that are generally motile.
Correct Answer
D. Protozoa
Explanation
Protozoa are single-celled eukaryotes that are generally motile. They are commonly known as microbes and are distinct from viruses, bacteria, fungi, and archaea. Protozoa are characterized by their ability to move using specialized structures such as cilia, flagella, or pseudopodia. They can be found in various environments, including soil, water, and the bodies of plants and animals. Protozoa play important roles in nutrient cycling and are also known to cause diseases in humans and animals.
3.
Which of the following statements about algae is FALSE?
Correct Answer
C. They are important in the degradation of dead plants and animals.
Explanation
Algae are photosynthetic organisms that provide most of the oxygen on Earth and are a source of food for aquatic and marine animals. They also include seaweeds and kelps. However, algae are not important in the degradation of dead plants and animals. This process is primarily carried out by decomposers like bacteria and fungi.
4.
Microbes that can live in the presence or absence of oxygen are called
Correct Answer
C. Facultative anaerobes
Explanation
Facultative anaerobes are microbes that have the ability to survive in environments with or without oxygen. They can switch between aerobic respiration (using oxygen) and anaerobic respiration (not using oxygen) depending on the availability of oxygen. This flexibility allows them to adapt to different conditions and survive in a wide range of environments.
5.
Which of the following scientists provided evidence in favor of the concept of spontaneous generation?
Correct Answer
D. Needham
Explanation
Needham provided evidence in favor of the concept of spontaneous generation by conducting an experiment in which he boiled nutrient broth and sealed it in a flask. Despite the sealed flask, microorganisms still appeared in the broth, leading Needham to conclude that they must have spontaneously generated. However, this experiment was later criticized for not properly controlling for contamination, and it was ultimately Pasteur's experiments that disproved the concept of spontaneous generation.
6.
The microbial production of alcohol from sugar is known as
Correct Answer
A. Fermentation
Explanation
Fermentation is the correct answer because it refers to the microbial production of alcohol from sugar. During fermentation, microorganisms such as yeast convert sugars into alcohol and carbon dioxide through a process called anaerobic respiration. This process is commonly used in the production of alcoholic beverages such as wine, beer, and spirits.
7.
Which of the following statements about fungi is FALSE?
Correct Answer
D. Fungi are pHotosynthetic.
Explanation
The statement that fungi are photosynthetic is false. Fungi are heterotrophic organisms, meaning they obtain their nutrients by absorbing organic matter from their environment. Unlike plants, they do not have chlorophyll and cannot perform photosynthesis. Instead, they obtain energy through decomposition or by forming mutualistic relationships with other organisms.
8.
Which of the following statements concerning Kochʹs postulates is FALSE?
Correct Answer
E. A suspected pathogen must be found in the majority of individuals with a particular disease.
Explanation
Koch's postulates are a set of criteria used to determine whether a specific organism is the cause of a particular disease. According to the postulates, all of the criteria must be satisfied in order to prove causation. The false statement in this case is that a suspected pathogen must be found in the majority of individuals with a particular disease. This is not a requirement of Koch's postulates. Instead, the postulates focus on experimental infection of susceptible hosts, ability to grow the pathogen in the laboratory, and the ability to re-isolate the pathogen from the infected host.
9.
Which of the following individuals pioneered the use of chemicals to reduce the incidence of infections during surgery?
Correct Answer
E. Lister
Explanation
Lister pioneered the use of chemicals to reduce the incidence of infections during surgery. He is known for developing antiseptic techniques, including the use of carbolic acid, to sterilize surgical instruments and clean wounds. Lister's contributions greatly improved surgical outcomes and reduced the risk of post-operative infections.
10.
The study of the bodyʹs defenses against pathogens is called
Correct Answer
A. Immunology
Explanation
Immunology is the study of the body's defenses against pathogens. It focuses on understanding how the immune system recognizes and eliminates harmful substances, such as bacteria, viruses, and parasites. This field of study helps in developing vaccines, understanding autoimmune diseases, and finding ways to enhance the body's immune response. Chemotherapy is the use of drugs to treat cancer, epidemiology is the study of the distribution and determinants of health-related events in populations, molecular biology is the study of biological processes at the molecular level, and etiology is the study of the causes of diseases.
11.
Which of the following questions largely stimulated the research of microbes during what is known as the Golden Age of Microbiology?
Correct Answer
E. What causes disease, and is spontaneous generation of microbes possible?
Explanation
During the Golden Age of Microbiology, which occurred in the late 19th and early 20th centuries, scientists were primarily focused on understanding the nature of microbes and their role in causing diseases. The question "What causes disease, and is spontaneous generation of microbes possible?" captures the two main areas of research during this period. Scientists were investigating the link between microbes and diseases, as well as trying to determine whether microbes could arise spontaneously. This question reflects the key concerns and interests of researchers during the Golden Age of Microbiology.
12.
The microbial activity of __________ is responsible for the production of various foods.
Correct Answer
E. Both fungi and bacteria
Explanation
Both fungi and bacteria have a significant role in the production of various foods through their microbial activity. Fungi, such as yeast, are used in the fermentation process to produce bread, beer, and cheese. Bacteria, such as Lactobacillus, are used in the fermentation of milk to produce yogurt and other dairy products. Both fungi and bacteria play a crucial role in breaking down organic matter and converting it into edible and nutritious food products.
13.
What scientist first hypothesized that gene sequences could provide new insights into evolutionary relationships between organisms such as microbes?
Correct Answer
C. Pauling
Explanation
Linus Pauling, a renowned American chemist, is the correct answer. He is known for his significant contributions to the field of molecular biology and his work on the structure of proteins. Pauling was one of the first scientists to propose that gene sequences could be used to understand the evolutionary relationships between different organisms, including microbes. His pioneering ideas laid the foundation for the field of molecular phylogenetics, which uses genetic information to study evolutionary history.
14.
Work by __________ laid the foundations of the field of environmental microbiology.
Correct Answer
E. Beijerinck and Winogradsky
Explanation
Beijerinck and Winogradsky are credited with laying the foundations of the field of environmental microbiology. They made significant contributions to understanding the role of microorganisms in the environment, including their roles in nutrient cycling and the process of nitrogen fixation. Beijerinck is known for his work on the isolation and cultivation of bacteria, while Winogradsky is known for his studies on microbial ecology and his discovery of lithotrophy. Their work paved the way for further research in environmental microbiology and our understanding of the microbial world.
15.
Semmelweis advocated handwashing as a method of preventing which of the following diseases?
Correct Answer
D. Puerperal fever
Explanation
Semmelweis advocated handwashing as a method of preventing puerperal fever. Puerperal fever, also known as childbed fever, is a bacterial infection that occurs in women after childbirth. During Semmelweis' time, it was common for doctors to move directly from autopsies or other medical procedures to delivering babies without washing their hands, leading to the spread of bacteria and high mortality rates from puerperal fever. Semmelweis's recommendation of handwashing significantly reduced the incidence of the disease.
16.
According to Kluyver and van Niel, which of the following are true of basic biochemical reactions?
Correct Answer
A. Basic biochemical reactions shared by all living things primarily involve transfer of electrons
and hydrogen ions.
Explanation
Basic biochemical reactions shared by all living things primarily involve the transfer of electrons and hydrogen ions. This means that in these reactions, electrons and hydrogen ions are transferred between molecules. This is a fundamental process in living organisms and is essential for various metabolic pathways and energy production. The other options are not true because basic biochemical reactions do not primarily involve transfers of chemical groups, there is not an unlimited number of them, and they do not primarily involve the transfer of electrons and ions, but specifically electrons and hydrogen ions.
17.
Paul Ehrlich used chemotherapy to treat
Correct Answer
B. SypHilis
Explanation
Paul Ehrlich used chemotherapy to treat syphilis. Chemotherapy is a treatment method that involves the use of drugs to kill or inhibit the growth of cancer cells or infectious microorganisms. Syphilis is a sexually transmitted infection caused by the bacterium Treponema pallidum. Ehrlich's work in developing chemotherapy revolutionized the field of medicine and paved the way for the use of drugs to treat various diseases, including syphilis.
18.
Which of the following is NOT a characteristic of viruses?
Correct Answer
B. They are visible with a light microscope.
Explanation
Viruses are not visible with a light microscope because they are much smaller than the resolution limit of a light microscope. Viruses typically range in size from 20 to 300 nanometers, while the resolution limit of a light microscope is around 200 nanometers. Therefore, specialized microscopes such as electron microscopes are required to visualize viruses.
19.
The first true vaccine protected against disease caused by a __________ pathogen
Correct Answer
B. Viral
Explanation
The question is asking for the type of pathogen that the first true vaccine protected against. The correct answer is "viral" because vaccines were first developed to protect against viral diseases such as smallpox.
20.
All of the following individuals were involved in improving public health in the 19th century EXCEPT
Correct Answer
E. Spallanzani
Explanation
Spallanzani is the correct answer because he was not involved in improving public health in the 19th century. Although he made significant contributions to the field of biology and physiology, his work did not directly focus on public health improvements. Snow, Lister, Nightingale, and Semmelweis, on the other hand, were all influential figures in the 19th century who made significant advancements in public health through their work in epidemiology, antiseptic techniques, nursing, and hygiene practices.
21.
Saccharomyces cerevisiae is an example of which of the following types of microbes?
Correct Answer
D. Fungus
Explanation
Saccharomyces cerevisiae is a type of yeast, which is a type of fungus. This organism is commonly used in baking and brewing due to its ability to ferment sugars and produce carbon dioxide and alcohol. It is not a protozoan, prokaryote, alga, or virus.
22.
Inserting a gene from the hepatitis B virus into yeast so that the yeast produces a viral protein is an example of
Correct Answer
C. Genetic engineering
Explanation
Inserting a gene from the hepatitis B virus into yeast to produce a viral protein is an example of genetic engineering. Genetic engineering involves manipulating an organism's genetic material to create new traits or characteristics. In this case, the gene from the virus is being inserted into the yeast's genome, allowing it to produce a viral protein. This process is a common technique used in biotechnology to produce specific proteins or modify organisms for various purposes.
23.
Which of the following was NOT an aspect of Pasteurʹs experiments to disprove spontaneous generation?
Correct Answer
D. The flasks he used were sealed with corks.
Explanation
The correct answer is that the flasks he used were sealed with corks. In Pasteur's experiments, he used flasks with bent S-shaped necks to prevent airborne microbes from entering the flasks while still allowing air to flow. He also boiled the infusions to kill any existing microbes and incubated them for long periods of time to observe any growth. The fact that the flasks were free of microbes until they were opened further supported Pasteur's conclusion that spontaneous generation did not occur. The use of corks to seal the flasks would have allowed airborne microbes to enter, which goes against Pasteur's experimental design.
24.
Proteins that promote chemical reactions in the cell are called
Correct Answer
C. Enzymes
Explanation
Enzymes are proteins that act as catalysts in chemical reactions within cells. They speed up the rate of these reactions by lowering the activation energy required for the reaction to occur. Enzymes are highly specific in their function and can only catalyze specific reactions. They play a crucial role in various cellular processes such as metabolism, DNA replication, and protein synthesis. Therefore, enzymes are the proteins that promote chemical reactions in the cell.
25.
Which of the following is NOT a characteristic of protozoa?
Correct Answer
A. They are the microbes most similar to plants.
Explanation
Protozoa are eukaryotic organisms that are single-celled and frequently possess cilia or flagella. Most protozoa exhibit asexual reproduction. However, they are not the microbes most similar to plants. This statement is incorrect because protozoa are more similar to animals than plants.
26.
Which of the following is NOT an observation Pasteur made concerning the fermentation of grape juice?
Correct Answer
E. Pasteurization kills yeast to prevent spoilage of grape juice.
Explanation
Pasteur made several observations concerning the fermentation of grape juice, including the fact that yeast can grow with or without oxygen, yeast can grow in sealed or open flasks of grape juice, yeast cells can grow and reproduce in grape juice, and bacteria produce acid in grape juice. However, Pasteur did not observe that pasteurization kills yeast to prevent spoilage of grape juice.
27.
Which of the following scientists was the first to develop a taxonomic system for classifying organisms?
Correct Answer
E. Linnaeus
Explanation
Linnaeus was the first scientist to develop a taxonomic system for classifying organisms. His system, known as binomial nomenclature, involved giving each species a unique two-word Latin name consisting of its genus and species. This system revolutionized the field of biology and is still widely used today.
28.
Put the following events in the history of microbiology in order, from the earliest to the latest:
I. Leeuwenhoek observes microbes using a microscope.
II. Pasteur disproves spontaneous generation.
III. Woese discovers the archaea.
IV. Fracastoro proposes that ʺgermsʺ cause disease.
V. Ehrlich discovers the first ʺmagic bullet.ʺ
Correct Answer
D. IV, I, II, V, III
Explanation
The correct order of events in the history of microbiology is as follows: Fracastoro proposes that "germs" cause disease (IV), Leeuwenhoek observes microbes using a microscope (I), Pasteur disproves spontaneous generation (II), Ehrlich discovers the first "magic bullet" (V), and Woese discovers the archaea (III). This order represents the chronological progression of significant discoveries and advancements in the field of microbiology.
29.
John Snowʹs research during a cholera outbreak in London laid the foundation for which of the following branches of microbiology?
Correct Answer
D. Both infection control and epidemiology
Explanation
John Snow's research during a cholera outbreak in London laid the foundation for both infection control and epidemiology. His study of the outbreak led him to discover that contaminated water was the source of the disease, which contributed to the development of infection control measures to prevent the spread of infectious diseases. Additionally, his work in mapping the cases of cholera and identifying patterns of transmission laid the groundwork for the field of epidemiology, which focuses on studying the distribution and determinants of diseases in populations.
30.
Robert Koch was involved in research on all of the following topics EXCEPT
Correct Answer
D. The cause of fermentation.
Explanation
Robert Koch was involved in research on the cause of anthrax, techniques for isolating microbes in the laboratory, the cause of tuberculosis, and the development of a method to prove the cause of an infectious disease. However, there is no evidence to suggest that he was involved in research on the cause of fermentation.
31.
Which of the following is an INCORRECT pairing?
Correct Answer
D. Protozoa: multicellular
Explanation
The pairing of "protozoa: multicellular" is incorrect because protozoa are actually unicellular organisms, not multicellular. Protozoa are a diverse group of eukaryotic microorganisms that typically live in aquatic environments. They are known for their ability to move and capture food using specialized structures like cilia or flagella. However, they are composed of a single cell and do not form multicellular organisms.
32.
What was the first disease proven to be bacterial in origin?
Correct Answer
E. Anthrax
Explanation
Anthrax was the first disease proven to be bacterial in origin. Louis Pasteur and Robert Koch independently discovered the bacterium responsible for anthrax in the late 19th century. They demonstrated that the disease was caused by the bacterium Bacillus anthracis, which forms spores that can survive in the environment for long periods. This groundbreaking discovery paved the way for the understanding of other bacterial diseases and the development of vaccines and treatments.
33.
The work of Lister, Nightingale, and Semmelweis all contributed to controlling infectious disease by
Correct Answer
D. Developing methods for reducing nosocomial infections.
Explanation
The work of Lister, Nightingale, and Semmelweis all contributed to controlling infectious disease by developing methods for reducing nosocomial infections. Lister introduced antiseptic techniques, Nightingale emphasized the importance of cleanliness and hygiene in hospitals, and Semmelweis advocated for handwashing to prevent the spread of infection. These methods aimed to reduce infections acquired in healthcare settings, which are known as nosocomial infections. By implementing these practices, the risk of transmission of infectious agents within hospitals and healthcare facilities was significantly reduced.
34.
Who discovered penicillin?
Correct Answer
B. Fleming
Explanation
Alexander Fleming is credited with the discovery of penicillin. In 1928, he noticed that a mold called Penicillium notatum had contaminated one of his petri dishes and was inhibiting the growth of bacteria. This accidental discovery led to the development of the first antibiotic, penicillin, which revolutionized medicine and saved countless lives. Fleming's work laid the foundation for the field of antibiotics and he was awarded the Nobel Prize in Physiology or Medicine in 1945 for his discovery.
35.
All of the following were involved in developing the germ theory of disease EXCEPT
Correct Answer
B. Pauling
Explanation
The germ theory of disease states that microorganisms, specifically bacteria and viruses, are the cause of many diseases. Snow, Pasteur, Koch, and Fracastoro were all key figures in the development of this theory. However, Pauling, who was a renowned chemist and biochemist, is not typically associated with the germ theory of disease. His work primarily focused on the field of molecular biology and his contributions were more related to the study of proteins and genetic disorders. Therefore, Pauling is the correct answer as he was not involved in developing the germ theory of disease.
36.
Microorganisms characterized by the absence of a nucleus are called
Correct Answer
E. Prokaryotes
Explanation
Prokaryotes are microorganisms that lack a nucleus. They are unicellular organisms that do not have a membrane-bound nucleus or other membrane-bound organelles. Instead, their DNA is located in the cytoplasm. Prokaryotes include bacteria and archaea. Eukaryotes, on the other hand, have a true nucleus and include organisms such as plants, animals, fungi, and protists. Viruses are not considered living organisms as they are acellular and cannot reproduce on their own. Pathogens are disease-causing microorganisms, which can include both prokaryotes and eukaryotes. Fungi are eukaryotic organisms that have a nucleus.
37.
The term that literally means ʺagainst putrefactionʺ is
Correct Answer
D. Antisepsis
Explanation
Antisepsis refers to the process of preventing the growth or spread of microorganisms, particularly those that cause infection or putrefaction. The term "against putrefaction" suggests that the purpose of antisepsis is to inhibit the decomposition or decay of organic matter, which is caused by the action of bacteria and other microorganisms. Therefore, the correct answer is antisepsis.
38.
The term __________ refers to an infection acquired in a health care setting.
Correct Answer
C. Nosocomial
Explanation
The term "nosocomial" refers to an infection acquired in a healthcare setting. This means that the infection is contracted while receiving medical care in a hospital, clinic, or other healthcare facility. Nosocomial infections are often caused by bacteria or viruses that are resistant to antibiotics and can spread easily in healthcare settings, posing a risk to patients and healthcare workers. It is important for healthcare facilities to have strict infection control measures in place to prevent the spread of nosocomial infections.
39.
The term __________ literally means ʺproduces disease.ʺ
Correct Answer
C. Pathogen
Explanation
The term "pathogen" refers to a microorganism or agent that is capable of causing disease. It is derived from the Greek words "pathos," meaning disease, and "gen," meaning producer or creator. Therefore, the term "pathogen" literally means "produces disease."
40.
The study of the causation of disease is known as
Correct Answer
D. Etiology
Explanation
Etiology is the study of the causation of disease. It focuses on identifying the factors and mechanisms that contribute to the development of diseases. By understanding the etiology of a disease, researchers can gain insights into how it is caused, which can lead to the development of prevention strategies and targeted treatments. Immunology, epidemiology, biotechnology, and chemotherapy are all related fields in healthcare, but they do not specifically focus on the causation of disease like etiology does.
41.
The term for the use of microorganisms to restore damaged environments is
Correct Answer
A. Bioremediation
Explanation
Bioremediation refers to the use of microorganisms to restore damaged environments. This process involves the use of bacteria, fungi, or other microorganisms to break down pollutants and contaminants, converting them into less harmful substances. By harnessing the natural abilities of these microorganisms, bioremediation can help clean up polluted soil, water, and air, making it an effective method for environmental restoration.
42.
The term __________ means the study of the blood components that fight infection.
Correct Answer
E. Serology
Explanation
Serology is the correct answer because it refers to the study of blood components that fight infection. Serology involves the examination of blood serum and the detection of antibodies, which are produced by the immune system in response to an infection. By studying these antibodies, serology helps in diagnosing and monitoring various infectious diseases.
43.
The study of the occurrence, distribution, and spread of disease is known as
Correct Answer
C. Epidemiology
Explanation
Epidemiology is the study of the occurrence, distribution, and spread of diseases in populations. It focuses on understanding the patterns and causes of diseases, as well as developing strategies for prevention and control. This field uses various research methods and statistical analysis to investigate disease outbreaks, identify risk factors, and inform public health interventions. By studying epidemiology, scientists and healthcare professionals can better understand how diseases are transmitted, develop effective prevention measures, and improve overall population health.
44.
The taxonomic scheme developed by Linnaeus remains largely unchanged in modern biology.
Correct Answer
B. False
Explanation
The taxonomic scheme developed by Linnaeus has undergone significant changes in modern biology. Linnaeus' system of classification was based primarily on observable physical characteristics, whereas modern taxonomy incorporates genetic and molecular data. Additionally, advancements in technology and scientific understanding have led to the discovery of new species and the reclassification of existing ones. Therefore, it can be concluded that the taxonomic scheme developed by Linnaeus is not largely unchanged in modern biology.
45.
Christian Gram devised a staining technique that divides all bacteria into two groups.
Correct Answer
A. True
Explanation
Christian Gram devised a staining technique called the Gram stain, which is used to divide bacteria into two groups based on their cell wall composition. This technique involves staining bacteria with crystal violet dye, followed by the application of iodine, and then a decolorizing agent. Bacteria that retain the crystal violet stain after decolorization are called Gram-positive, while those that do not retain the stain are called Gram-negative. Therefore, the statement that Christian Gram devised a staining technique that divides all bacteria into two groups is true.
46.
The production of human blood-clotting factor by E. coli is an example of bioremediation.
Correct Answer
B. False
Explanation
The production of human blood-clotting factor by E. coli is not an example of bioremediation. Bioremediation refers to the use of living organisms to clean up or remove pollutants from the environment. In this case, the production of human blood-clotting factor is a biotechnological application, not a method of environmental cleanup.
47.
Walter Reed proved that a virus causes yellow fever in humans.
Correct Answer
A. True
Explanation
Walter Reed's research and experiments provided evidence that a virus is the cause of yellow fever in humans. His findings were significant in establishing the link between the virus and the disease. This breakthrough in understanding the etiology of yellow fever paved the way for further research and the development of preventive measures and treatments for the disease.
48.
Gene therapy is a modern approach to preventing infectious disease.
Correct Answer
B. False
Explanation
Gene therapy is not a modern approach to preventing infectious disease. Gene therapy is a medical technique that involves introducing genetic material into a person's cells to treat or prevent a disease. It is primarily used for genetic disorders, not infectious diseases. Preventing infectious diseases typically involves measures like vaccination, good hygiene practices, and public health interventions.
49.
Kochʹs postulates can be used only to prove the causes of infectious diseases.
Correct Answer
A. True
Explanation
Koch's postulates are a set of criteria used to establish a causal relationship between a microorganism and a specific disease. These postulates require that the microorganism be consistently present in individuals with the disease, that it can be isolated and grown in pure culture, that it can cause the disease when introduced into a healthy individual, and that it can be re-isolated from the newly infected individual. Therefore, Koch's postulates can only be used to prove the causes of infectious diseases, making the statement true.
50.
Joseph Lister reduced the incidence of wound infections in health care settings by using chlorinated lime water.
Correct Answer
B. False
Explanation
Joseph Lister actually reduced the incidence of wound infections in healthcare settings by using carbolic acid (phenol) as an antiseptic, not chlorinated lime water. Chlorinated lime water was not effective in preventing infections, while carbolic acid was proven to be effective in killing bacteria and preventing wound infections.