Protists Knowledge-Based Practice

Questions

1. 1.

   Which cellular feature uniquely characterizes ciliates, such as Paramecium, compared to most other protist groups?

   • A) An external porous test constructed of calcium carbonate through which pseudopodia extend
   • B) A flagellar pocket containing a single large mitochondrion with an organized mass of DNA called a kinetoplast
   • C) A flexible proteinaceous pellicle enabling mixotrophic switches between photosynthesis and phagocytosis
   • D) The presence of two morphologically and functionally distinct types of nuclei, known as a macronucleus and a micronucleus
2. 2.

   Which group of parasitic protists is characterized by a specialized organelle assembly at the cell apex used to invade host tissues, lacks locomotor structures in mature forms, and includes the causative agent of malaria?

   • A) Ciliophora
   • B) Euglenida
   • C) Amoebozoa
   • D) Apicomplexa
3. 3.

   Which group of aquatic protists is characterized by having two distinct flagella positioned in perpendicular grooves—one longitudinal and one transverse—and includes species responsible for toxic marine blooms known as red tides?

   • A) Dinoflagellates
   • B) Euglenids
   • C) Brown algae
   • D) Radiolarians
4. 4.

   Which group of aquatic photosynthetic protists is characterized by cell walls composed of two overlapping valves made of silica?

   • A) Diatoms
   • B) Dinoflagellates
   • C) Euglenoids
   • D) Ciliates
5. 5.

   Which specialized organelle enables freshwater unicellular protists, such as Paramecium, to expel excess water and maintain osmotic balance?

   • A) Food vacuole
   • B) Pellicle
   • C) Micronucleus
   • D) Contractile vacuole

Answers and step-by-step solutions appear after you finish the test.