8 Some bacteria benefit mammals by helping with —F growth

G defense

H digestion

J respiration

• Kingdom Bacteria has beneficial and harmful members

• The best answer here is H, since digestion systems of mammals contain bacteria.

• Bacteria found in the respiratory system usually result in illness, which would trigger the defenses, not help them.

Practice Question

H. pylori bacteria are known to cause stomach ulcers, which are sores in the lining of the stomach. The sores are vulnerable to damage by stomach acids. A doctor may treat ulcers by prescribing an antibiotic, which willA. neutralize stomach acidsB. stop formation of stomach acidsC. kill the H. pylori bacteriaD. cover sores in the stomach lining

C

Practice Question

Streptococcus infection in a person’s throatcan cause pain and fever. Streptococcus can becontrolled by antibiotics. Streptococcus is a —F virusG bacteriumH protozoanJ fungus

G

Practice Question

Which of the following explains why antibiotics can treat flu-like symptoms caused by bacteria but are ineffective against flu?

A Flu is a response to an antigen.B Antibiotics require time to work.C Antibiotics strengthen antibodies.D Flu is caused by a virus.

D

Viruses differ from bacteria in that all viruses-F cause insect-borne diseasesG can be destroyed by antibioticsH have rigid cell wallsJ must be reproduced in living cells

J

Practice Question

PUBLIC SERVICE ANNOUNCEMENT: Facts

About the Flu Vaccine1. The vaccine may be

administered either as a nasal spray or as an injection.

2. Prior to administration, nasal-spray vaccines must be stored at 15°C or lower.

3. In an experiment, vaccine recipients had 85% fewer flu episodes than nonrecipients.

4. The vaccine virus is heat sensitive and fails to replicate at temperatures of 38°C–39°C.

4 Which statement above makes the most valid argument in favor of receiving the flu vaccine?

F Statement 1G Statement 2H Statement 3J Statement 4This is administration

directions, not a reason to get vaccinated

These are administration directions, not reasons to get vaccinated

Practice Question

Enzymes allow viruses to insert their genetic material into the host cell’s DNA. The virus benefits from this action by —

A acquiring the traits of the host cell B causing the host cell to produce viruses C introducing random deadly mutations into the host cellD turning the host cell into a virus

B

36 Viruses can be transmitted in a variety of ways. The virus that causes SARS (severe acute respiratory syndrome) can be transmitted when an infected person coughs or sneezes. This virus is transmitted in a manner most similar to the transmission of —

F smallpoxG AIDSH West Nile virusJ influenza

17 Which of the following is found in both cells and viruses?

A SilicaB Genetic materialC Digestive cavityD Flagella

The only way living things or viruses can reproduce is to have a blue print and that is stored in genetic material such as DNA or in viruses, RNA.

21 People infected with the human immunodeficiency virus (HIV) have an increased risk of dying from secondary infections. Which of these best explains how HIV increases the danger of secondary infections?

A HIV produces antigens that damage red blood cells.B HIV adds genetic material from harmful microbes.C HIV destroys helper T cells.D HIV consumes beneficial microbes in the body.

Means reduced immune system or . . .

Damage to red blood cells would be effecting the circulatory system.

Adding genetic material would be a mutation not infection

If it only destroyed “helper cells” it would not be an infection

24 Many species of bacteria can be found in the human mouth. Which of these explains the great variety of bacteria in the mouth?

F Large volumes of air cause bacteria to change form.G Salivary glands cause mutations in bacterial

populations.H The presence of nutrients makes the mouth a

favorable habitat.J Calcium in the teeth provides a suitable pH

environment.

Although bacteria mutate quite easily, simply being in air, or near salivary glands is not sufficient to cause a mutation. Mutations occur naturally, but not so as to produce lots of new species in our mouth. Not F or G

Calcium is an element, not an acid or base, so it will not affect pH - Not J

6 Most viruses infect a specific kind of cell. Which of the following are infected by the human immunodeficiency virus (HIV)?

F Helper T cellsG Liver cellsH GABA-receptor cellsJ Red blood cells

Practice Question

Which of these conditions is caused by bacteria? F AIDSG Seasonal allergiesH Dental cavitiesJ Colds

H

Practice Question

Scientists are designing new medicines to fight infectious diseases caused by viruses. One of the most effective ways these medicines could limit the spread of the virus within the body would be to

A. prevent viruses from dividingB. burst cells infected with virusesC. stop viruses from attaching to cellsD. make it easier for viruses to leave cells

C

Practice Question

F Antibiotics have intensified the symptoms of M. tuberculosis infections.

G M. tuberculosis is becoming extinct because of antibiotics.H Antibiotics have caused M. tuberculosis to reproduce at a

faster rate.J M. tuberculosis has developed resistance to antibiotics.

Which of the following conclusions is supported by the information to the right?

J

Practice QuestionLactose is a naturally occurring sugar found in milk.

Some dairy products, such as yogurt, may contain live bacteria. These products are useful to people who lack the ability to digest lactose. What does this information demonstrate?

A Bacteria raise the acidity of processed foods.B Some bacteria interfere with digestion.C Bacteria can prevent insulin production.D Some bacteria are beneficial to human health.

D

Practice Question

Viruses can be transmitted in a variety of ways. The virus that causes SARS (severe acute respiratory syndrome) can be transmitted when an infected person coughs or sneezes. This virus is transmitted in a manner most similar to the transmission of —

F smallpoxG AIDSH West Nile virusJ influenza

J