Unit 11 Bio Test Flashcards
Which of the following can be effective in preventing viral infection in humans? A) taking antibiotics B) getting vaccinated C) taking vitamins D) applying antiseptics
B) getting vaccinated
What is the basic structure of virus?
DNA or RNA surrounded by a protein coat
What is the most probable fate of a newly emerging virus that causes high mortality in its host?
the newly emerging virus will die out rather quickly or will mutate to be far less lethal
Which of the following will NOT prevent many bacterial infections?
A) allowing foods to cool completely before refrigerating
B) heating objects to very high temperatures
C) storing food in a refrigerator
D) washing hands and surfaces with soap and water
A) allowing foods to cool completely before refrigerating
Photo-autotrophs use _________________.
light as an energy source and CO2 as a carbon source
If new genetic variation in the experimental populations arose solely by spontaneous mutations, then the most effective process for subsequently increasing the prevalence of the beneficial mutations in the population over the course of generations is __________.
binary fission
Which of the following can survive either with or without oxygen? A) facultative anaerobes B) obligate aerobes C) obligate anaerobes D) bacteriophages
A) facultative anaerobes
Proteins in the viral capsid or on the surface membrane function to ____________.
bind the virus to the surface of a host cell
During a lytic infection, the host cell __________.
is destroyed when it bursts
The outer protein coat of a virus is called a _________.
capsid
Regarding prokaryotic reproduction, which statement is correct?
A) prokaryotes form gametes by meiosis
B) mutation is a primary source of variation in prokaryote populations
C) prokaryotes skip sexual life cycles because their life cycle is too short
D) prokaryotes exchange some of their genes by conjugation, the union of haploid gametes, and transduction
B) mutation is a primary source of variation in prokaryote populations
Which of the following is characteristic of the lytic cycle?
A) viral DNA is incorporated into the host genome
B) a large number of phages
C) the viral genome replicates without destroying the host
D) many bacterial cells containing viral DNA are produced
B) a large number of phages is released at a time
1) autotroph
2) heterotroph
3) phototroph
4) chemotroph
Which organism(s) relies on photons to excite electrons within its membrane?
3) phototroph
1) autotroph
2) heterotroph
3) phototroph
4) chemotroph
Which organism(s) obtains its energy from chemicals?
4) chemotroph
What is the reasoning behind the fact that someone that has had a herpesvirus cold sore once will get flare-ups repeatedly throughout the rest of their life?
copies of the herpesvirus genome is permanently maintained in the host’s nuclei
What three characteristics are used to classify prokaryotes?
1) shape
2) movement
3) how they get energy
What is the host range of a virus determined by?
the proteins the surface of the virus’ cell and the host’s cell
Escherichia coli is classified as a ___________.
bacterium
Penicillin is an antibiotic that inhibits the enzymes from catalyzing the synthesis of peptidoglycan, so which prokaryotes should be most vulnerable to inhibition by penicillin?
gram-positive bacteria
What is the primary ecological role of prokaryotes?
breaking down organic matter
Unlike lytic viruses, lysogenic viruses DO NOT ____________.
lyse the host cell right away
What is the name given to viruses that are single-stranded RNA that acts as a template for DNA synthase?
retroviruses
A specific thermoacidophile lacks a peptidoglycan, what is likely to be true about this species?
1) it is a bacterium
2) it is an archaean
3) the optimal pH of its enzymes will lie above pH 7
4) the optimal pH of its enzymes will lie below pH 7
5) it could inhabit certain hydrothermal springs
6) it could inhabit alkaline hot springs
2,4,5
Which bacterial structure acts as a selective barrier, allowing nutrients to enter the cell and wastes to leave the cell?
plasma membrane
Though plants, fungi, and prokaryotes all have cell walls, we place them in different taxa. Before we had the relevant data from molecular systematics, what was the reasoning behind this?
their cell walls are made of very different biochemicals
What three materials make up many viruses?
proteins, nucleic acids, and lipids
Many physicians administer antibiotics to patients at the first sign of any disease symptoms. Why can this practice cause more problems for these patients, and for others not yet infected?
overuse of antibiotics can select for antibiotic-resistant strains of bacteria
During an experiment, a scientist observed prokaryotes that lived near volcanic vents deep in the ocean. The scientist MOST likely observed ___________.
chemoautotrophs
Viral diseases can be ________ with vaccines but not _________ with antibiotics.
1) prevented
2) treated
Which statement about prokaryotes is correct?
A) bacterial cells conjugate to mutually exchange genetic material
B) the persistence of bacteria throughout evolutionary time is due to their genetic homogeneity (i.e. sameness)
C) their genetic material is confined within a nuclear envelope
D) they divide by binary fission, without meiosis or mitosis
D) they divide by binary fission, without meiosis or mitosis
If all prokaryotes on Earth suddenly vanished, what would be the most likely and direct result?
the recycling of nutrients would be greatly reduced, at least initially
Most human-infecting viruses are maintained in the human population only. However, a zoonosis is a disease that is transmitted from the other vertebrates to humans, at least sporadically, without requiring viral mutation. Which is the best example of a zoonosis? A) rabies B) herpesvirus C) HIV D) smallpox
A) rabies
How do bacteria cause disease?
by destroying cells and releasing toxins
What makes up the viral envelope?
glycoproteins
Which if the following characteristics of livings things is NOT true about viruses? A) evolve over time B) able to reproduce C) obtain and use energy D) contain genetic material
C) obtain and use energy
What kind of pathogen causes clumps of misfolded proteins to form in the brain?
prions
What is the function of reverse transcriptase in retroviruses?
it uses viral RNA as a template for DNA synthesis
Genetic variation in bacterial populations cannot result from _________.
binary fission
Which if the following may be members of the kingdom Archaea? A) eukaryotes B) methane producers C) bacteria D) E. coli
B) methane producers
Which of the following traits do archaeans and bacteria share?
1) composition of the cell wall
2) presence of plasma membrane
3) lack of a nuclear envelope
4) identical rRNA sequences
2,3
How do viruses cause disease?
by destroying cells or affecting cellular processes
Which of the following characteristics, structures, or processes is common to both bacteria and viruses?
A) metabolism
B) genetic material composed of nucleic acid
C) ribosomes
D) cell division
B) genetic material composed of nucleic acid
What is the most common compound in the cell walls or a gram-positive bacteria?
peptidoglycan
What are the three possible shapes of bacteria?
coccus
bacillus
spirillus
Bacteria that cause disease are called _______.
pathogens
