Is an aquarium a complete ecosystem?
Aquarium is a man made ecosystem (artificial). If an ecosystem possess all physical and biological component, then it is said to be complete. Since aquarium has biotic (plants and fishes) and abiotic component (air, water) required for survival of fishes, so it is an complete ecosystem.
What could be the reason for the faster rate of decomposition in the tropics?
Tropics are characterised by high temperature and moisture and soil is rich in humus and minerals. As the decomposition rate is regulated by climatic factors, thus optinum temperature and humidity enhance the activity of decomposrs while the dead remain is also available in rich amount, which supports the faster rate of decomposition in the tropics.
Human activities interfere with carbon cycle. List any two such activities.
Two human activities that interfere with carbon cycles are
(i) Rapid deforestation and
(ii) Massive burning of fossil fuel for energy and transport.
Flow of energy through various trophic levels in an ecosystem is unidirectional and non-cyclic. Explain.
Flow of energy in an ecosystem is always unidirectional, i.e., energy flow in one way and is noncyclic, like
$$ \underset{\text { Ist Trophic level }}{\text { Plants }} \longrightarrow \underset{\text { Ilnd Trophic level }}{\text { Herbivore }} \longrightarrow \underset{\text { Ill rd Trophic level }}{\text { Carnivore }} \longrightarrow \underset{\text { IVth Trophic level }}{\text { Top carnivore }} $$
As the energy content is decreasing from lst trophic level to next trophic level and so on, thus the energy cannot pass in reverse direction.
Apart from plants and animals, microbes form a permanent biotic component in an ecosystem. While plants have been referred to as autotrophs and animals as heterotrophs. What are microbes referred to as? How do the microbes fulfill their energy requirements?
On the basis of nutrition, organisms are classified as autotrophs and heterotrophs. Autotrophs are further categorised into photoautotrophs and chemoautotrophs, while heterotrophs may be parasite pred or a saprophyte etc.
Microbes are saprotrophs and derive nourishment or energy from dead organic matter or remain of plants and animals and this digestion is extracellular.