Answer: It did not distinguish eukaryotes from prokaryotes, unicellular from multicellular, or photosynthetic from non-photosynthetic organisms.
- A It did not distinguish eukaryotes from prokaryotes, unicellular from multicellular, or photosynthetic from non-photosynthetic organisms
- B It mistakenly placed every known bacterial species directly within kingdom Animalia alongside multicellular animals in most cases
- C It systematically and largely excluded flowering angiosperm plants from being classified within kingdom Plantae under typical conditions
- D It relied mainly on molecular DNA sequencing data that was technologically unavailable at the time it was first proposed according to standard textbooks
Correct answer: A. It did not distinguish eukaryotes from prokaryotes, unicellular from multicellular, or photosynthetic from non-photosynthetic organisms
Explanation: The two-kingdom system failed to distinguish between prokaryotes and eukaryotes, unicellular and multicellular organisms, and photosynthetic (green algae) and non-photosynthetic (fungi) organisms, all of which were grouped together as plants.
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.