Free Kingdom Protista MCQs with Answers

191. Protists are considered a polyphyletic group because they probably originated from

• A. A common moneran ancestor
• B. More than one moneran ancestor
• C. The heritable genetic changes in viruses
• D. The organic substances of the environment

Explanation: Protists are polyphyletic because they arose from multiple independent evolutionary lines among the first eukaryotes, meaning they trace their ancestry back to more than one moneran (prokaryotic) line via various endosymbiotic events.The other options are wrong because: a single ancestor would be monophyletic; organic substances refer to the origin of life (abiogenesis); and viruses are not the ancestors, as endosymbiosis was the key event.

192. Protists that form a monophyletic lineage with plants are

• A. Fucus and Ulva
• B. Ulva and Spirogyra
• C. Polysiphonia and Fucus
• D. Polysiphonia and Spirogyra

Explanation: The protist group closely related to land plants is green algae, including Ulva and Spirogyra. So option B is correct. All other combinations are incorrect, as Fucus is related to brown algae, and Polysiphonia is related to red algae.

193. The groups of protists that act as the major producers of aquatic ecosystems are

• A. Diatoms and Dinoflagellates
• B. Green algae and Zooflagellates
• C. Foraminiferans and Euglenoids
• D. Brown algae and Water molds

Explanation: The correct answer is Option A:diatoms and dinoflagellatesThese groups of protists are primary producers in aquatic ecosystems, responsible for a significant portion of photosynthesis. Diatoms, with their silica cell walls, convert sunlight into energy efficiently, while dinoflagellates contribute to marine plankton. Option B is incorrect because zooflagellates are not photosynthetic. Option C is incorrect because foraminiferans are heterotrophs, and euglenoids, though photosynthetic, are not primary ecosystem producers. Option D is incorrect because water molds are decomposers, and brown algae, while producers, are not widespread enough to be considered major producers in all aquatic ecosystems.

194. African sleeping sickness is caused by which of these human parasites?

• A. Choanoflagellates
• B. Trypanosoma
• C. Trichonymphas
• D. Paramecium

Explanation: Trypanosoma is a protozoan that causes African sleeping sickness, transmitted by the tsetse fly.

195. To which group does Pinnularia belong?

• A. Chrysophyta
• B. Pyrophyta
• C. Rhodophyta
• D. Phaeophyta

Explanation: Pinnularia is part of the diatom group, which falls under the Chrysophyta division. Diatoms are a type of golden-brown algae known for their silica cell walls and aquatic habitat.

196. Dysentery is caused by:

• A. E. coli
• B. Salmonella
• C. Entamoeba histolytica
• D. Bacteroides fragilis
• E. Listeria monocytogenes

Explanation: This protozoan parasite is the correct answer. It is known to cause amoebic dysentery, a severe intestinal infection leading to diarrhea and abdominal pain.

197. Which of the following is not a symptom of malaria?

• A. Headache
• B. Muscular pains
• C. Constipation
• D. Chills

Explanation: Constipation is not typically associated with malaria. Malaria symptoms mainly include fever, chills, headache, and muscle pain.

198. Chlorella is fresh water:

• A. Bacterium
• B. Virus
• C. Fungus
• D. Alga

Explanation: Chlorella is a genus of freshwater green algae. It is a photosynthetic microorganism and belongs to the group of algae, specifically green algae, which are part of the Kingdom Protista.

199. Which of the following is true about amoeba ?

• A. They move by forming specialized cytoplasmic projections called pseudopodia
• B. They have rigid cell wall
• C. They are multicellular organisms
• D. They are autotrophic

Explanation: Amoeba is a unicellular, heterotrophic organism without a rigid cell wall. It moves and captures food by extending pseudopodia (false feet).

200. Which of the following statements is not true for slime molds in their feeding stage, known as a plasmodium?

• A. It ingests bacteria, yeasts, spores and decaying organic matter
• B. Form resistant haploid spores
• C. Undergoes meiosis
• D. Their zygote produces a single nucleated plasmodium

Explanation: Slime molds form diploid spores, not resistant haploid ones.