According to the 10% law given by Lindeman, only 10% of the energy is transferred to the next trophic level.
(i) Name the process by which an organism produces energy.
(ii) What is the most common substrate used in this pathway?
(iii) Which biomolecule is also known as energy currency of the cell?

Decomposition is the process of breaking down of complex organic matter into inorganic substances. Different steps involved in the process of decomposition are fragmentation, leaching, catabolism, humification and mineralisation. Fragmentation is the breakdown of detritous (dead remains and faecal matter)with the help of detrivores e.g.earthworm.With reference to the above paragraph, answer the questions that follow.
(i) State the phylum and scientific name of earthworm.
(ii) The process of fragmentation involves the coordinated function of its digestive and excretory system.Mention the location of oesophagus, integumentary nephridia, typhlosole and gizzard in the earthworm.
(iii) Why does an earthworm die in sunlight?

Nutrients are essential for growth of producers, i.e. for the primary productivity of the ecosystem. The inorganic elements required by the plants present in the soil in the form of minerals are called mineral elements or mineral nutrients. Some of these mineral elements are nitrogen, sulphur, calcium, iron and manganese.State the deficiency symptoms of all elements mentioned above

(i) Define pioneer species.
(ii) Among bryophytes, lichens and fern, which one is a pioneer species in a xeric succession? And why?

Explain why ecological succession will be faster in a forest devastated by fire than on a bare rock? Also, compare succession in case of an abandoned land after floods with that on a bare rock?