A is a virus that infects a bacterial cell.

Figure 17.5 Which of the following statements about virus structure is true? a. All viruses are encased in a viral membrane. b. The capsomere is made up of small protein subunits called capsids. c. DNA is the genetic material in all viruses. d. Glycoproteins help the virus attach to the host cell.

The observation that the bacteria genus Chlamydia contains species that can only survive as intracellular parasites supports which viral origin hypothesis? Progressive Regressive Self-replicating Virus-first

Viruses. all have a round shape cannot have a long shape do not maintain any shape vary in shape

Bacilli, which are rod-shaped, spore-forming bacteria, cause _____________________. Lyme disease measles rubella anthrax

Which of the following is NOT used to treat active viral disease? Vaccines Antiviral drugs Antibiotics Phage therapy

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. What measures have been taken to stop BSE?

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. If you were traveling in Europe, would you eat beef? Give sound reasons why or why not.

Jane Doe is infected with HIV. One of her medications is acyclovir, which is a/an ____________________ drug used to treat viral infections or to provide temporary immunity.

Which is true of DNA viruses? They use the host cell's machinery to produce new copies of their genome They all have envelopes They are the only kind of viruses that can cause cancer They are not important plant pathogens.