Question: Which type of prokaryotes are able to live in the most extreme environments?

Answer: archaea

Question: Which of the following describes the archaea?

Answer: All of the answer choices describe the archaea.- methanogens- halophiles-thermoacidophiles- prokaryotes

Question: Which relationship is correct?

Answer: thermoacidophiles—hot, acidic environments

Question: Which of the following is a true statement about bacteria?

Answer: All of the answer choices are true statements about bacteria.- Bacteria lack mitochondria.- Bacteria lack a nucleus but have DNA.- Bacteria occur in three basic shapes.- Bacteria have a single circular chromosome.

Question: Which of the following terms would describe a chain of rod-shaped bacterial cells?

Answer: streptobacilli

Question: What differentiates Gram-positive and Gram-negative bacteria?

Answer: whether their cell walls have a thin or thick layer of peptidoglycan

Question: Which type of organism will form endospores when faced with unfavorable environmental conditions?

Answer: bacteria

Question: Which statement is true about bacteria?

Answer: Bacteria contain a single, circular chromosome.

Question: Which of the following describes the process of transformation?

Answer: live bacterium picks up DNA from a dead bacterium

Question: A virus carries a piece of bacteria DNA from one bacterium to another in a process called

Answer: transduction.

Question: One bacterial cell passes DNA to a second cell through a sex pilus in the process of

Answer: conjugation.

Question: Which of the following is considered a method of horizontal gene transfer in bacteria?

Answer: conjugation, transformation, and transduction

Question: Antibiotics are used to treat

Answer: bacterial infections.

Question: Which two domains do the prokaryotes belong?

Answer: Archaea and Bacteria

Question: Metabolically, archaea

Answer: can be heterotrophic or autotrophic.

Question: How are the archaea different from bacteria?

Answer: Archaea have a monolayer of lipids with branched side chains.

Question: Which organisms form lichens?

Answer: cyanobacteria and fungi

Question: Which statement is true about cyanobacteria?

Answer: All of the answer choices are true statements about cyanobacteria.- They are sometimes erroneously called blue-green algae.- They can form toxic blooms in water enriched with nutrients.- They can combine with fungi to form lichens.- They can colonize rocks.

Question: Which of the following associations is correct?

Answer: herpesvirus—chickenpox

Question: Which of the following is considered to be acellular?

Answer: viruses

Question: Which of these is the most accurate description of a virus?

Answer: chemical complexes of RNA or DNA protected by protein

Question: The core of a virus contains

Answer: either DNA or RNA.

Question: Which of the following is true about viruses?

Answer: All of the answer choices are true statements about viruses.- The genome may be DNA or RNA.- The nucleic acid may be single or double stranded.- Viruses exhibit host specificity.- Viruses are obligate intracellular parasites.

Question: The capsid of a virus is composed of

Answer: protein.

Question: Some viruses contain which of the following structures on their outer surface?

Answer: a membranous envelope composed of the host's plasma membrane

Question: In order to infect a cell, a virus must

Answer: have a special protein spike on its surface capsid that can interact with a receptor protein on the surface of the host cell.

Question: Which stage of viral reproduction takes place when the spikes of the virus bind to a specific receptor molecule on the surface of a host cell?

Answer: attachment stage

Question: Most viruses are

Answer: much smaller than bacteria.

Question: If a virus is latent

Answer: the viral genome is reproduced along with the host cell.

Question: The life cycle stage of an animal virus during which a mature capsid forms around copies of the viral RNA genome is

Answer: assembly

Question: Which of the following is a characteristic of bacteria but not viruses?

Answer: Diseases caused by them may be treatable with antibiotics.

Question: Which of the following is a true statement about retroviruses?

Answer: All of the answer choices are true statements about the retroviruses.- they contain the enzyme reverse transcriptase- it is able to carry out transcription of RNA to DNA- viral DNA remains in the host genome- can be hidden from the host immune system

Question: Just after entering a cell, a virus

Answer: loses its protein capsid and the viral genome is exposed.

Question: When small mutations gradually change the surface antigens of a virus so that antibodies to the original virus become less effective, this is known as

Answer: antigenic drift.

Question: Naked strands of RNA not covered by a capsid are

Answer: viroids.

Question: Proteinaceous infectious particles that cause degenerative diseases of the nervous system in humans and other animals are called

Answer: prions.

Question: Bovine spongiform encephalopathy (BSE), or "mad cow disease," is caused by a(n)

Answer: prion.

Question: Which of the following groups has a membrane composed of a monolayer of lipids with branched side chains that helps some members of the group tolerate acid and heat?

Answer: archaea

Question: Which statement is true about prion diseases?

Answer: All of the answer choices are true statements about prions.- Prions are believed to cause Creutzfeldt-Jakob disease (CJD).- Prions are misshapen proteins that cause other proteins to change shape.- Mad cow disease (BSE) is spread by consumption of cattle feed contaminated with prions.- The buildup of these abnormal proteins cause a loss of neurons

Question: Antonie van Leeuwenhoek was a Dutch tradesman and scientist who is famous for inventing the microscope.

Answer: FALSE

Question: Louis Pasteur conducted an experiment to answer the question of whether or not living things can arise spontaneously from nonliving materials. In this experiment, he used two flasks of sterile broth. What were the results of this experiment?

Answer: In the flask with the curved neck, no growth occurred. However, growth did occur in the flask that allowed outside air to enter, demonstrating that living things came from outside the sterile broth.

Question: In addition to his work with bacteria, Louis Pasteur also suggested that something even smaller than a bacterium was the cause of rabies. What did Louis Pasteur accomplish that furthered our understanding of viral diseases?

Answer: He developed a vaccine that he used to save a young boy that had contracted rabies.

Question: Microbiology is the study of microbes. Which of the following is considered a microbe?

Answer: All of the answer choices are microbes.- archae- protists- viroids- bacteria

Question: Although microbes are often equated with pathogens, not all are pathogenic and some help humans maintain their health. Which of the following are synthesized by bacteria that live in the human intestine?

Answer: vitamins K and B12

Question: Bacteria can be beneficial in which of the following ways?

Answer: All of the answer choices describe ways that bacteria can be beneficial.- They can be used to clean up an oil spill in a process called bioremediation.- They can be used in industry to generate products, particularly in food processing.- They are present on the skin and help crowd out harmful bacteria.- They function in wastewater purification to remove both organic and inorganic substances.

Question: Bacteria cause diseases in humans when they

Answer: carry the genes that code for virulent factors, causing them to be harmful to humans.

Question: Which genus of bacteria causes more diseases in humans than any other?

Answer: Streptococcus

Question: Pathogenic bacteria are becoming increasingly deadly because

Answer: antibiotic resistance is becoming more and more common due to humans taking unnecessary antibiotics.

Question: What form of energy did the electric spark in the Miller-Urey experiment simulate?

Answer: lightning

Question: Which of the following forms of energy is thought to have been involved in the production of large organic molecules in the primitive reducing atmosphere?

Answer: All of the answer choices describe forms of energy that could have contributed to the production of large organic molecules on early Earth.- radioactivity- electrical energy- heat- radiation from the sun

Question: Which of the following molecules is thought to have been absent from the primitive reducing atmosphere of early Earth?

Answer: oxygen (O2)

Question: Miller's laboratory experiments showed that

Answer: the primitive gases can react together to produce small organic molecules.

Question: Which of the following is the correct order, from simple to complex, showing the origin of life?

Answer: C, H, O, N → CH4 and NH3 → amino acids → proteins

Question: Which of the following scientist(s) received a Nobel Prize in Chemistry for their discovery that RNA can be both a substrate and an enzyme?

Answer: Thomas Cech and Sidney Altman

Question: The hypothesis that RNA and polypeptides evolved simultaneously was proposed by

Answer: Alexander Cairns-Smith.

Question: The protein-first hypothesis

Answer: suggests that sophisticated enzymes with the ability to synthesize DNA and RNA arose first from small molecules provided by the ocean.

Question: If the hypothesis that protocells arose in a "RNA world" is correct, which of the following would be necessary to shift to a "DNA world"?

Answer: All of the answer choices list enzymes that would be necessary for a shift from an RNA world to a DNA world.- an enzyme or reaction capable of converting ribose to deoxyribose in nucleotides- enzymes for reverse transcription of RNA into DNA- new enzymes to replicate the DNA- new enzymes for transcribing DNA back to RNA

Question: The fact that a nucleic acid is a very complicated molecule suggests that

Answer: RNA could not have arisen on its own by chance, but required enzymes to guide the synthesis of nucleotides and nucleic acids.

Question: The synthesis of DNA or RNA from the organic soup would have been guided by the actions of enzymes in the

Answer: protein-first hypothesis.

Question: Which hypothesis suggests that both polypeptides and RNA arose at the same time?

Answer: Alexander Cairns-Smith's simultaneous evolution of polypeptides and RNA hypothesis

Question: Liposomes are composed of

Answer: lipids.

Question: Which of the following is a true statement about protobionts (protocells)?

Answer: They represent stage 3 in the evolution of life.

Question: One hypothesis suggests that protobionts were heterotrophs, organisms that synthesized organic molecules from inorganic molecules and nutrients.

Answer: FALSE

Question: The central dogma of genetics states that DNA directs protein synthesis and that information flows from

Answer: DNA → RNA → protein.

Question: Biological evolution (the evolution of living cells) differs from chemical evolution (the evolution of the molecules that make living cells) in that biological evolution would have been possible only after the development of

Answer: a membrane.

Question: What general feature defines an organism as a microbe?

Answer: generally require a microscope to be seen

Question: Which of the following is a benefit of microbes?

Answer: All of the answer choices are benefits of microbes.- break down organic molecules- Various microbes help protect us from harmful microbes.- aid in digestion- synthesize vitamins K and B12

Question: Which feature is lacking in the cell wall of archaea that will distinguish them from the bacteria?

Answer: peptidoglycan

Question: What feature enables the archaea to survive in harsh environments?

Answer: their plasma membranes and cell walls

Question: The plasma membrane of archaea is composed of a phospholipid bilayer.

Answer: FALSE

Question: Which description best fits a chemoautotroph bacteria?

Answer: They reduce carbon dioxide to an organic compound by using energetic electrons derived from chemicals.

Question: Most bacteria are heterotrophs that require an outside source of organic compounds in the same way animals do.

Answer: TRUE