Answer: Osmoregulation.
- A Storing reserve food
- B Exchange of gases
- C Cell locomotion
- D Osmoregulation
Correct answer: D. Osmoregulation
Explanation: The contractile vacuole pumps out excess water that enters by osmosis, so it carries out osmoregulation.
Whittaker's five-kingdom system (1969) groups all cellular life by cell structure and nutrition; viruses, viroids, and lichens fall outside this system entirely since they aren't independently classifiable as one of the five.
Concept context
Whittaker's five kingdom system covering Monera, Protista, Fungi, plus viruses, viroids, and lichens. A foundational NEET chapter on how living organisms are grouped.