Ch 19 Flashcards
Which structure helps bacteria to attach within the tissues that they will infect? Flagella Cell wall Capsule Nucleoid
Capsule -
The gelatinous capsule that covers some bacteria helps them attach to the tissues that they will infect
True or false. Bacteria reproduce by an asexual process in which one parent cell gives rise to identical daughter cells.
True-
Bacteria reproduce by binary fission, which is an asexual process in which one parent cell splits in two to give rise to identical daughter cell
The genetic material of HIV consists of \_\_\_\_\_. single-stranded DNA single-stranded RNA double-stranded DNA double-stranded RNA none of the above
single-stranded RNA-
The genetic material of HIV consists of two molecules of single-stranded RNA
What is the function of reverse transcriptase?
It catalyzes the formation of a polypeptide from an RNA template.
It catalyzes the formation of DNA from a polypeptide template.
It catalyzes the formation of RNA from a polypeptide template.
It catalyzes the formation of RNA from a DNA template.
It catalyzes the formation of DNA from an RNA template
It catalyzes the formation of DNA from an RNA template.
What is the source of a viral envelope?
host cell DNA
prophages
provirus
host cell membrane
viral glycoproteinshost cell membrane-
The viral envelope is derived from host cell membrane.
Double-stranded viral DNA is incorporated into a host cell as a \_\_\_\_\_. promoter provirus transposon lac homeoboxes
provirus-
“Provirus” is the name given to double-stranded viral DNA that has been incorporated into a host cell’s genome.
Peptidoglycan is found in the cell walls of bacteria. fungi. plants. viruses. archaea.
bacteria.
You discover a new "particle." It has only RNA as a nucleic acid and lacks both a membrane and cytoplasm. This "particle" is a(n) archaea. prion. virus. fungus. bacteria
virus
Unlike aerobic prokaryotes, anaerobic prokaryotes can obtain energy when ________ is not available.
oxygen
Cyanobacteria obtain energy through ________.
photosynthesis
Bacterial endospores are used for
forming biofilms.
bacterial reproduction.
bioremediation.
keeping the bacteria alive under harsh conditions.
attracting viruses.keeping the bacteria alive under harsh conditions
Dental plaque is an example of
bacterial flagella.
a cell membrane.
an endospore.
beneficial bacteria.
a biofilm.a biofilm
A bacterium capable of causing disease in a host is a(n) ________.
pathogen
Through which process are bacteria able to exchange genetic material? Anaerobic respiration Conjugation Endospore formation Sexual reproduction Photosynthesis
Conjugation
In bacteria, the small, circular pieces of DNA that are located outside the chromosome are called sex pili. endospores. flagella. plasmids. bacteriophages.
plasmids.
Mutations that improve the survival and reproduction of organisms, and thus contribute to the evolution of species, arise rapidly in prokaryotes due to their anaerobic metabolism. cell wall composition. absence of a nucleus. rapid rate of cell division. sexual reproduction.
rapid rate of cell division
The use of bacteria to break down pollutants is referred to as nitrogen-fixation. binary fission. bioremediation. biosynthesis. biofixation.
bioremediation.
To limit your risk from foodborne bacteria, you should
eat only uncooked eggs.
cook foods thoroughly.
thaw frozen foods at room temperature.
keep foods at or above room temperature.
avoid refrigerating foods.
cook foods thoroughly.
In which of these environments would you normally find prokaryotes?
An animal’s intestinal tract
A single drop of seawater
Human skin
A spoonful of soil
All of the above - just about everywhere
All of the above - just about everywhere
Antibiotics can be effective only against a prion. bacterium. virus. viroid
bacterium.
All bacteria are harmful to humans. True or False?
False
How does a bacterium survive long periods of desiccation?
Endospores that encase the genetic information, burst, and wait until good conditions to return to bacterial form
How does biofilms help bacteria?
It provides a sticky slime layer that defends against antibiotics and disinfectants but allow bacteria to easily adhere to surfaces.
Through what structure do bacteria exchange genetic information?
plasmid- a small circular DNA molecule separate from bacteria chromosome may carry resistance gene to antibiotics - through the cytoplasm
How does facultative anaerobic survive when there is no Oxygen available?
by anaerobic fermentation
Sulfur bacteria uses what instead of water for photosynthesis?
H2S hydrogen sulfide
What are cyanobacteria?
bacteria that use photosythesis and have chlorophyll (used to be green algae)
What are 2 important roles of bacteria in ecosystems?
- help give nutrients back to the environment
2. break down, recycle waste, and dead organisms
Mention different bacterial shapes
spherical
rod-shaped
corkscrew
How are bacteria and archae similar; how are they different
similar- reproduction, motive for movement, look
different- composition of ribosomes, composition of cell wall (bacteria has peptidoglycan)
How does the flagelum of a prokaryote move?
In circles from a wheel/axle to propel itself
How does bacteria obtain energy and nutrients?
bioremediation-
manipulating conditions to stimulate breakdown of pollutants.
What are nitrogen-fixing bacteria and what role do they play in ecosystems?
bacteria that lives in soil and specialized nodules. They capture nitrogen in the soil then then combine it with hydrogen to move (NH4) that plants can use directly
In what types of extreme environments can bacteria live?
extreme heat, col, dry, wet, high salt, acidic, alkaline, high pressure
What is the mechanism of bacterial reproduction?
Prokaryotic (binary) fission- identical asexual copies
Do bacteria reproduce sexually? What is conjugation?
No asexually
transfer of DNA to another cell through a cytoplasmic bridge that contains the plasmid
What accounts for creation of new types of bacteria?
Quick replication of cells thus causing higher chance for DNA mutation
Mention some diseases caused by bacteria
tetanus, Lyme disease, cholera. syphilis, bubonic plague, TB, pneumonia
Mention ways in which bacteria benefit humans
recycle waste
capture nitrogen
clean up pollution
Why are viruses considered not alive?
- have no ribosomes
- No cytoplasm
- Cannot synthesize organic molecules
- Cannot extract or use stored energy
- No membrane
- Can not reproduce on there own
What are the 2 main parts of a virus and their function? What other parts can they have?
molecule of hereditary material
coat of protein surrounding molecule
can have a envelope sometimes
Why are viruses considered parasites?
viruses are non-living and NEED a host cell
What are the main types of genetic material in viruses?
DNA- double strand
RNA- Single and double (during reverse transcription)
How specific is the relationship between a virus and its host? What characteristic contributes to this specificity?
Viruses are very picky about host cell. (like a lock and key)
they attack specific cell types- nerve cells, respiratory tract cells, white blood cells
What is the general sequence of steps in viral replication?
- attach/penetrate
- uncoating/burst
- transcription/translation
- assemble/release
Mention how a retrovirus is different from other viruses.
It takes RNA through reverse transcriptase to produce DNA which in turn will cause transcription ( DNA- RNA- Protein retrovirus cell)
What is a viroid and what is a prion?
viroid- infectious particles that only contain circular strands of RNA
Prion- infectious protein (agent) with no nucleic acid
How are the lytic and lysogenic cycles different?
lytic takes over bacteria cell reproduces then destroys host
lysogenic incorporates DNA with host cell DNA to become a part of it and remains “dormant” within chromosomes
\_\_\_\_ is the substance that differentiates a bacterial cell from a archaeal cell bacterium plasma peptidoglycan cytoplasm
peptidoglycan
Classification of prokaryotes may use many kinds of traits. Which of these are NOT used in prokaryotic classification? cell shape means of locomotion nutrient sources staining properties type of nucleic acid
type of nucleic acid- no nucleus
Which of the following traits allows some bacteria to survive extreme conditions for millions of years? aerobic respiration endospore formation conjugation binary fission
endospore formation
Hospitals must sterilize surgical instruments at very high temperatures and pressure because some bacteria can survive harsh conditions by making \_\_\_\_\_ zygotes endospores seeds fruiting bodies basidiospores
endospores
The technique that helps to classify bacteria based on their cell-wall construction is \_\_\_ iodine stain carbon stain gram stain cytoplasmic stain
gram stain
what type of bacteria are photosynthetic?
prokaryotic methanogens
cyanobacteria
sulfur bacteria
both the first and third answers are correct
both the second and third answers are correct
both the second and third answers are correct
Which of the following enable plants to obtain a usable form of nitrogen? bacteria viruses prions zooflagellates
bacteria
The simple form of cell division by which prokaryotic cells reproduce is called \_\_\_ binary fission conjugation endospore formation mitosis
binary fission
A particle between 0.05 and 0.2 microns containing genetic material enclosed in a protein coat is called a \_\_\_\_ virus parasite microbe atom
virus
viruses are not cellular and are often considered to be non-living. Which of the following characteristics supports this conclusion?
viruses cannot reproduce on their own
viruses are unable to grow or divide
viruses have no membranes of their own
viruses have no ribosomes for protein synthesis
all of these choices support this conclusion
all of these choices support this conclusion
A \_\_\_\_ is a kind of virus that can infect bacteria bacteriophage cyanobacteria retrovirus HIV
bacteriophage
What are viruses, viroids, and prions?
nonliving, infectious agents or pathogens that can cause disease in organisms
small sequences of nucleotides or amino acids that are devoid of their own cell membranes
substances that can cause disease only after entering a host cell and taking over the nuclear machinery
all of the above
all of the above
