Microbial Classification and Diversity quiz 1
Based on the temperature preference for many deeply branching bacteria, these bacteria are unlikely to infect and grow well inside the human body.
Answer = True Deeply-branching Evolutionarily "old" Among the first descendants of the "last universal common ancestor" (LUCA) Live in extreme environments (likely to resemble the conditions on Earth long ago) Extreme Heat
Which of the following statements is NOT true?
Answer: Archaea are more closely related (genetically) to bacteria than they are to eukaryotes. The cell walls of archaea lack peptidoglycan. Archaea are more closely related (genetically) to bacteria than they are to eukaryotes. Archaea and bacteria have different cell membrane lipids. The genomes of archaea are larger than the genomes of bacteria. How are Archaea Different from Bacteria? Archaeal cell membrane is composed of different lipids Archaeal cell walls lack peptidoglycan Genomes more complex than bacteria Archaea are not currently known to cause human disease
Which of the following traits does not apply to viruses?
Answer: Isolated virus particles conduct their own metabolism. Isolated virus particles conduct their own metabolism. Some types of viruses are enclosed by a phospholipid envelope. Viruses have a genome of nucleic acid contained by a protein capsid. Most viruses are smaller than bacterial cells. Intracellular state Capsid and envelope (if present) removed Virus exists solely as nucleic acid Virus Structure Extracellular state Called virion Capsid (protein) surrounds nucleic acid • Also called nucleocapsid • Protects genome and recognizes host • Some viruses have phospholipid envelope
Unicellular fungi such as Candida are called?
Answer: Yeast protist algae yeast protozoa Protists are unicellular eukaryotes that are not plants, animals, or fungi. Algae (singular: alga) are plant-like protists that can be either unicellular or multicellular Unicellular fungi—yeasts—are included within the study of microbiology. Protozoa, are nonphotosynthetic, motile organisms that are always unicellular. Other informal terms may also be used to describe various groups of protists.
Which group of organisms provides oxygen for us to breathe?
Answer: cyanobacteria fungi cyanobacteria bacteriodes helminthes Some bacteria are photosynthetic, such as oxygenic cyanobacteria and anoxygenic green sulfur and green nonsulfur bacteria; these bacteria use energy derived from sunlight, and fix carbon dioxide for growth.
Protozoa are best described as being?
Answer: nonphotosynthetic unicellular microorganisms nonphotosynthetic unicellular microorganisms nonphotosynthetic multicellular microorganisms photosynthetic multicellular microorganisms unicellular eukaryotes with cell walls • Unicellular eukaryotes • No cell wall • Nonphotosynthetic (most must "eat" like us) • Present in aquatic and terrestrial habitats • Important role in food chains (many are "plankton")
The nitrogen-fixing bacterium Rhizobium infects the roots of some plant species. The bacterium provides the plant nitrogen and the plant provides the bacterium carbohydrates. What type of symbiotic relationship does this describe?
Answer:Mutualism mutualism - A and B benefitted amensalism - A harmed and B unaffected commensalism - A benefitted and B unaffected neutralism - A and B unaffected Parasitism - A benefitted and B Harmed
The size of an average influenza virus is 130 nm. How would you express this size in micrometers (μm)?
Answer= .130 um meter (m) - 1m 1decimeter (dm)- 1/10 - 1 dm = 0.1 m 2centimeter (cm)- 1/100 - 1 cm = .01 3millimeter (mm) - 1/1000 - 1 mm = .001 m 6micrometer (um) - 1/1,000,000 - 1um=.000001 m 9nanometer (nm) - 1/1,000,000,000 - 1 nm = .000000001 m
Protozoa differ from bacteria in which of the following ways?
Answer= Bacteria are prokaryotic and protozoa are eukaryotic. Protists are eukaryotic, meaning that their DNA is stored in chromosomes within a nucleus. Bacteria are prokaryotic, and do not have nuclei. •Protozoa are unicellular organisms with complex cell structures; most are motile. Protozoa are nonphotosynthetic, motile organisms that are always unicellular.
Which bacterial structure do mycoplasmas lack?
Answer= Cell Wall likely Mycoplasma pneumoniae. Even though this bacterium is a prokaryotic cell, it is not inhibited by amoxicillin because it does not have a cell wall and, therefore, does not make peptidoglycan. Parker, Nina. Microbiology (p. 141). Routledge. Kindle Edition.
All Gram-negative bacteria are part of the phylum Proteobacteria.
Answer= False The majority of the gram-negative bacteria belong to the phylum Proteobacteria, discussed in the previous section. Those that do not are called the nonproteobacteria. three classes of gram-negative nonproteobacteria: the spirochetes, the CFB group, and the Planctomycetes.
The genome of a virus may consist of any of these except
Answer= Phospholipid double-stranded DNA single-stranded DNA single-stranded RNA phospholipid • Show more variety in their genomes than do cells • Primary way scientists categorize and classify viruses • Genome structure varies • May be DNA or RNA, but never both • Can be dsDNA, ssDNA, dsRNA, ssRNA • Linear or circular • Single molecule or segmented • Much smaller than genomes of cells
Viruses can have a host range that includes one species, multiple species, or specific cell types in a given species
Answer= True All organisms are susceptible to viral attack • All animals including humans can be infected with viruses • Most viruses infect only a particular host's cells • Due to affinity of viral surface proteins for complementary proteins on host cell surface • This interaction may be so specific a virus infects only a particular kind of cell in a particular host • Some viruses are generalists and can infect many kinds of cells or many different hosts
The human microbiome consists of which of the following?
Answer= all microbes present on or in the body Scientists have coined the term microbiome to refer to all prokaryotic and eukaryotic microorganisms that are associated with a certain organism. Within the human microbiome, there are resident microbiota and transient microbiota. The resident microbiota consists of microorganisms that constantly live in or on our bodies.