Unit 2: Microbial Diversity - Practice Quiz

1 Which type of cell lacks a membrane-bound nucleus?

2 Which structure is present in eukaryotic cells but absent in prokaryotic cells?

3 Bacteria are classified as which type of organisms?

4 Which organisms commonly contain membrane-bound organelles?

5 Where is the genetic material located in a typical bacterial cell?

6 Which bacterial shape is spherical?

7 Which bacterial shape is rod-like?

8 What is the main function of bacterial flagella?

9 Which pigment allows many algae to carry out photosynthesis?

10 What is the body of a multicellular fungus commonly called?

11 What are the thread-like structures of most filamentous fungi called?

12 Which organism is a common example of a unicellular fungus?

13 Protozoa are generally classified as which type of organisms?

14 Which structure helps many protozoa move?

15 Which group includes organisms that may produce their own food by photosynthesis?

16 Which statement best describes a virus?

17 What is the protein coat surrounding a virus called?

18 Which types of genetic material can viruses contain?

19 Viruses can reproduce only inside which type of environment?

20 Which feature distinguishes viruses from cellular microorganisms?

21 A microorganism is observed to have a nucleoid region, 70S ribosomes, and no membrane-bound organelles. How should it be classified?

22 A cell contains mitochondria, endoplasmic reticulum, and a nucleus surrounded by a membrane. Which conclusion is most appropriate?

23 Which feature would best help distinguish many archaea from bacteria in a laboratory comparison?

24 A sample from a highly acidic hot spring contains cells with no nucleus and membrane lipids stable at high temperatures. Which group is most likely present?

25 Why can bacteria generally reproduce faster than eukaryotic microorganisms under favorable conditions?

26 A spherical bacterium remains attached after division and forms a chain. Which arrangement is most likely observed?

27 A bacterial cell loses its capsule but remains viable. Which function is most directly reduced?

28 A bacterium has an outer membrane containing lipopolysaccharide. Which additional structural feature is expected?

29 A motile bacterium moves toward a higher concentration of glucose. Which structure most directly supports this movement?

30 A photosynthetic microorganism has chloroplasts and releases oxygen during photosynthesis. Which group best fits this description?

31 A freshwater alga has a rigid wall and stores carbohydrates mainly as starch. Which combination is most consistent with this organism?

32 A fungus grows as branching filaments that form a visible network. What is this network called?

33 Which observation would most strongly indicate that a microorganism is a yeast rather than a filamentous mold?

34 A fungal cell is treated with an agent that disrupts chitin synthesis. Which structure will be most affected?

35 A protozoan uses temporary cytoplasmic extensions to engulf food and move across a surface. Which structure is involved?

36 A protozoan moves rapidly using numerous short projections that beat in coordinated waves. Which structures produce this movement?

37 A particle contains genetic material enclosed by a protein coat but cannot produce ATP or synthesize proteins independently. How should it be classified?

38 A viral genome is composed of RNA rather than DNA. Which statement is most accurate?

39 A virus loses its envelope after exposure to detergent but retains its nucleocapsid. Which property is most likely reduced?

40 A virus infects only liver cells because its surface proteins bind receptors found mainly on those cells. Which concept does this illustrate?

41 A newly isolated cell contains 70S ribosomes, a circular chromosome, ether-linked membrane lipids, and no peptidoglycan. Which interpretation is most defensible?

42 A microorganism is abundant in acidic hot springs, lacks peptidoglycan, and uses membrane proteins adapted to low pH. Which feature would most strongly distinguish it from a bacterium in the same habitat?

43 An environmental sample contains large cells with nuclei, mitochondria, and ribosomes that resemble bacterial 70S ribosomes only inside the mitochondria. Which conclusion best explains these observations?

44 A cell is measured as 2 µm in diameter and contains no membrane-bound nucleus. Which inference is most appropriate?

45 A bacterial population survives antibiotic exposure without acquiring resistance genes or changing its genotype. Which explanation best accounts for this result?

46 A bacterial cell retains crystal violet after iodine treatment and alcohol decolorization. Which structural feature most directly explains this result?

47 A bacterium is resistant to detergents and releases endotoxin when its outer membrane is disrupted. Which component is primarily responsible for these properties?

48 A bacterial mutant lacks functional flagellar hooks but produces normal flagellin. Which phenotype is most likely?

49 A filamentous microorganism has branching hyphae, absorbs organic nutrients, and possesses a cell wall containing chitin. Which classification is best supported?

50 A unicellular eukaryote has chloroplasts, a cellulose-rich wall, and stores carbohydrates as starch. Which inference is most consistent with these traits?

51 A protozoan moves using cytoplasmic extensions that also engulf food particles. Which structure and process are being described?

52 A yeast cell reproduces by an unequal outgrowth that receives a copy of the nucleus before separation. What process is most likely occurring?

53 A photosynthetic microorganism lacks a nucleus but contains internal membranes bearing chlorophyll-like pigments. Which conclusion is most accurate?

54 A fungal culture contains septate hyphae, but cytoplasmic continuity is maintained through pores in the cross-walls. What function do these septa primarily provide?

55 A viral particle contains a nucleic acid genome enclosed by capsid proteins but lacks ribosomes and independent ATP-generating machinery. Which conclusion follows?

56 An enveloped virus loses infectivity after treatment with a lipid solvent, whereas a nonenveloped virus remains infectious. What best explains this difference?

57 A virus has a segmented negative-sense RNA genome. Which activity must be supplied by the virion or acquired immediately after entry before host ribosomes can translate viral proteins?

58 A bacteriophage causes host-cell lysis only after DNA damage activates a host regulatory pathway. Which life-cycle behavior does this observation suggest?

59 Two viruses infect the same cell, and progeny particles contain mixed genetic segments from both parental strains. Which mechanism most directly explains this result?

60 A subviral infectious agent consists only of a short circular RNA molecule with extensive base pairing and no capsid. Which agent best fits this description?