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