Identify the correct statements : [2023]
A. Detrivores perform fragmentation.
B. The humus is further degraded by some microbes during mineralisation.
C. Water soluble inorganic nutrients go down into the soil and get precipitated by a process called leaching.
D. The detritus food chain begins with living organisms.
E. Earthworms break down detritus into smaller particles by a process called catabolism.
Choose the correct answer from the options given below:
C, D, E only
D, E, A only
A, B, C only
B, C, D only
The detritus food chain begins with dead organic matter. It comprises decomposers which are heterotrophic organisms, mainly fungi and bacteria. Bacterial and fungal enzymes degrade detritus into simpler or smaller inorganic substances by a process called catabolism.
The primary producers of the deep-sea hydrothermal vent ecosystem are [2016]
green algae
chemosynthetic bacteria
blue-green algae
coral reefs
Hydrothermal vents are cracks in the ocean floor that emit jets of hot water loaded with minerals and chemosynthetic bacteria. These bacteria are autotrophs that oxidize hydrogen sulphide in vent water to obtain energy, which is used to produce organic material. These chemosynthetic bacteria are the primary producers and form the base of vent food webs. All vent animals ultimately depend on bacteria for food.
Most animals that live in deep oceanic waters are [2015]
tertiary consumers
detritivores
primary consumers
secondary consumers
Benthos is the community of organisms which live on, in, or near the sea bed, also known as the benthic zone. As no light is available at this zone of sea, the energy source for deep benthic ecosystems is often organic matter from higher up in the water column which drifts down to the depths. This dead and decaying matter sustains the benthic organisms, and therefore, most organisms in the benthic zone, i.e., in deep oceanic waters, are scavengers or detritivores.
If 20 J of energy is trapped at producer level, then how much energy will be available to peacock as food in the following chain? [2014]
Plant → Mice → Snake → Peacock
0.02 J
0.002 J
0.2 J
0.0002 J
Herbivores are eaten by primary carnivores. Only 10% of the herbivores' productivity is utilized for raising productivity of primary carnivores. The rest is consumed in ingestion, respiration, maintenance of body heat, and other activities. Higher carnivores similarly are able to retain only 10% of energy present in primary carnivores. It is called the 10% law, which was proposed by Lindemann.
Accordingly, if plant trapped 20 J of energy, mice will have 2 J, snake will have 0.2 J, and hence, peacock will have 0.02 J of energy.
