# of Bacteria A B C D Time

Bioremediation includes. the use of prokaryotes that can fix nitrogen the use of prokaryotes to clean up pollutants the use of prokaryotes as natural fertilizers All of the above

At the health center, a fecal sample was taken from a feverish student. Organisms with corkscrewlike flagella and no endomembranes but with cell walls that lack peptidoglycan were isolated as the cause for the illness. These organisms probably belong to the group: a. chlamydias. b. spirochetes. c. Euryarchacota. d. Cyanobacteria. e. Archaea.

Mention three differences between bacteria and archaea.

Describe briefly how you would detect the presence of a non-culturable prokaryote in an environmental sample.

Which species does not cause human disease? a. Toxoplasma gondii b. Entamoeba histolytica c. Dictyostelium discoideum d. Trichomonas vaginalis

The term _________________________________ means pertaining to a virus. viral virile

There have been recurring cases of mad-cow disease in the United Kingdom since the mid-1990s. Mad-cow disease is caused by a prion, an infectious particle that consists only of protein. In 1986, the media began reporting that cows all over England were dying from a mysterious disease. Initially, there was little interest in determining whether humans could be affected. For 10 years, the British government maintained that this unusual disease could not be transmitted to humans. However, in March 1996, the government did an about-face and announced that bovine spongiform encephalopathy (BSE), commonly known as mad-cow disease, can be transmitted to humans, where it is known as variant Creutzfeldt-Jakob disease (VCJD). As in cows, this disease eats away at the nervous system, destroying the brain and essentially turning it into a spongelike structure filled with holes. Victims experience dementia; confusion; loss of speech, sight, and hearing; convulsions; coma; and finally death. Prion diseases are always fatal, and there is no treatment. Precautionary measures taken in Britain to prevent this disease in humans may have begun too late. Many of the victims contracted it over a decade earlier, when the BSE epidemic began, and the incubation period is long (VCJD has an incubation period of 10 to 40 years). A recent study concluded that 1 in 2,000 people in Great Britain carry the abnormally folded protein that causes VCJD. In spite of these numbers, the death rate from VCJD remains low. It is not clear whether this means that the incubation period for the disease is much longer than previously thought, or whether they may never develop the disease. How can a prion replicate itself without genetic material?

Synthetic compounds found in an organism but not normally produced or expected to be present in that organism are called _____________. pesticides bioi emediators recalcitrant compounds xenobiotics

Prokaryotes stain as Gram-positive or Gram-negative because of differences in the_______. a. cell wall b. cytoplasm c. nucleus d. chromosome