Contemporary Issues in Biology TCU (Hale) Exam Questions and Answers

Contemporary Issues in Biology TCU (Hale) Exam Questions and Answers Plague - Answer- Broke 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? - Answer- feeding on blood of mammals like rats, spreading the bacteria that causes plague. Malaria - Answer- One 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? - Answer- Protozoan (a single celled organism) that infects humans and destroys red blood cells. symptoms of malaria - Answer- Shivering, 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 - Answer- Prevention of disease w/ drugs like Chloroquine to kill malarial parasites. Control Mosquitos by? - Answer- Draining wetlands where mosquitoes breed and using pesticides like DDT to kill mosquitos Chloroquine - Answer- is a medication to treat or prevent malaria. How does Chloroquine work? - Answer- by interfering w/ the growth of parasites in the red blood cells of the human body Malaria is usually spread by? - Answer- Getting bitten by a mosquito caring the disease Resistance to Chloroquine - Answer- Malaria 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 - Answer- Spray to kill Mosquitoes, but was banned in 1972 in USA Pyrethrin Insecticides - Answer- were 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 - Answer- Mosquitoes 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 - Answer- Found 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 - Answer- between 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 - Answer- feed 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 - Answer- 1) Larva (tiny) 2) Nymph (small) 3) Adult Male (Medium) 4) Adult Female (Big) The Nymph Stage of a Deer Tick - Answer- Nymph 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? - Answer- A corkscrew-shaped bacterium (borrelia burgdorerí) Transmitted by (backlogged tick) deer tick bite. White-footed Mice - Answer- Carriers of the bacterium that causes lyme disease, are abundance in small forest fragments in the East and Northeast Effects of Lyme Disease - Answer- - 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 - Answer- with 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 - Answer- - Macrophages - Helper T cells