Chemosynthetic bacteria are capable of oxidising various inorganic substances such as nitrates, nitrites and ammonia and use the energy released for their ATP production. So, they are autotrophs and not heterotrophs.

The common or vernacular names changes with the change in place, causing confusion regarding the identification of specific specimen, whereas the complex scientific names are in latin and universally accepted and understood. Hence, scientific names are preferred over the common vernacular names.

Viruses are considered as living when they are inside a host but outside any host they are referred to as non-living due to their

(a) inert nature

(b) inability to reproduce

(c) lack of cellular organisation

(d) inability for growth and cell division

These characters potraited by viruses make them identical to non-living organisms. Viruses are considered a connecting link between living and non-living organisms.

In the five kingdom classification given by Whittaker four kingdom belongs to eukaryotes, i.e., Protista, Fungi, Plantae and Animalia, except for the kingdom-Monera that belongs to prokaryotes.

Eukaryotic organism are those that possess

(i) An organised nucleus

(ii) Possess double envelop system

(iii) Presence of cell wall

(iv) Membrane bound organelles are present.

Diatoms and desmids are inducted under chrysophytes, kingdom-Protista. These are the main producers in the ocean. They prepare food not only for themselves but also for the other life forms in the ocean. This is the reason they are also called as 'pearls of ocean. Body of diatoms is covered by siliceous shell known as frustule. 'Diatomaceous earth' is the accumulation of large deposits of diatoms that forms a siliceous covering extending for several 100 m formed in billions of years. The material obtained from these deposits is used in polishing and filteration of oils and syrups.