Question

Which one of the following are peculiar organisms with non-green slimy, naked mass of protoplasm and many nuclei having characteristics of both plants and animals?
A. Cyanobacteria
B. Myxomycetes
C. Ascomycetes
D. PPLO

Answer 1

Hint: Kingdom Protista are single celled eukaryotes. Members of Protista are mostly aquatic. This kingdom forms a link between plants, animals and fungi. They have a well-defined nucleus and other membrane bound organelles because they are eukaryotes.

Complete answer:
A. Cyanobacteria: These are the BGA (Blue Green Algae) are photosynthetic autotrophs as they have chlorophyll similar to green plants. They are unicellular organisms and may be found in colonies or filaments. The colony is surrounded by gelatinous sheaths and can fix nitrogen by help of specialized cells ’heterocyst’ present in them. Option (a) is incorrect.

B. Myxomycetes: These are also called Mycetozoa, a phylum of fungus-like organisms within the kingdom Protista, and are commonly called as true slime molds. They exhibit characters of both protozoans (unicellular microorganisms) and fungi. It is a class of slime molds, which were formerly regarded as animals, but now are considered to be plants and are often separated as distinct phylum (Myxophyta). Option (b) is correct.

C. Ascomycetes: These are the sac-like fungi and are mostly multicellular. The unicellular organism, yeast, also belongs to this class. Their mycelium is branched and separate. They may be saprophytic, decomposers, parasitic or coprophilous. Option (c) is incorrect.

D. PPLO: Mycoplasma, or PPLO-Pleuro-pneumonia like Organism belongs to kingdom Monera, and are small parasitic bacteria that lack cell walls, therefore exhibit pleomorphism and are able to survive without oxygen. These can cause pneumonia and urinary tract infection. Option (d) is incorrect.

Hence, the correct answer is (b).

Note: There are different types of classification given by different scientists over the time. But the most efficient one is the ‘Five Kingdom classification’ given by R.H. Whittaker. He classified the organisms by the following criteria: cell structure, body organization, mode of nutrition, mode of reproduction and phylogenetic relationship. The five kingdoms are: Monera, Protista, Fungi, Plantae, Animalia.