Viruses, Kingdom Archaea and Kingdom Bacteria

Question 1

What does “virus” mean?

Answer 1

It is Latin for poison

Question 2

What is special about RNA viruses?

Answer 2

they have a special enzyme called reverse transcriptase –> must turn the RNA into DNA
they are also more lethal than DNA viruses because they remain “hidden” for a long time (latency period) before the body’s immune system is triggered

Question 3

Can antibiotics get rid of viruses?

Answer 3

No, antibiotics only kill bacteria. however vaccines can prevent some viral infections.

Question 4

What is an analogy for RNA viruses?

Answer 4

They are like guerrilla warfare–>hide in the forest, stockpiling weapons and troops-surprise attack during the nigh
EXAMPLE: HIV/Aids, Polio, Rabies, Common Cold, Influenza, Measles, Mumps, SARS

Question 5

What is an analogy for DNA viruses?

Answer 5

Marching British Redcoats-drums and flags in an open field in daylight
EXAMPLE: mono, cold sores, chicken pox, smallpox, shingles, warts, herpes

Question 6

What is significant about small pox?

Answer 6

~wiped out the natives by the millions, allowing us to concour North America
~Worse than RNA viruses
~it was officially declared extinct in 1979
~the last deaths from it were in 1977

Question 7

What is the lytic cycle?

Answer 7

1) Attachment: the virus attaches itself to the cell
2) Entry: then the virus injects its nucleic acid into the cell
3) Replication: the hosts metabolism replicates the viral DNA or RNA
4) Assembly: New virus particles are assembled
5) Lysis and Release: the host cell breaks open and releases new virus particles

Question 8

What is the largest cell?

Answer 8

An ostrich cell

Question 9

What happens when a mother breast feeds her baby?

Answer 9

she passes on her antibodies to the baby (called Memory B cells) these antibodies last 6 months then the baby has to start making their own

Question 10

What are Memory B cells?

Answer 10

They are the template of anitbodies

Question 11

What do Helper T4 cells do?

Answer 11

They help Memory B cells form antibodies and increase the number of killer TB cells

Question 12

What does the AIDS virus do to the Helper T4 cells?

Answer 12

the enter the new Helper T4 cells and destroy them. When they have all been destroyed then other diseases can invade the body and cause death (ex. pneumonia)

Question 13

Explain: Rabies

Answer 13

~if you get bit and do not do anything about it you will die
~transmitted through saliva of a rabid animal
~paralysis in mouth; strange or unusual behaviour
~5 days to a few years before symptoms show
~you get paralyzed then go into a come, then death

Question 14

Explain: Flu (influenza)

Answer 14

~many flus originate in Asia, where it is densely populated and close to wildlife (cross contamination)
~flu is one of the rare few that has its genome in separate segments (eight). This increases the potential for recombiants to form (by interchange of gene segments if different viruses infect the same cell) and may contribute to the rapid development of a new flu in nature
~Avian and human strains recombining in pigs in the far East may permit virulent human traits to evolve
i.e. bird, pig, and human

Question 15

Explain: The Spanish Flu

Answer 15

~deadliest month was October in the American’s history
~called in 13 million to cramped buildings
~200 000 people in Philadelphia
~195 000+ Americans died in a month
~Early November: new cases decreased
~30 million dead all around the world (30-50) in the year
~spread during ww1
~more people died from the flu than the world
~originated in the US at Fort Riley in Kansas
~people who had it and survived still have the antibodies
~these antibodies have mutated and now bind tighter to disease cells making them more potent (bind together than any other anti-bodies)
~remarkable durability of the human immune system

Question 16

Explain: Corona Virus

Answer 16

~SARS-like, similar to the common cold
~originated in the middle east 
~from bats 
~can be passed from human-to-human 
~nervous for the large group of people going to the Middle East for Mecca

Question 17

What is a prion?

Answer 17

An infectious particle that causes damage to nerve cells in the brain, and that appears to consist mostly or entirely of a single protein
~first discovered in 1980
~Prions are proteins found normally in the body
~They are the only known disease-causing agents that lack RNA or DNA
~they normally are harmless, if it changes molecular shape, it will become harmful
~called Mad Cow (when found in cows), scrapie’s (found in sheep), CJD (humans)

Question 18

What is one metabolism that appears to be unique to Archaea?

Answer 18

Methanogenesis: it is a biological (or chemical) process that produces methane (CH4) as a by-product
~it is an anaerobic process that occurs in environments that lack oxygen, and it is often one of the final stages of decomposition
~methane-producing archaea live in the digestive tracts of animals such as cattle, making these animals a source of methane gas

Question 19

Can Archaea photosynthesize?

Answer 19

No, that is the key difference between it and Bacteria

Question 20

What is an extremophile?

Answer 20

An organism that lives in habitats characterized by extreme conditions

Question 21

What are the three main types of extremophiles?

Answer 21

1) thermophile–“heat lovers”–>found in deep sea vents and Hot Springs
2) Acidophile–“acid lover”–>found in volcanic crater lakes and mine drainage lakes
3) Halophile–“salt-lover” –>found in Salt Lakes and Inland seas

Question 22

What are some facts on Archaea?

Answer 22

~they discovered Archaea (meaning “Ancient Ones”) in the 1970s
~Archaeas believed to be older than bacteria, they are the oldest form of life
~scientists hypothesize that viruses existed before Archaea
~many new, unknown viruses are found within Archaea
~Archaea was discovered to be riddled with viruses
~LUCA–Last Universal Common Ancestor

Question 23

What is endospore?

Answer 23

A dormant bacterial cell able to survive for long periods during extreme conditions
~endospores are resistant to high temperatures, drying out, freezing, radiation and toxic chemicals. When suitable conditions return, the endospore germinates back into an active bacterium. So far, endospores have not been found in archaea
~in life-threatening conditions, certain species of bacteria form endospores that enable them to remain dormant (in active) for periods of time that range from weeks to thousands of years

Question 24

Why is bacteria antibiotic resistant?

Answer 24

1) overuse of antibiotics
2) stopped creating new antibiotics (last one made in the 70s)
3) feed animals/ spray crops with antibiotics to increase growth by 3-5%
4) not finishing prescribed antibiotics

Question 25

What is necrotising fascitis?

Answer 25

~strep bacteria type
~can happen in a short period of time
~rots flesh, turns it black
~if youve had strep throat, you already have the antibodies

Question 26

Explain how TB Attacks lungs

Answer 26

1. Airborne TB bacteria are inhaled into the lungs’ small tubes
2. macrophages, a kind of defensive cell, attack the particles, killing or surrounding them
3. other immune cells surround particles in hard lumps called tubercles, making bacilli harmless
4. if the bodys immune system weakens, bacilli can escape from the tubercle
5. weakened immune system can’t neutralize the bacilli. They multiply and penetrate blood vessels, spreading disease throughout the body

• *TB killed over 500 million–>#1 killer in history
• *often found in homeless people in north america
• *very common in poor countries
• *die from TB is you’ve got AIDS (usually)

Question 27

What is Clostridium Difficile

Answer 27

outbreak in hoseph brant hospital; hundreds died in Quebec
~it is a normal part of their intestinal makeup and causes no harm. but it can be a problem for patients taking antibiotics, which disrupts normal intestinal flora, allowing C.difficile to grow
1. the spores can survive in the stomach
2. they germinate upon exposure to bile acids
3. toxins can cause vomiting, dehydration and death

fecal transplant=92% success rate

Question 28

What is the scientific name for the black death?

Answer 28

Versina pestis