ch 23 amp 24 practice test no key

							ch.24 & 25 Baceria and Virus practice test

Multiple Choice
Identify the choice that best completes the statement or answers the question.

____    1. The earliest known group of living organisms on Earth was
           a. viruses.                                   c. bacteria.
           b. fungi.                                     d. protists.
____    2. Bacteria can be classified according to their
           a. type of cell walls.
           b. methods of obtaining energy.
           c. Gram-staining characteristics.
           d. All of the above




____    3. Refer to the illustration above. Which of the organisms shown has the shape called bacillus?
           a. organism 1                                    c. organism 3
           b. organism 2                                    d. None of the above
____    4. Refer to the illustration above. The shape represented by organism 3 is called
           a. coccus.                                       c. bacillus.
           b. spirillum.                                    d. filamentous.
____    5. Bacteria lack a true nucleus and membrane-bound organelles; therefore, they are classified as
           a. prokaryotes.                                  c. anaerobes.
           b. aerobes.                                      d. eukaryotes.
____    6. The cytoplasm of bacteria
           a. contains numerous types of organelles.
           b. is divided into compartments.
           c. has varying numbers of chromosomes, depending on the species of bacteria.
           d. contains a single chromosome.
____    7. Which of the following comparisons is incorrect?

                PROKARYOTES                        EUKARYOTES

           a. smaller                           larger
           b. circular chromosomes              linear chromosomes
           c. binary fission                    mitosis
           d. chloroplasts                      mitochondria
____    8. One difference between human body cells and bacterial cells is that bacterial cells have
           a. an outer cell wall made up of phosphates.
           b. a cell wall made up of peptidoglycan.
           c. no DNA.
           d. no ribosomes.
____    9. Bacterial endospores
           a. occur where there is plenty of available food.
           b. allow certain species to survive harsh environmental conditions.
           c. are similar to human tumors.
           d. can cause growth abnormalities in plants.
____ 10.   Which of the following are used by at least some bacteria for movement?
           a. pili
           b. flagella
           c. cytoplasmic projections
           d. All of the above
____ 11.   Autotrophic eukaryotes and autotrophic prokaryotes differ in that some autotrophic prokaryotes
           a. are decomposers.
           b. can use the energy from inorganic chemicals.
           c. have membrane-bound organelles.
           d. cannot manufacture their own food.
____ 12.   Which of the following conditions would be unsuitable for any kind of bacteria to grow?
           a. temperature of 110ºC (230ºF)
           b. absence of oxygen
           c. pH of 5
           d. None of the above
____ 13.   A pathogen is an agent that is
           a. beneficial to humans.
           b. harmful only to plants.
           c. harmful to living organisms.
           d. nearly extinct.
____ 14.   Which of the following foods is not a fermentation product of bacteria?
           a. sour cream                                    c. milk
           b. a pickle                                      d. yogurt
____ 15.   Antibiotics
           a. include penicillin and tetracycline.
           b. may prevent bacteria from making new cell walls.
           c. can be effective treatments for bacterial diseases.
           d. All of the above
____ 16.   All of the following are habitats of archaea except
           a. volcanic vents.
           b. intestinal tract of cows.
           c. salt lakes.
           d. human skin.
____ 17.   Which of the following is not a way of preventing a foodborne illness at home?
           a. washing kitchen utensils thoroughly in cold water
           b. keeping cooked and raw foods separate during storage
           c. washing fresh fruits and vegetables before eating them
           d. refrigerating leftovers promptly
____ 18.   Viruses are considered nonliving because
           a. they cannot reproduce by themselves.
           b. they are not made up of cells.
           c. they cannot carry out metabolism by themselves.
           d. All of the above
____ 19.   Biologists now know that viruses
           a. are the smallest organisms.
           b. consist of a protein surrounded by a nucleic acid coat.
           c. contain RNA or DNA in a protein or lipid-protein coat.
           d. all form the same crystalline shape.
____ 20.   The capsid of a virus is the
           a. protective outer coat.
           b. cell membrane.
           c. nucleus.
           d. cell wall and membrane complex.
____ 21.   All viruses have
           a. cytoplasm.                                      c. mitochondria.
           b. ribosomes.                                      d. None of the above
____ 22.   Scientists first began to study viruses because they
           a. were seen through a microscope.
           b. could not be seen but caused disease.
           c. formed crystals.
           d. were made of cells.
____ 23.   Viruses that use reverse transcriptase to cause their host cells to transcribe DNA from an RNA template are
           called
           a. bacteriophages.                                 c. retroviruses.
           b. antibodies.                                     d. capsoviruses.
____ 24.   Which of the following contains only RNA?
           a. a prion                                         c. a viroid
           b. a virus                                         d. All of the above
____ 25.   Unlike viruses, prions
           a. are capable of reproducing outside of a host cell.
           b. are composed only of protein.
           c. can cause brain infections.
           d. can be treated with antibiotics.
____ 26.   A typical virus consists of
           a. a protein coat and a cytoplasm core.
           b. a carbohydrate coat and a nucleic acid core.
           c. a protein coat and a nucleic acid core.
           d. a polysaccharide coat and a nucleic acid core.
____ 27.   Animal viruses often infect only specific host cells because
           a. the virus must have the same DNA as the host cell.
           b. the host cell must have specific receptors for proteins on the virus surface.
           c. viruses have receptors for host cell glycoproteins.
           d. the enzymes of the virus can attach only to specific host cells.
____ 28.   In which cell cycle(s) does viral DNA become integrated into the host cell’s DNA?
           a. lytic
           b. lysogenic
           c. neither lytic nor lysogenic
           d. both lytic and lysogenic
____ 29.   Antibiotics are ineffective against viral infections because
           a. host cells protect the viruses.
           b. viruses have enzymes that inactivate the antibiotics.
           c. antibiotics interfere with cellular processes that viruses do not perform.
           d. viral protein coats block the antibiotics from entering the virus.
____ 30.   Which of the following is not a viral disease of humans?
           a. hepatitis
           b. SARS
           c. shingles
           d. All of the above are viral diseases of humans.
____ 31.   Which of the following is not linked to cancer?
           a. Ebola virus                                    c. hepatitis B virus
           b. human papillomavirus                           d. Epstein-Barr virus
____ 32.   Which of the following human activities is most closely associated with the emergence of viruses not
           previously seen in humans?
           a. absence of a vaccination program
           b. crowded living conditions
           c. clearing of forests for housing
           d. eating uncooked meat
____ 33.   HIV causes AIDS by
           a. converting a proto-oncogene to an oncogene.
           b. damaging a person’s blood vessels.
           c. destroying the covering of a person’s nerves.
           d. gradually destroying a person’s immune system.
____ 34.   Which of the following is not a vector of viral diseases?
           a. mosquitoes                                     c. prions
           b. ticks                                          d. humans
____ 35.   Most scientists believe that viruses first appeared on Earth ____ living cells appeared.
           a. after
           b. a very long time before
           c. at the exact time when
           d. immediately before


Completion
Complete each statement.

      36. Spherical bacteria are called ____________________.
      37. Rod-shaped bacteria are called ____________________.
      38. The procedure used to distinguish between two types of bacterial cell wall composition is called
          ____________________.
      39. Protective structures that some bacteria may form under harsh conditions are ____________________.
      40. Bacteria that get carbon from other organisms are called ____________________.
      41. A(n) ____________________ is a substance that can be obtained from bacteria or fungi and can be used as a
          drug to fight pathogenic bacteria.
      42. Many bacteria are ____________________ and must have oxygen to live, whereas other bacteria are
          ____________________ and cannot live where oxygen is present.
      43. An enzyme called _________________________ manufactures DNA that is complementary to a virus’s
          RNA.
      44. ____________________ are viruses that infect bacteria and have a polyhedral head and a helical tail.
      45. The virus that causes AIDS is called _________________________.
Essay

        46. Explain the difference between Gram-positive bacteria and Gram-negative bacteria. Write your answer in the
            space below.
        47. Why are nitrogen-fixing bacteria important to Earth’s ecosystems? Write your answer in the space below.
        48. Suggest a reason why bacteria that are resistant to antibiotics are becoming common in hospitals. Write your
            answer in the space below.
        49. Explain why viruses are not considered to be living organisms, and why they are nonetheless included in the
            study of biology. Write your answer in the space below.


Problem

        50. A new disease has suddenly appeared and scientists are trying to determine whether the disease agent is a
            virus or a bacterium. They collect the following information:

             1.      The disease can be transmitted through the air.
             2.      The disease agent is too small to be seen under a light microscope.
             3.      There are no known antibiotics that are effective against the disease.
             4.      The genetic material of the disease agent is DNA.
             5.      The disease agent cannot be cultured using any known culture medium.

             Is the disease agent most likely a bacterium or a virus? Explain your answer. Write your answer in the space
             below.