Diversity in Living Organisms

Plants are autotrophic (make their own food through photosynthesis), while fungi are heterotrophic (obtain nutrition from external sources). Both plants and fungi have cell walls and nuclei, so these cannot be distinguishing features. The mode of nutrition is the fundamental difference.

Virus is an acellular organism.

99% of protoplasm is mainly made up of elements,  which are found in the form of chemical compounds. Both elements and compounds in the unique combination provide living nature to the protoplasm. Carbohydrates, proteins, fats and water are found in it.

In a prokaryotic cell DNA is circular and lies free in the cytoplasm.

All the animals, i.e. star fish, tapeworm, hydra, spider, sponges and planaria have power to regenerate.

Fresh water sponges reproduce by gemmule formation.

This is the correct answer. The process of obtaining food by amoeba is called phagocytosis. It means 'cell feeding'.

Plants are multicellular eukaryotes with cell walls made of cellulose. This is a defining characteristic of the Plantae kingdom. Fungi have cell walls made of chitin, not cellulose. Protists can be unicellular or multicellular but don't all have cellulose walls. Animals don't have cell walls at all.

Kingdom Protista is characterized by unicellular eukaryotic organisms. This includes protozoans, algae, and other single-celled eukaryotes. Fungi can be unicellular (yeasts) or multicellular. Plantae and Animalia are predominantly multicellular kingdoms.

Protists exhibit diverse modes of nutrition. Some are autotrophic (like algae that photosynthesize), while others are heterotrophic (like amoeba that ingest food). This diversity is a key characteristic of Kingdom Protista, making 'Both of (A) and (B)' the correct answer.

Protozoans are single-celled eukaryotic organisms that belong to Kingdom Protista. They are not monerans (which are prokaryotic), nor are they plants or fungi. The term 'protozoan' specifically refers to animal-like protists that are typically heterotrophic and motile.

When classifying organisms, scientists consider characteristics that are fundamental and structural such as mode of nutrition, body design, and level of cellular organization. Maturity of cells is a temporary state during an organism's life cycle, not a classification criterion.

Paramecium is a ciliated protozoan that uses numerous hair-like projections called cilia for locomotion and feeding. These cilia beat in coordinated waves to move the organism through water.

Euglena is a unicellular protist that moves using a whip-like flagella. Bacteria also use flagella but are prokaryotes, fungi are multicellular or unicellular without flagella, and Paramecium uses cilia for movement.

In Whittaker's five-kingdom classification system, kingdom Protista includes unicellular eukaryotic organisms. Fungi include both unicellular and multicellular organisms, while Animalia and Plantae are primarily multicellular.