Question

Which of these statements is false?

• A. All prokaryotes classified under kingdom Monera have a cell wall.
• B. All viroids have single-stranded RNA as the genetic material.
• C. All prions don't have nucleic acid as their genetic material.
• D. Unicellular plants have been place in kingdom Protista by Whittaker.

Answer 1

Answer: (A)

The Mycoplasma are organisms that completely lack a cell wall. They are the smallest living cells known and can survive without oxygen. Many mycoplasma are pathogenic in animals and plants. Viroids are smaller than viruses and cause potato spindle tuber disease. It was found to be a free RNA; it lacked the protein coat that is found in viruses, hence the name viroid. The RNA of the viroid was of low molecular weight. In modern medicine certain infectious neurological diseases were found to be transmitted by an agent consisting of abnormally folded protein. The agent was similar in size to viruses. These agents were called prions. The most notable diseases caused by prions are bovine spongiform encephalopathy (BSE) commonly called mad cow disease in cattle. Unicellular plants or algae like Euglena and diatoms are classified under kingdom Protista by Whittaker. They were not included in the plant kingdom due to its members being multicellular entirely, while Monerans are prokaryotic in nature.