diversity of living things CHAPTER 2 Flashcards
what kind of viruses keep changing ?
retroviruses keep changing, the outer coat (lock) changes because they don’t copy well
another name for RNA virus ?
retrovirus
what is a memory b plate and where are memory B cells found
memory b cells are in breast milk
your body makes a memory b plate when you get sick
the mother passes on the memory b cells, the antibody for viruses
memory b cells are the template for antibodies
new memory b cells are made when you get sick
an older person has more memory b cells than a young person
you have a copy of memory b cells forever
what do AIDS attack ?
helper t 4 cells
diseases such as pneumonia will kill you if all your helper t 4 cells are killed
which RNA virus was really bad in the 50s
polio
kids were bedridden and crippled; kids were in wheelchairs
no one was allowed to go outside
a miracle was the polio vaccine; people lined up all over America to get vaccinated
still around in some countries (India)
what is the chance of dying if you have rabies ?
if you don’t get medication, you will 100% die
almost always fatal, lethal
transferred by the spit of rapid animals
symptoms can submerge in 5 days or even a year
who is the master of mutation ? why ?
the common cold
the lock must always be the same to make a key
there is no vaccination
how is flu vaccination made ?
the new flu usually comes from Asia (density of humans and animals)
there is a lot of guessing involved in making the vaccine
people are sent to Asia to take note of what kind of flu most people have
vaccines require thousands and thousands of chicken eggs
vaccins are injected into the chicken eggs (eggs are cells)
they hope to make a vaccine that will be like a master key (fits every lock)
flu is one of a few rare viruses that has ….
its genome in separate segments (eight)
this increases the potential for recombinants to form (by interchange of gene segments if two different viruses infect the same cell) and may contribute to the rapid development of new flu strains in nature
what is the worst case scenario for viruses ?
mixed virus
avian and human strains recombining in pigs in the far east may permit virulent human strains to evolve
what does virus mean in latin
poison
when was the Spanish flu the deadliest in American history ?
October, 1918
how many americans died in one month ?
195 000
how many people worldwide died from the Spanish flu ?
30-50 million
more people died from ___ than ___
the Spanish flu then from WWI
why is it called the Spanish flu ?
because spain was the only country printing news about it since spain wasn’t involved in the war
where did the Spanish flu start
in the U.S.
fort Riley, Kansas
when did the spanish flu mutate ?
before it was brought to Europe, by the time it was brought back it was worse
what happens to your skin and lungs when you have the Spanish flu ?
your skin will rot and turn black
your lungs fill with fluid, you suffocate to death
pneumonia will kill you
why is a virus not considered a living thing
they don’t display the essential characteristics of living
they don’t breathe or move around
are not cellular, so they don’t have a cytoplasm, membrane-bound organelles, or cell membranes
do not reproduce
“the ultimate parasite”
virus
how big is a virus ?
10 nm to 275 nm
can antibiotics be used to treat bacterial infections and viruses ?
only for bacteria but not viruses
what are viruses composed of ?
a molecule of nucleic acid (DNA or RNA) surrounded by a protein coat (capsid)
what is another name for a protein coat ?
capsid
what does the protein coat do ?
protects the nucleic acid and determines what type of cell a virus can infect (helps the virus attach itself to specific receptors on the host cell- “lock and key”
RNA viruses have a special enzyme called
reverse transcriptase (turns RNA into DNA)
how do viruses manipulate cells into producing new viruses ?
they force the living cell into producing new viruses by incorporating their viral genes into the host cell’s DNA
once inserted, the viral DNA is called a provirus and is replicated along with the host’s DNA
which type of virus is usually more lethal ? why ?
RNA viruses are more lethal than DNA viruses
they have a latency period, so they remain hidden before the body’s immune system is triggered
during this time, many viruses are being produced in the host cells, using the host’s raw materials and machinery
RNA viruses comprise ___ % of all viruses
70 and have a higher mutation rate
RNA virus analogy
guerilla warfare
hide in the forest, stockpiling weapons and troops
surprise attack during the night
DNA virus analogy
marching british redcoats
drums and flags in an open field in daylight
list some RNA viruses
HIV/Aids polio rabies, common cold influenza measles mumps sars
list some DNA viruses
mono cold sores chicken pox small pox shingles warts herpes
smallpox is the exception
when was it declared extinct ?
all the natives were killed with smallpox
north America was conquered with disease
smallpox was declared extinct in 1979
the last cause died in 1977
which virus is sars-like ?
corona virus traced back to the middle-east contagious, passed from human to human from bats spread in Mecca- a monument that holds millions
what are the non viral disease-causing agents ?
prions
first discovered in the 80s by Stanley Pruisner
prions are proteins that are normally found in the body
only disease causing agents that lack RNA or DNA
they change their molecular shape to become harmful
normally harmless
cause brain disease, mad cow disease/ CJD
millions of cows were slaughtered
Jenny McCarthy blamed her sons autisms on
vaccines
phony article stated that mercury was used in vaccines to store it and was causing the autism
the author made up all the data
she started an anti-vaccine campaign
what are viral vectors ?
viruses enter host cells and direct the activity of the host cell’s DNA, they can be useful tools for genetic engineers
for example, if researchers want to make a copy of a gene, they first insert the gene into the genetic material of a virus
the virus then enters the host cell and directs the cell to make multiple copies of the new virus
each new virus in each new cell contains the added gene that the researchers wanted to copy
are bacteria and archaea similar ?
they are more different from each other than an apple tree is from a blue whale
what metabolism is unique in archaea ?
methanogenesis = a biological process that produces methane as a by-product
which is an anaerobic process (without oxygen)
that occurs in environments that lack oxygen
where is methanogenesis found ?
found often in the gut/intestines of cattle
what animal is one of the top producers of methane gas ?
cows
corn is fed to cows to make them taste better
corn is hard to digest
methane-producing archaea live in the digestive tracts of animals
can archaea photosynthesize ?
no, but some bacteria can
can archaea and bacteria survive in extreme conditions ?
archaea are extremophiles so yes
bacteria cannot
what are the 3 types of extremophiles ?
- thermophile (heat-lover)
- acidophile (acid-lover)
- halophile (salt-lover)
where are thermophiles found ?
hot springs
deep sea vents
where are acidophiles found ?
volcanic crater lakes
mine drainage lakes
where are halophiles found ?
salt lakes and inland seas
when was archaea discovered ?
in the 70s
archaea are riddled with _____
viruses
what does LUCA stand for ?
last universal common ancestor
they are bacteria, archaea and eucaryota
all domains share:
ribosomes
DNA/RNA
membrane
cytoplasm
what is bacteria made of ?
has a cell wall
made of peptidoglycan (which antibiotics go after)
what are endospores ?
a dormant bacterial cell able to survive for long periods during extreme conditions
- hard walled structures
- resistant to high temperatures, drying out, freezing, radiation and toxic chemicals
- endospores have not been found in archaea
- bacteria form endospores in life threatening conditions
3 main bacteria shapes
- cocci- spherical
- bacilli- rod shaped
- spirilli- spiral shaped
what are the two methods of reproducing in bacteria ?
- binary fission (asexual)
2. conjugation (sexual)
what is binary fission ?
the most common form of reproduction
DNA molecule attaches itself to a cell membrane
the DNA replicates
the cell membrane grows
the cell membrane indents
then the cell divides to form two new cells
what is conjugation ?
a donor cell and a recipient cell
DNA of donor chromosome transfers to recipient cell (passing on resistance)
what is a miracle that bacteria can perform ?
bacteria can mutate and start eating weird food
ex. nylon eating bacteria
bacteria can adapt
can mutate to eat chemicals that were meant to kill them
bacteria is bred to clean oil spills
why must ships be super clean before launching into space ?
viruses can mutate from the radiation in space
an errant microbe could contaminate the planet
deadly viruses can be brought back to earth
the toughest passengers are bacillus which have a protective coat
what is Bacillus odyssei ?
a bacterium that evolved to live in the spare environment of a clean room
how was antibiotic resistance created ?
overuse of antibiotics (they’re prescribed when we don’t need them)
new antibiotics haven’t been made since the 70s
animals are fed antibiotics and sprayed onto crops to speed up the growth process
when we eat meat, we consume the antibiotics
people don’t finish the full dose of antibiotics
would pharmaceutical companies profit more from new diabetic/obesity pills or from antibiotics?
from obesity/diet pills because they are consumed daily
antibiotics are consumed for 2 weeks
what happened with cholera ?
1866
drinking water
epidemic, city of London, Europe
still prevalent in some places of the world
John Snow, first epidemiologist stopped the epidemic
took the handle of the Broad St. pump
black death: how many people died
what is it called
when
bubonic plague
Yersinia pestis
killed between 1/3-1/2 of people in Europe in 5 years (about 25-40 million)
started in the 1330s
how many modern strands are there of the black death
17 modern strands, they’re 97% different
where did the black plague originate from ?
the Gobi desert, China
the black sea
natural host is rodents (rats)
fleas live off the blood of rodents and humans
dead rats are a bad sign; fleas will need to find a new host
people in Europe at that time were malnourished, had poor sanitation, with rats and human feces, filthy conditions
symptoms of the black plague
painful swelling to lymphnodes
bubos “boo-boo”= grapefruit sized swelling under arms and groins that split open and black puss oozes out
your skin will turn black and rot, revolting smell
you would die within a week
people would die alone because they were thought to be evil
what is the world’s first pandemic ?
the black plague
flesh eating disease
flesh eating disease
streptococcus
can happen in a short period of time (24 hours, 2 days)
skin rots, black hole on your body
immune if you have the antibodies from surviving strep throat
____ can be a problem for patients taking antibiotics, which disrupts normal intestinal flora
clostridium difficile
for 5-10% of the population, clostridium difficile is a normal part of their intestinal makeup and causes no harm
clostridium difficile cells and spores are ingested. the cells die quickly but
the spores can survive in stomach acid
the spores germinate upon exposure to bile acids
the bacteria can produce toxins which bind to receptors in the lining of colon
symptoms of clostridium difficile
diarrhea and inflammation
some cases, vomiting, dehydration and death
the hardest-to-control pathogen of about a dozen deadly healthcare associated infections
c diff.
do hand gels work on c. diff ?
no, but hand soaps do
what does TB stand for
tuberculosis
1 killer in history is
tuberculosis
killed over 500 million
where is TB common in ?
very common in poor countries
often found in homeless people in N. America
how does TB attack lungs ?
airborne TB bacteria are inhaled into the lungs
macrophages, a kind of defensive cell, attack the particles, killing or surrounding them
other immune cells surround particles in hard lumps called tubercles, making bacilli harmless
if the body’s immune system weakens, bacilli can escape
they multiply and penetrate blood vessels, spreading disease throughout the body
