13.13–13.15: Most protists are single-celled eukaryotes.

The nucleus is an evolutionary innovation that appeared for the first time in protists.

Question 13.20

Unlike other microbes, archaea are able to thrive:

  • a) in very extreme environments (with respect to temperature, salinity, pressure, etc.).
  • b) only at the typical body temperature of their mammalian hosts.
  • c) inside eukaryotic cell organelles.
  • d) in lakes and rivers (i.e., in fresh water).
  • e) in well-aerated soils.

Question 13.21

Most archaeal species:

  • a) have yet to be discovered.
  • b) are pathogenic.
  • c) are bacteriophages.
  • d) are animal parasites.
  • e) are beneficial to humans.

Question 13.22

All protists are alike in that all are:

  • a) photosynthetic.
  • b) eukaryotic.
  • c) parasitic.
  • d) colonial.
  • e) multicellular.

Question 13.23

Which of the following statements about protists is correct?

  • a) Protists were the first group of organisms to have a nucleus.
  • b) Protists were the first group of bacteria.
  • c) Protists are the only group of photosynthetic archaea.
  • d) Protists are unique among the eukaryote kingdoms in that they are sessile.
  • e) All protists use cilia for feeding.

Question 13.24

Which of the following statements about Plasmodium is correct?

  • a) It causes sickle-cell anemia.
  • b) Because it changes its surface proteins frequently, it is largely invisible to the human immune system.
  • c) It is transmitted by Paramecium.
  • d) It confers resistance to malaria.
  • e) It is most common in North America.

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