Contemporary Issues in Biology TCU
(Hale)
Plague - ANSBroke out in the 1300s and killed 75 million people by the early 19th century. Fleas
were spreading the plague. Modern antibiotics are effective against plague, but if an infected
person is to treated promptly, the disease is likely to cause illness or death.
Fleas spread plague by? - ANSfeeding on blood of mammals like rats, spreading the bacteria
that causes plague.
Malaria - ANSOne of the most deadly diseases in human history. Today it sickens 219,000,000
a year and kills 600,000 people a year, mostly children.
Malaria caused by? - ANSProtozoan (a single celled organism) that infects humans and
destroys red blood cells.
symptoms of malaria - ANSShivering, pain, fever and sometimes death is caused when the red
blood cells burst, releasing a new generation of malarial parasites. When young children are
infected they can have permanent brain damage and death
Historic Effects of Defeat Malaria - ANSPrevention of disease w/ drugs like Chloroquine to kill
malarial parasites.
Control Mosquitos by? - ANSDraining wetlands where mosquitoes breed and using pesticides
like DDT to kill mosquitos
Chloroquine - ANSis a medication to treat or prevent malaria.
How does Chloroquine work? - ANSby interfering w/ the growth of parasites in the red blood
cells of the human body
Malaria is usually spread by? - ANSGetting bitten by a mosquito caring the disease
Resistance to Chloroquine - ANSMalaria strains of plasmodia have become resistant to
chloroquine. Individual plasmodia (the single celled organism that causes malaria) have genetic
mutations that confer resistance. These resistant plasmodium survive and reproduce while
individuals w/o the mutations die off.
DDT - ANSSpray to kill Mosquitoes, but was banned in 1972 in USA
,Pyrethrin Insecticides - ANSwere developed from a natural substance in chrysanthemums.
Thought to be non-toxic to humans but little research in this area has been done. Used for a
decade(s) long campaign against malaria, responsible for saving more than a million lives.
Pyrethroid Resistance - ANSMosquitoes become resistant to pyrethroids. Individual mosquitoes
have genetic mutations that confer resistance. These resistant mosquitoes survive and
reproduce while individuals w/o the mutations die off
West Nile Virus in birds - ANSFound in over 200 bird pieces, especially lethal to crows and blue
jays. Mosquitoes become infected with virus when they bite birds.
West Nile Infections and Mortalities - ANSbetween 1999 and 2012, there have been 37,000
human cases of West Nile virus and 1,500 human deaths in the U.S. and 1/150 people are
infected and get brain related diseases
Ticks - ANSfeed on blood to get protein to make eggs. They anchor their barbed mouthparts
below the skin suck blood. Enlarged (full of blood) after feeding.
Different life stages of a Deer tick - ANS1) Larva (tiny)
2) Nymph (small)
3) Adult Male (Medium)
4) Adult Female (Big)
The Nymph Stage of a Deer Tick - ANSNymph stage of the deer tick most often transmits lyme
disease to humans. Very small and difficult to see. It injects an anesthetic into the skin to mask
the pain of the bite, so a person usually never notices when bitten.
What causes lyme disease? - ANSA corkscrew-shaped bacterium (borrelia burgdorerí)
Transmitted by (backlogged tick) deer tick bite.
White-footed Mice - ANSCarriers of the bacterium that causes lyme disease, are abundance in
small forest fragments in the East and Northeast
Effects of Lyme Disease - ANS- Flu like symptoms
- bull's eye rash at site of bite
- Arthritis-like symptoms in joints, facial palsy, irregular heartbeat
- Bacteria may attack nervous system resulting in behavioral and memory changes
- death is rare
Treatment for Lyme Disease - ANSwith treatment and appropriate antibiotics in the early stages
of lyme disease usually recover rapidly and completely
BUT
patient with certain neurological or cardiac forms of illness may require intravenous treatment
with drugs such as ceftriaxone or penicillin
, Cells of Immune System - ANS- Macrophages
- Helper T cells
- B cells
- Killer T cells
- Memory Cells
These cells destroy proteins that are not you
Immune system response to a Microbial infection - ANS1) Microbe w/ protein coat enters body
and starts to reproduce
2) Macrophages circulante thru body and ingest some of the microbes, alerting Helper T cells by
presenting protein coat
3) Helper T Cells recognize protein coat of microbe and alert T and B cells by making cytokines
4a) B cells make antibodies that neutralize microbes
4a) Killer T cells kill microbe or human cells infected with microbes
4b) Memory B cells remain to provide immunity
4b) Memory T Cells remain to provide immunity
After we become sick, why are we ill for about a week? - ANSAfter infection starts, it takes about
ONE week to make the T cells and B cells necessary to defeat the microbe
Viruses dont have and rely on? - ANSDo not have ribosomes (protein factories within cells) and
rely on host cells for replication
Viruses: - ANS1) insert genetic material into host cell
2)incorporate their genetic material into host cells DNA
3) direct the host cell to make viral proteins and copies of viral genetic material which are
assembled into new viruses
Viral Infection Pathway - ANS1) Viruses penetrate body surfaces and take over cells to produce
more viruses
2) the host cell then ruptures and releases the newly produced viruses
3) although the immune system can defeat most viral infections, some viruses can hide from the
immune system and remain in the body
Shingles is caused by? - ANSThe chickenpox virus that has "hidden" in the body
Chickenpox aftermath affects - ANSAfter having the virus some of the viruses lie dormant in
nerve cells near spinal cord
- years later, the virus reactivates and travels along nerve fibers to skin
- as the virus moves, it causes pain
- when it reaches the skin, it causes a rash and blister
(Hale)
Plague - ANSBroke out in the 1300s and killed 75 million people by the early 19th century. Fleas
were spreading the plague. Modern antibiotics are effective against plague, but if an infected
person is to treated promptly, the disease is likely to cause illness or death.
Fleas spread plague by? - ANSfeeding on blood of mammals like rats, spreading the bacteria
that causes plague.
Malaria - ANSOne of the most deadly diseases in human history. Today it sickens 219,000,000
a year and kills 600,000 people a year, mostly children.
Malaria caused by? - ANSProtozoan (a single celled organism) that infects humans and
destroys red blood cells.
symptoms of malaria - ANSShivering, pain, fever and sometimes death is caused when the red
blood cells burst, releasing a new generation of malarial parasites. When young children are
infected they can have permanent brain damage and death
Historic Effects of Defeat Malaria - ANSPrevention of disease w/ drugs like Chloroquine to kill
malarial parasites.
Control Mosquitos by? - ANSDraining wetlands where mosquitoes breed and using pesticides
like DDT to kill mosquitos
Chloroquine - ANSis a medication to treat or prevent malaria.
How does Chloroquine work? - ANSby interfering w/ the growth of parasites in the red blood
cells of the human body
Malaria is usually spread by? - ANSGetting bitten by a mosquito caring the disease
Resistance to Chloroquine - ANSMalaria strains of plasmodia have become resistant to
chloroquine. Individual plasmodia (the single celled organism that causes malaria) have genetic
mutations that confer resistance. These resistant plasmodium survive and reproduce while
individuals w/o the mutations die off.
DDT - ANSSpray to kill Mosquitoes, but was banned in 1972 in USA
,Pyrethrin Insecticides - ANSwere developed from a natural substance in chrysanthemums.
Thought to be non-toxic to humans but little research in this area has been done. Used for a
decade(s) long campaign against malaria, responsible for saving more than a million lives.
Pyrethroid Resistance - ANSMosquitoes become resistant to pyrethroids. Individual mosquitoes
have genetic mutations that confer resistance. These resistant mosquitoes survive and
reproduce while individuals w/o the mutations die off
West Nile Virus in birds - ANSFound in over 200 bird pieces, especially lethal to crows and blue
jays. Mosquitoes become infected with virus when they bite birds.
West Nile Infections and Mortalities - ANSbetween 1999 and 2012, there have been 37,000
human cases of West Nile virus and 1,500 human deaths in the U.S. and 1/150 people are
infected and get brain related diseases
Ticks - ANSfeed on blood to get protein to make eggs. They anchor their barbed mouthparts
below the skin suck blood. Enlarged (full of blood) after feeding.
Different life stages of a Deer tick - ANS1) Larva (tiny)
2) Nymph (small)
3) Adult Male (Medium)
4) Adult Female (Big)
The Nymph Stage of a Deer Tick - ANSNymph stage of the deer tick most often transmits lyme
disease to humans. Very small and difficult to see. It injects an anesthetic into the skin to mask
the pain of the bite, so a person usually never notices when bitten.
What causes lyme disease? - ANSA corkscrew-shaped bacterium (borrelia burgdorerí)
Transmitted by (backlogged tick) deer tick bite.
White-footed Mice - ANSCarriers of the bacterium that causes lyme disease, are abundance in
small forest fragments in the East and Northeast
Effects of Lyme Disease - ANS- Flu like symptoms
- bull's eye rash at site of bite
- Arthritis-like symptoms in joints, facial palsy, irregular heartbeat
- Bacteria may attack nervous system resulting in behavioral and memory changes
- death is rare
Treatment for Lyme Disease - ANSwith treatment and appropriate antibiotics in the early stages
of lyme disease usually recover rapidly and completely
BUT
patient with certain neurological or cardiac forms of illness may require intravenous treatment
with drugs such as ceftriaxone or penicillin
, Cells of Immune System - ANS- Macrophages
- Helper T cells
- B cells
- Killer T cells
- Memory Cells
These cells destroy proteins that are not you
Immune system response to a Microbial infection - ANS1) Microbe w/ protein coat enters body
and starts to reproduce
2) Macrophages circulante thru body and ingest some of the microbes, alerting Helper T cells by
presenting protein coat
3) Helper T Cells recognize protein coat of microbe and alert T and B cells by making cytokines
4a) B cells make antibodies that neutralize microbes
4a) Killer T cells kill microbe or human cells infected with microbes
4b) Memory B cells remain to provide immunity
4b) Memory T Cells remain to provide immunity
After we become sick, why are we ill for about a week? - ANSAfter infection starts, it takes about
ONE week to make the T cells and B cells necessary to defeat the microbe
Viruses dont have and rely on? - ANSDo not have ribosomes (protein factories within cells) and
rely on host cells for replication
Viruses: - ANS1) insert genetic material into host cell
2)incorporate their genetic material into host cells DNA
3) direct the host cell to make viral proteins and copies of viral genetic material which are
assembled into new viruses
Viral Infection Pathway - ANS1) Viruses penetrate body surfaces and take over cells to produce
more viruses
2) the host cell then ruptures and releases the newly produced viruses
3) although the immune system can defeat most viral infections, some viruses can hide from the
immune system and remain in the body
Shingles is caused by? - ANSThe chickenpox virus that has "hidden" in the body
Chickenpox aftermath affects - ANSAfter having the virus some of the viruses lie dormant in
nerve cells near spinal cord
- years later, the virus reactivates and travels along nerve fibers to skin
- as the virus moves, it causes pain
- when it reaches the skin, it causes a rash and blister
