microbes and fungi Flashcards
a biological particle made of nucleic acid surrounded by a protein capsid
virus
the protein coat of a virus
capsid
a virus that infects bacteria
bacteriophage
How are viruses similar to cells?
- made of some of the same chemicals 2. can reproduce (but need a host cell) 3. can evolve over time
How are viruses different from cells?
- no cell parts 2. no metabolism - don’t need energy 3. no growth or development 4. no response to environment 5. must have a host cell to reproduce
Which evolved first, viruses or bacteria? How do you know?
bacteria - because viruses couldn’t have reproduced without a host cell
Describe a lytic infection.
The virus takes over the cell right away, forces the cell to make more viruses, and then splits open the cell allowing the virus to spread to more cells.
Describe a lysogenic infection.
The virus quietly injects DNA into the cell. The virus prophage is copied every time the cell reproduces. Then some environmental trigger causes the cell to become lytic.
the splitting open of a cell
lysis
viral DNA that has been inserted into host DNA
prophage
a virus that uses RNA as its genetic code
retrovirus
a dead or weakened germ that helps prepare the immune system to fight off the virus
vaccine
Who developed the first vaccine and from what?
Edward Jenner - cowpox virus protected from smallpox
Why don’t antibiotics work on viruses?
viruses aren’t living - can’t kill something that isn’t alive
Other than proteins and nucleic acids, what chemical were viruses made up of?
lipids
What is the purpose of the proteins in the viral capsid?
bind the virus to its host
What contains the instructions for making new copies of a virus?
coded for in the viral DNA or RNA
Give 3 examples of viral diseases.
AIDS/HIV, measles, polio, smallpox, ebola, herpes, cold, influenza, chicken pox, hepatitis, West Nile, HPV
How do viruses cause diseases?
destroy cells and affect cell processes
cells without a nucleus and without membrane-bound cell organelles like mitochondria or chloroplasts
prokaryotes
What are the only cells that are prokaryotes?
bacteria
Name and describe the two major groups of bacteria.
- Archaea - bacteria with genes and metabolic activities more similar to eukaryotes, no peptidoglycan in cell walls 2. Eubacteria - common bacteria with peptidoglycan cell walls
long, whip-like structure used by bacteria to move
flagella
short hair-like structures used by bacteria to anchor to other surfaces
pili (pilus)
What is the shape of bacterial DNA?
circular
extra circular pieces of bacterial DNA
plasmids
Give some examples of the harsh environments bacteria are found in.
hot springs, Great Salt Lake, Dead Sea, hydrothermal vents
thermoacidophiles
live in hot acidic environments
halophiles
live in salty environments
methanogens
generate methane, live anaerobically in mud flats and swamps
the DNA region in a bacterial cell
nucleoid
the chemical polymer made of sugars and amino acids that is found in the cell walls of many bacteria
peptidoglycan
rod-shaped bacteria
bacilli (bacillus)
spherical bacteria
cocci (coccus)
helical bacteria
spirilla
clumps of bacteria
staphlo
chains or strips of bacteria
strepto
bacteria that must have oxygen to survive like Mycobacterium tuberculosis
obligate aerobes
bacteria that can NOT tolerate oxygen like Clostridium botulinum
obligate anaerobes
bacteria that can live with or without oxygen like E. coli
facultative anaerobes
asexual reproduction in bacteria - How fast can they divide?
binary fission - every 20 minutes
dormant state that allows bacteria to survive harsh conditions by surrounding and protecting their DNA
endospore
sexual process in bacteria involving exchanging DNA across a bridge of cytoplasm to allow diversity and survival
conjugation
mistakes in the DNA copy process that allows diversity
mutation
What two processes enable bacteria to produce food for themselves? How are these processes different?
- photosynthesis - uses light 2. chemosynthesis - uses chemicals in the absence of light like at volcanic hydrothermal vents
What important roles do bacteria serve in ecosystems?
- produce food and oxygen 2. decomposers - recycle nutrients in dead organisms 3. fix nitrogen
the process some bacteria use to make atmospheric oxygen suitable for plants to use as fertilizer
nitrogen fixation
Where is most nitrogen found? Where does nitrogen need to be for plants?
atmosphere - soil
What are the clumps of bacteria on some plants where nitrogen fixation occurs?
root nodules Rhizobium
What type of plants typically have root nodules? What type of bacteria are they?
legumes - peas, peanuts, soybeans, clover,
What is the advantage of alternating or rotating crops?
legumes replace nitrogen in the soil
What are some human uses of bacteria?
- tanning leather 2. producing food like yogurt 3. clean up oil spills 4. extract metals from rocks 5. clean up sewage 6. make medicines like insulin (drugs) 7. source of heat-stable enzymes
What are germs?
pathogens
What are some diseases caused by bacteria?
lyme disease tetanus tuberculosis strep throat tooth decay
How do bacteria make organisms sick?
destroy cells or make toxins
What is the number one way to prevent pathogenic infections?
washing hands with soap and warm water
chemicals that kill bacteria
disinfectants
What is the advantage of refrigeration and freezing?
slows bacterial growth
heating equipment to kill germs
sterilization
drugs that can kill bacterial infections
antibiotics
an organism that transmits a pathogen from one organism to another
vector
How can germs be spread from person to person?
- air (coughs and sneezes) 2. water 3. food 4. animals
How are bacteria and archaea different?
peptidoglycan isn’t in archaea
What type of prokaryote is E. coli?
bacteria
How are bacteria and archaea different?
- different carbohydrate in cell wall 2. different lipids in membranes 3. different genes (Archaea more like eukaryotes)
Name 3 common groups of archaea.
- thermoacidophiles 2. halophiles 3. methanogens
Where do we find photoautotrophs?
in light
organisms that break down dead organisms and wastes
decomposers
What two chemicals are produced during decomposition?
carbon dioxide and water
an unknown disease or a well-known disease that becomes more difficult to treat
emerging disease
Why are emerging diseases so dangerous?
- We have little to no resistance to them? 2. They are resistant to antibiotics 3. They jump from one type of organism to another.
What do we need to do to prevent the development of “superbugs” or “supergerms”
Use antibiotics only when necessary, and use them correctly.
Name the cell in the picture, and identify all the cell parts.
bacteria
- flagellum 2. pilus 3. nucleoid 4. plasma membrane 5. ribosomes 6. cell wall 7. capsule
Name the following image
bacteriophage
Name the organisms in the image 1-6.
- monococcus
- diplococcus
- streptococcus
- staphylococcus
- bacilli
- spirilla
What viral life cycle is shown in this image? How do you know?
lytic cycle - bursting open the cell
What viral life cycle is shown inthe image? How do you know?
lysogenic cycle - quietly copying the viral DNA (prophage)
What is happening in the image below? What is this process called?
Two bacteria are exchanging DNA through conjugation.
What is happening in the image below? What is the name of this process?
Bacteria are reproducing asexually by binary fission.
What is being shown in the image, and what is their purpose?
endospores help cells survive harsh conditions
What is shown in the image, and what is their purpose?
bacterial root nodules (Rhizobium bacteria) on the roots of a legume like alfalfa or clover
Why are protists considered the junk drawer kingdom?
What goes in the kingdom protista?
Why are the protists hard to classify?
What will happen to protists?
If an organism doesn’t fit into any other kingdom, it was placed in this group. Many organisms in this group are more related to organisms in other kingdoms than to eachother.
any eukaryote that is not a plant, animal, or fungus
Some protists have traits of more than one kingdom.
The protist classification will change.
What is meant when we say protists are eukaryotes?
Their cells have a nucleus and membrane-bound organelles.
Name and describe the theory about how eukaryotes evolved from prokaryotes.
theory of endosymbiosis - prokaryotes ate other prokaryotes but instead of being digested, it lived inside the other prokaryote and was helpful with its energy needs
Name two organelles that are evidence for endosymbiosis. Give 4 pieces of evidence.
mitochondria and chloroplast
- have double membranes as if a food vacuole was formed around them
- have their own DNA in a circular piece like bacterial DNA
- divide themselves as if they were separate living organisms
- they have ribosomes that resemble bacterial ribosomes
Name and describe the 4 main groups of protists based upon how they move, and give examples of each group.
- sarcodines - move by changing cell shape (pseudopods - false feet) - amoeba
- flagellates - move with a flagellum (long, tail-like structure) - euglena
- ciliates - move with cilia (short, hair-like structures) - paramecium
- passive movement - make spores that are carried by wind, water, and other organisms - Plasmodium (causes malaria)
false feet - cytoplasmic extensions that help amoebas and their relatives move
pseudopods
How is Plasmodium (protist that causes malaria) transmitted?
mosquitoes
How is Cryptosporidium (causes severe intestinal disease) transmitted?
contaminated drinking water
How do most protists reproduce?
asexually by cell division
a sexual process in some protists that allows for genetic diversity
conjugation
Name and describe the two types of nuclei in paramecia. Which one is exchanged during conjugation?
What happens to the macronucleus during conjugation?
macronucleus - larger, working nucleus that contains many copies of genes
micronucleus - smaller, reserve copy of thegenes
The micronucleus is exchanged during conjugation.
The macronucleus disintegrates.
when organisms switch back and forth between sexual and asexual phases to take advantage of the environment
alternation of generations
- reproduce asexually when conditions are good - to reproduce quickly
- reproduce sexually when conditions are poor - to get diversity
drifting, plant like organisms that start most aquatic food chains
drifting, animal-like organisms
phytoplankton
zooplankton
large, brown algae that form “forests” in the ocean
kelp
other than green algae, the algae that are most closely related to plants
red algae
What happened to the kelp forests when we killed the sea otters for their pelts?
The otters weren’t there to keep the populations of sea urchins in check. The urchins overpopulated and ate all the kelp. Many species were threatened because, without kelp forests, they wouldn’t have a place to live.
How do algae help coral?
red algae live mutualistically in the coral and help make calcium carbonate skeleton
Name 4 reasons protists are important to ecosystems.
- produce food and oxygen
- provide shelter and support coral reefs
- recycle wastes
- can cause diseases
the membrane covered structure in protists for storing their food until it is digested
food vacuole
What does the food vacuole fuse with to digest the food?
lysosome - sac of digestive enzymes
the mouth of a ciliate
the throat of a ciliate
where waste is released from a ciliate
mouth - oral groove
throat - gullet
waste release - anal pore
Where do slime molds live? What are their 2 stages?
damp, nutrient rich areas like forest floor
- amoebas (singular)
- plasmodium (multicellular)
How does the slime mold plasmodium and the water mold reproduce?
sporangia - spores
What do the Tryconympha protists that live in termite guts do for the termites?
digest cellulose (wood)
What vector carries the protist Plasmodium that causes malaria? Why don’t we have malaria in the United States?
How can beople control the spread of malaria?
Anopholes mosquito - too tropical
We can control the spread f malaria by controlling mosquitoes.
What is the vector for the parasitic protist Trypanosoma that carries African sleeping sickness and Chagas disease?
biting flies like the tse tse fly
Other than African sleeping sickness and malaria, name 3 other diseases caused by protists.
- amoebic dysentery
- giardiasis
- Chryptosporidium
How big are most protists?
unicellular
Name a multicellular protist.
kelp
What happens when a large amount of nutrients is added to water?
algal bloom - algae overproduce, use up all the oxygen, and make water go stagnant
Some algal blooms make toxins making it dangerous to do what?
eat fish or shellfish from the area, swim…
Why do phytoplankton live near the surface of water?
need light for photosynthesis
How are plankton important to some whales?
Baleen whales feed on plankton.
Name the protist in the image.
ciliate - paramecium
Name the protist in the image.
sarcodine - amoeba
Name the protist in the image.
flagellate - euglena
Name the protist in the image.
slime mold
the chemical that makes up the cell walls of fungi
chitin
the microscopic threads within fungi
hyphae
a mat of hyphae typically found below ground level or inside the bark of a decaying tree
mycelium
the reproductive structure of a fungus, makes spores
fruiting body
What do fungi have in common with animals?
chitin
heterotrophs
How do heterotrophic fungi get food differently from heterotrophic animals?
fungi - release digestive enzymes and absorb already digested food
animals - ingest food
a mutualistic relationship between an alga and a fungus
lichen
Why are lichen called pioneer organisms?
can live on bare rock and help produce soil for other organisms to move in
a mutualistic relationship between plant roots and fungi
mycorrhizae
How do mycorrhizae help plants survive and evolve?
help absorb water and minerals, enabled plants to move out on land
What is the most important role of fungi and bacteria in the environment?
decomposers - recycle dead organisms so the nutrients can be used by other organisms
What was the first antibiotic discovered? Why would fungi have chemicals that could kill bacteria?
penicillin - fungi and bacteria compete for food so a fungus that could kill bacteria have an advantage
Identify the organisms causing each of the following:
- athlete’s foot and ringworm
- strep throat, staph infection
- cold, flu, polio, mumps, measles, chicken pox
- amoebic dysentery, African sleeping sickness, giardiasis
- fungus
- bacteria
- viruses
- protists
