biology test 12- viruses and bacteria

NOTE

*be able to label all parts of a bacteria*

NOTE

*be able to label all parts of a virus*

virulent phage

A phage that reproduces only by a lytic cycle is called a ________ ______

small, nuclei, cell walls

Archaebacteria and Eubacteria are equally _____, lack ______, and have ____ _____

decomposers

Bacteria are ____________ that help to recycle the essential chemical elements in living things

bacterium, viruses

Martinus Beijerinck used filtration experiments to prove that an agent smaller than a _________ was causing tobacco mosaic disease. He was the first to name these very small particles "________".

pili

____ are shorter and thinner than flagella

cocci, bacilli, spirilla

_____ are spherical _______ are rod-shaped ________ are spiral shaped or curved

oxygen, anaerobic

_______ is poisonous to methanogens; they must live in __________ environments such as deep fresh water, marine mud, swamp mud, and sewage

symbiosis

a close and permanent association between organisms of different species

pathogen

a disease-causing agent

autotrophs

a few bacteria are __________, meaning they have the ability to make their own food

true nucleus, membrane-bound organelles

a prokaryotic cell does not have a ____ ________ or ________-_____ __________.

dormant, death

a retrovirus may remain _______ for some length of time, but will eventually become active, causing the host cell to make new viruses and causing the _____ of the host cell

plasmid DNA

a small circular piece of DNA that is separate from the chromosome; generally one gene

binary fission

a type of asexual reproduction where one cell undergoes cell division to form two identical cells

conjugation

a type of bacterial reproduction where a hollow bridge forms between two bacterial cells

genetic material

a viral infection begins when the _______ _______ (DNA or RNA) makes its way into a host cell

living cell, ceases

a virus is only active when it's inside a ______ ____; when removed, it _______ all activities but retains its ability to infect the cell

vaccine

a weakened or killed form of the pathogen that stimulates the body's immune system to produce antibodies

binary fission, increase

after conjugation, cells go back to _______ ______ and ________ in number

carbon, nitrogen, essenial elements

all living things depend upon a constant supply of ______, ________, and other ________ ________; these ^^ must be recycled when an organism dies.

parasites, host

all viruses are _________ and require a ____

inside, thick wall

an endospore is formed _______ of a cell; the contents of the cytoplasm draw up together and a ______ ____ is formed around it

virus

an infectious particle that is nonliving

animal proteins

animals eat the plants, and convert the plant proteins into ______ _______

bacteria

are antibiotics affective against bacteria or viruses?

rapid cell division, metabolic diversity

bacteria are successful because of their _____ ____ ________ (reproduction) and their great _________ ________

foods, beverages

bacteria are used to produce a variety of _____ and _________

large

bacteria are very ______ in comparison to a virus

living world

bacteria are vital to maintaining the ______ ______

20 minutes, forms of life

bacteria can double their numbers every __ _______ and live in environments that support no other ____ __ ____

cellular respiration, fermentation

bacteria release energy through the processes of __________ __________ or ___________ or both

separate domains

biologists now recognize that there are such great differences between two distinct groups of prokaryotes that they should be placed into __________ ________

adhere, substrate

capsules enable prokaryotes to _____ to their ___________ or to other individuals in the colony

antibiotics

compounds that kill bacteria

viroids

consist of small, circular molecules of RNA, but they have no protein coat; tiny molecules of naked circular RNA

prions

disease-causing particles that do not contain DNA or RNA

dryness, heat, cold, dormant

endospores can survive extreme ________, ____, or ____; they can remain _______ for months or years while waiting for favorable growth conditions to return

"true" bacteria

eubacteria are the "____" _______

environmental conditions

eventually, certain _____________ __________ (chemicals, radiation) may trigger the switchover from the lysogenic cycle to the lytic cycle

salt-loving

halophiles are ____-_______ bacteria; they live in environments that have very high ^^ concentrations, such as the Great Salt Lake and the Dead Sea

The leading hypothesis is that a prion is a misfolded form of a protein normally present in brain cells. When a prion enters a cell that contains the normal form of the protein, the prion converts the normal protein to the prion version.

how can a protein, which cannot replicate itself, be a pathogen?

he was able to isolate crystals in a virus sample; living organisms don't crystallize, so therefore viruses aren't alive

how did Stanley infer that viruses aren't alive?

they convert hydrogen gas and carbon dioxide into methane gas

how do methanogens get energy?

by getting the cell to produce viral parts instead of cell parts

how do viruses reproduce in living cells?

incredible rates

if conditions are favorable for growth, bacteria can grow and divide at ___________ ______

enters, copies, burst

in a lytic infection, a virus ______ a cell, makes _______ of itself, and causes the cell to _____

nitrogen fixation

in a process called ________ _________, bacteria are able to convert nitrogen gas into nitrates, a form that plants can use

capsule, polysaccharide

in bacteria, a ______ may be present outside of the cell wall; it is composed of a gluey ____________

double, DNA

in binary fission, the bacterium grows to nearly _______ its size, then replicates its ___ and divides in half

genes

in conjugation, ______ move from one cell to the other through the tube

numbers, genetic diversity

in conjugation, there is no increase in gene ________, but they have redistributed the genetic information; the transfer of genetic information increases _______ _________ in future populations

-the eventual exhausting of food supply -being poisoned by their own metabolic waste -competition from other microbes -being consumed by other organisms

in reality, prokaryotic reproduction is limited by :

indefinitely

in the lysogenic cycle of viral reproduction, the host cell makes copies of the viral genetic material __________

host cell

in the lysogenic cycle, the virus incorporates its DNA into the DNA of the ____ ____; the viral DNA is then replicated along with the host cell's own DNA

parasites

live in or on other organisms and cause them harm

-they can reproduce but only inside a living cell -they can mutate or change -they have DNA or RNA; their genome may consist of only 4 genes, or up to 100 genes

living characteristics of viruses:

20 minutes, 3 days

many bacteria can divide every __ _______ (under ideal conditions); if reproduction continued unchecked at this rate, a single prokaryotic cell could give rise to a colony outweighing Earth in __ ____

cows, termites

methanogens also thrive in the digestive tracts of _____ and _______; ^^ can release 200 to 400 liters of methane gas per day.

heterotrophs

most bacteria are ___________, meaning they do not have the ability to make their own food

reproduction, slow

new drugs have been developed that interfere with _____________ of viruses, but only ____ the effect of the virus; they do not provide a cure

80, directly

nitrogen gas makes up about ___ percent of Earth's atmosphere, but plants and animals are not capable of using it ________

-they are non-cellular -they have no metabolism; they have no food or energy requirements -they can be crystallized and dehydrate and stored indefinitely; they come to "life" only when injected inside a living cell

non-living characteristics of viruses:

assembles

once a host cell makes copies of viral DNA and protein capsids, the host _______ the parts into viruses

viral genome

once a virus hijacks and reprograms a cell, the _____ _______ takes over the host cell and makes the host cell start producing viral parts

hijacks, reprograms

once a virus is inside a cell, it _______ and _________ it

protein capsids

once the viral genome takes over the host cell, the host cell will begin to make copies of the viral DNA and producing the ________ ________

facultative anaerobes

organisms that can survive with or without oxygen; do not require oxygen, but neither are they killed by its presence; allows these organisms to live just about anywhere

obligate aerobes

organisms that require a constant supply of oxygen in order to live

recognize

our immune system launches a response to the harmless form (vaccine), thereby learning to __________ it the next time that we are exposed to it

photoautotrophs

photosynthetic organisms that use light energy from the sun to convert carbon dioxide and water into the organic molecule glucose and oxygen

-a food source -the surface of a liquid -another bacteria during reproduction

pili serve to attach bacteria to :

nitrogen, proteins

plants and animals must have ________ to build amino acids; amino acids are needed to build ________

plant proteins

plants take up nitrates created by nitrogen fixation through their roots and use them to build _____ _______

protein

prions are tiny bits of _______

mad cow disease

prions cause degenerative brain diseases such as:

-shape -the materials composing of the cell wall -the way they move -the way they obtain energy

prokaryotes are identified by several characteristics :

biosphere, eukaryotes

prokaryotes dominate the _________; their collective biomass outweighs all __________ combined by at least 10 fold

immunity

rapid response of the immune system because of vaccines

cancer

retroviruses are responsible for types of ______

RNA, DNA

retroviruses have ___ as their genetic information rather than ___

reverse transcriptase, chromosome

retroviruses have an enzyme called _______ ___________, which transcribes their RNA template into DNA; the newly made DNA then enters the cell's nucleus and integrates into the DNA of a __________

dead organic matter, decomposers

saprophytes live on _____ ______ ______; they are very important as __________

highly specific

since viruses must bind precisely to proteins on the cell surface, they are _____ _______ to the cells they infect

motile

some bacteria are ______ and other do not move at all

harmful, benign

some bacteria are ________ and cause diseases, but most bacteria are _______ or beneficial; a relatively small number of species cause disease

pathogenic

some bacteria are __________ (cause diseases)

oil

some bacteria can digest ___ and are helpful in cleaning up oil spills

obligate anaerobes

some bacteria don't require oxygen and are killed in its presence; these organisms must live in the absence of oxygen

flagella, slime

some bacteria move by means of _________, which are whip-like structures used for movement; some lash or whip forward; others slide over a layer of _____ they secrete

dehydration, attacks

some capsules protect against ___________; some capsules shield pathogenic bacteria from _________ by their host's immune system

mutualism

symbiosis that is beneficial to both species

parasitism

symbiosis where one species benefits and the other is harmed

commensalism

symbiosis where one species benefits from the association while the other is neither harmed nor helped

peptidoglycans, membrane lipids

the Archaebacteria lack the _____________ found in the eubacteria; they also have different _______ ______

eukaryotes, eubacteria

the DNA sequences of key archaeological genes in Archaebacteria are more like those of _________ than those of ________

cytoplasm

the ________ of bacteria does not contain any membrane bound organelles

harsh environments

the archaebacteria live in extremely _____ _____________, such as : swamps, salt lakes, and hot springs

prokaryotes

the bacteria are ___________

vaccines

the battle against viral diseases lies in the use of _________

-suitable temperature : 80-100°F -moisture -suitable food source -darkness -space to grow

the best environment for growth of bacteria has :

receptors

the capsid has a particular shape that must match __________ on the surface of a host cell; when the virus attaches to these ^^, the cell is "tricked" into letting the virus inside

proteins

the capsid is made of _______ that enable the virus to enter the host cell

one single, circular, continuous

the chromosome of bacteria consists of ___ ______, ________, _________ molecule of DNA

ribosomes

the cytoplasm is filled with many ___________

peptidoglycan

the eubacteria have a cell wall that contains a polysaccharide called _____________

saprophytes, parasites

the heterotrophic bacteria are further divided into ____________ and _________

infectious agent, disease

the important lesson we have learned from viroids is that a molecule can be an __________ _____ and cause _______

host

the living organism a parasite lives on

generations

the prophage in a lysogenic infection may remain part of the host for many __________ before becoming active

capsid

the protein coat that surrounds the DNA or RNA on a virus

virology

the study of viruses

prophage

the viral DNA embedded into the host cell's DNA

hundreds of thousands

the viral reproductive cycle ends with the exit of ________ __ _________ of viruses from the infected host cell

archaic, ancient, millions

the word "archaea" means "_______ or _______" since many of the known species of archaea live in extreme environments thought to resemble the harsh environments present ________ of years ago

poison

the word virus comes from the Latin word meaning "_______"

environment

there is great variety in the organisms that belong to Eubacteria; these bacteria are found in every ____________ on Earth

hydrothermal vents

thermoacidophiles are often found around ____________ _____ (black smokers) that leak very hot, dark-colored, acidic water

acidic, high

thermoacidophiles live in very ______ environments that have very ___ temperatures, such as the hot springs in Yellowstone National Park (these organisms can thrive in temperatures of 110°C and at a pH of less than 2)

false; does not kill right away because it remains inactive for a long period time

true/false: lysogenic viruses kill the cell right away because they may remain active for some period of time

false; plant viruses only infect plant cells, and animal viruses only infect animal cells

true/false: plant viruses infect animal cells, and animal viruses infect plant cells

true

true/false: prokaryotes can easily survive without eukaryotes, but eukaryotes are totally dependent on prokaryotes

true

true/false: there is little that can be done to cure a viral infection

true

true/false: viral reproduction often destroys the host cell

false; they aren't

true/false: viruses are affected by antibiotics

true

true/false: viruses can reproduce, but only inside a living cell

Eubacteria

under a microscope, Archaebacteria look very similar to the __________

Monera

until recently, all prokaryotes were placed in a single kingdom called the ______ kingdom

chemoautotrophs

use the energy from inorganic reactions as a source of energy to build molecules of glucose

simplicity, size

viroids are known for their extreme _________ and small ____; they are much smaller than a virus

plants, animals

viroids have only been identified in ______, but they are suspected of causing some diseases in _______ for which no pathogen has ever been isolated

non-cellular

viruses are ___-________, meaning they are not made of cells and have no cell parts

small, electron microscope

viruses are extremely _______; most can only be seen with an ________ __________

crystallized

viruses may be ____________ and stored indefinitely, but even after long periods of time, they retain their ability to infect a living cell

tissue specific

viruses of eukaryotes are usually ______ ________

size, structure

viruses vary widely in terms of ____ and _________

Staphylococcus Streptococcus

what are 2 types of pathogenic diseases?

sour cream, yogurt, and cheese

what are examples of bacteria in foods and beverages?

-colds -hepatitis -flu -west nile virus -chicken pox -AIDS

what are some common viral diseases?

DNA or RNA surrounded by a protein

what are the 2 parts viruses consist of?

-other bacteria release toxins or poisons in the body of the host -some bacteria damage the cells and tissues by breaking down the cells for food

what are the 2 ways bacteria produce diseases?

-methanogens -halogens -thermoacidophiles

what are the 3 archaea groups?

AIDS

what is an example of a retrovirus?

d = Archaea k = Archaebacteria

what is the domain and kingdom of Archaea?

d = Bacteria k = Eubacteria

what is the domain and kingdom of Bacteria?

Release: -the cell swells, bursts, and releases 100's of new viruses

what is the fifth step of the lytic cycle? explain it.

Attachment: -tail fibers are used to attach to receptor sites on the surface of the host cell

what is the first step of the lytic cycle? explain it.

Assembly: -the viral DNA or RNA is assembled inside the protein coat

what is the fourth step of the lytic cycle? explain it.

lytic- viral DNA completely takes over host cell DNA lysogenic- viral DNA shares cell with host DNA, so that each new reproduced cell will be part viral DNA and part host cell DNA (stress event will eventually trigger viral DNA)

what is the main difference between the lytic cycle and the lysogenic cycle?

Entry: -phage DNA is injected; empty capsid remains outside; host cell DNA is destroyed

what is the second step of the lytic cycle? explain it.

Synthesis: -the host cell is directed to produce viral genomes and protein capsids

what is the third step of the lytic cycle? explain it.

they enter living cells and use the machinery of the cell to produce more viruses

what thing do all viruses have in common?

decompose, nitrogen

when an organism dies, bacteria ___________ the organism, returning ________ to the ecosystem to be used again

simpler materials

when an organism dies, it is attacked by bacteria and broken down into _______ __________

endospores

when conditions for growth become unfavorable, many bacteria form structures called ____________

much faster

when we are exposed to the "real" pathogen (after a vaccine), our immune system can respond ____ _______ since it has already learned to recognize the pathogen

lytic cycle and lysogenic cycle

which two processes may occur once virus is inside a host cell?

Wendell Stanley

who inferred that viruses aren't alive?

Martinus Beijerinck

who is considered the founder of virology?

anything that will kill the virus will also kill the host (ex.- poison)

why aren't viruses affected by antibiotics?