You are given five test tubes, each containing an unknown protist, and your task is to read the following description and match these five protists to the correct test tube. In test tube 1, you observe an organism feeding. Your sketch of the organism looks very similar to Figure 28. When light, especially red and blue light, is shone on the tubes, oxygen bubbles accumulate on the inside of test tubes 2 and 3. Chemical analysis of test tube 3 indicates the presence of substantial amounts of silica. Chemical analysis of test tube 2 indicates the presence of a chemical that is toxic to fish and humans. Microscopic analysis of organisms in test tubes 2, 4, and 5 reveals the presence of permanent, membrane- bounded sacs just under the plasma membrane. Microscopic analysis of organisms in test tube 4 reveals the presence of an apicoplast in each. Microscopic analysis of the contents in test tube 5 reveals the presence of one large nucleus and several small nuclei in each organism. Figure 28.1 Test tube 3 contains Select one: А. Entamoeba. B. Pfiesteria (dinoflagellate). C. Paramecium. D. Navicula (diatom)

What type of micrograph is shown below? Is the organism pictured prokaryotic or eukaryotic? How can you tell?

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

Figure 13.6 Which of the following statements is true? a. Gram-positive bacteria have a single cell wall formed from peptidoglycan. b. Gram-positive bacteria have an outer membrane. c. The cell wall of Gram-negative bacteria is thick, and the cell wall of Gram-positive bacteria is thin. d. Gram-negative bacteria have a cell wall made of peptidoglycan, while Gram-positive bacteria have a cell wall made of phospholipids.