Why are infectious diseases more common in developing nations than in the United States today?

A symbiotic relationship where both of the coexisting species benefit from the interaction is called.__________ commensalism parasitism mutualism communism

Match each disease with the type of pathogen that causes it. Choices may be used more than once. ___tuberculosis a. virus ___AIDS b. bacteria ___influenza flu ___Lyme disease ___cholera

Organisms most likely to be found in extreme environments are. fungi bacteria viruses archaea

Should he go ahead and enroll on the chance that he would receive the DNA vaccine and that it would be more effective than chemotherapy? Bruce and his parents moved to a semi-tropical region of the United States when he was about 3 years old. He loved to be outside year-round and swim, surf, snorkel, and play baseball. Bruce was fair-skinned, and in his childhood years, was sunburned quite often. In his teen years, he began using sunscreens, and although he never tanned very much, he did not have the painful sunburns of his younger years. After graduation from the local community college, Bruce wanted an outdoor job and was hired at a dive shop. He took people out to one of the local reefs to snorkel and scuba dive. He didnt give a second thought to sun exposure because he used sunscreen. His employer did not provide health insurance, so Bruce did not go for annual checkups, and tried to stay in good health. In his late 20s, Bruce was injured trying to keep a tourist from getting caught between the dive boat and the dock. He went to an internist, who treated his injury and told Bruce he was going to give him a complete physical exam. During the exam, the internist noticed a discolored patch of skin on Bruces back. She told him that she suspected Bruce had skin cancer and referred him to a dermatologist, who biopsied the patch. At a follow-up visit, Bruce was told that he had melanoma, a deadly form of skin cancer. Further testing revealed that the melanoma had spread to his liver and his lungs. The dermatologist explained that treatment options at this stage are limited. The drugs available for chemotherapy have only temporary effects, and surgery is not effective for melanoma at this stage. The dermatologist recommended that Bruce consider entering a clinical trial that was testing a DNA vaccine for melanoma treatment. These vaccines deliver DNA encoding a gene expressed by the cancer cells to the immune system. This primes the immune system to respond by producing large quantities of antibodies that destroy melanoma cells wherever they occur in the body. A clinical trial using one such DNA vaccine was being conducted at a nearby medical center, and Bruce decided to participate. At the study clinic, Bruce learned that he would be in a Phase Ill trial, comparing the DNA vaccine against the standard treatment, which is chemotherapy, and that he would be randomly assigned to receive either the DNA vaccine or the chemotherapy. He was disappointed to learn this. He thought he would be receiving the DNA vaccine.

Mr. Tseng died of cholera during a sudden and widespread outbreak of this disease in his village. Such an outbreak is described as being a/an ___________________________.

If your father were diagnosed with an inherited disease that develops around the age of 50, would you want to be tested to find out whether you would develop this disease? If so, when would you want to be tested? As a teenager or sometime in your 40s? If not, would you have children?

Which of the following is not a way that humans have increased the carrying capacity of the environment? agriculture using large amounts of natural resources domestication of animals use of language

A fungus that climbs up a tree reaching higher elevation to release its spores in the wind and does not receive any nutrients from the tree or contribute to the tree's welfare is described as a. commensal mutualist parasite pathogen

Vitamin-producing E. coli cells in your gut are ________. a. normal microbiota c. proteobacteria b. chemoheterotrophs d. all of the above