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Correct ANSWER is (a) Climatic conditions

Explanation: The physical and chemical process of BREAK down complex organic REMAINS (dead or decaying ORGANISMS) into inorganic substances is CALLED decomposition. Along with the availability of oxygen, the decomposition also depends on the climatic conditions.

The correct answer is (d) 5

The BEST I can EXPLAIN: The PHYSICAL and chemical PROCESS of break down complex organic remains (dead or decaying organisms) into inorganic substances is called decomposition. The decomposition is a 5 step process. The steps are fragmentation, leaching, catabolism, humification, and mineralization RESPECTIVELY.

Right choice is (b) Mineralization

Easiest explanation: The process of release of INORGANIC substances both MINERALS (H2O, CO2, etc.) and non-minerals from organic matter (e.g. Ca^2+, NH4, Mg^2+, K^+, etc.) is called mineralization. It is the last step in the process of DECOMPOSITION. These minerals are again USED by plants for food production.

The correct choice is (C) Inorganic substance

Explanation: The substances are formed along with HUMUS DUE to the decomposition PROCESS are inorganic nutrients. This GIVES rise to many metal ions such as iron, cobalt, potassium, selenium, zinc, etc.

The correct option is (b) Leaching

The BEST I can explain: The percolation of the SOLUBLE substances formed due to decomposition into deeper layers of soil is called leaching. In this PROCESS, the water-soluble inorganic nutrients get precipitated as unavailable salts by GOING down into the soil horizon.

Correct answer is (c) Humus

Easiest explanation: The dark AMORPHOUS organic MATTER rich in cellulose and lignin that is highly resistant to any microbial action and decomposes at a slower rate is called humus. It is formed due to the DECOMPOSITION of the organic remains such as dead PLANTS remains dead animal remains and FECAL matter.

Right choice is (d) Humification

The explanation is: The process of FORMATION of dark-colored amorphous SUBSTANCE is CALLED humification. This substance is called humus that is highly resistant to any microbial ACTION and decomposes at a slower rate.

The CORRECT option is (c) Fragmentation

The best explanation: The process called when detritivores feed on LARGER pieces and leave smaller FRAGMENTS BEHIND is called fragmentation. It is carried out by many detritivores such as carrion beetles, earthworms, termites, etc.

The correct answer is (d) Catabolism

The explanation: The PROCESS of secretion of digestive enzymes by decomposers to convert insoluble COMPLEX organic molecules into simple soluble organic and inorganic molecules is called catabolism. It is the CATABOLIC METABOLISM in which degradation occurs.

Right ANSWER is (b) Termites

For explanation: AMONG the above-given OPTIONS, a termite is one of the best examples of DETRITIVORES. They are ESSENTIAL as they keep the forests healthy. They feed on dead decaying plants and aerate the soil as they move through it.

Correct answer is (a) Decomposers

Explanation: The organisms that are responsible for the break down complex organic matter (DEAD or DECAYING organisms) into INORGANIC substances are called decomposers (detritivores). The decomposers or detritivores may INCLUDE invertebrates, FUNGUS or bacteria.

Right CHOICE is (b) Decomposition

To explain I would say: The PHYSICAL and CHEMICAL process of break down complex ORGANIC remains (dead or decaying organisms) into inorganic substances is called decomposition. It is CARRIED out by the organisms called decomposers (invertebrates, fungus or bacteria).

The correct OPTION is (d) Detritus

The explanation is: The organic REMAINS such as DEAD plants remain, dead animal remains and fecal matter is called detritus. It acts as the RAW material for various organisms such as decomposers. In terrestrial ecosystems, it is called “soil organic matter” while in the aquatic system it is known as “MARINE snow”.

The correct answer is (B) Earthworm

The best I can explain: The earthworm is SAID to be a farmer’s friend. The earthworm is a tubular, segmented invertebrate organism COMMONLY found in soil that survives on eating live and DEAD organic matter. They improve the health of the soil by break down soil substances and loosening it.

Correct choice is (a) 115 billion TONS

For EXPLANATION I WOULD say: Productivity is the rate of new biomass PRODUCTION by an individual, population, community within an ecosystem. The productivity of landmass is approximately 115 billion tons.

The correct choice is (d) 70%

For EXPLANATION: Almost 70% of Earth’s surface is OCCUPIED by oceans. An ocean is the largest body of water comprising of much of the planet’s hydrosphere. In all, there are 5 oceans on Earth namely Pacific, ATLANTIC, Indian, ANTARCTIC, and Arctic oceans.

The correct answer is (B) 170 billion tons of organic matter

The best I can explain: The net PRIMARY productivity is the energy left after the RESPIRATION i.e. the gross primary productivity SUBTRACTED by respiration losses. It is approximately 170 billion tons of organic matter of the whole biosphere.

The CORRECT answer is (a) Plants

For explanation: The RATE at which solar energy is CONVERTED and stored by the producers per unit AREA over a time period is called primary productivity. It mainly depends on the variety of plant SPECIES residing in a particular area.

The correct CHOICE is (b) Net primary productivity

Explanation: The rate of production of organic matter during photosynthesis is defined as the gross primary productivity (GPP). It is estimated in EITHER the photosynthetic number or CHLOROPHYLL content.

Correct option is (a) Production of C/g/m^2/day

The explanation: The unit of NET productivity is the production of C/g/m^2/day. The rate of storage of ORGANIC matter not USED by consumers (heterotrophs) is called the net productivity.

Right choice is (d) Net productivity

For explanation: The rate of STORAGE of ORGANIC matter not used by consumers (heterotrophs) is called the net productivity. It is equal to the net primary PRODUCTION minus consumption by the heterotrophs in a unit TIME.

Correct option is (b) Net PRIMARY PRODUCTIVITY

Easy EXPLANATION: The balance between photosynthesis and respiration and other plant losses as DEATH is referred to as the net primary productivity. The NPP is the energy left after the respiration i.e. the gross primary productivity subtracted by respiration losses.

The CORRECT OPTION is (c) Secondary CONSUMER

Easiest explanation: A frog that feeds on insects is an example of a secondary consumer. The secondary consumers feed on PRIMARY consumers to fulfill their ENERGY requirements.

Right answer is (B) Grasslands

For explanation I WOULD say: The grasslands contribute to the HIGHEST rate of primary productivity. Grasslands or transitional landscapes are the open areas of land where the vegetation is DOMINATED by grasses and other herbaceous (non-woody) plants.

The correct option is (c) Secondary productivity

To explain: The RATE of production of NEW organic MATTER by heterotrophic organisms (consumers) is called secondary productivity. The secondary producers FEED on primary consumers to FULFILL their energy requirements.

Correct answer is (c) NPP

Easiest explanation: The AVAILABLE biomass for the CONSUMPTION of heterotrophs is the net primary productivity (NPP). The heterotrophs are HERBIVORES and DECOMPOSERS. NPP is the gross primary productivity subtracted by respiration LOSSES.

The correct choice is (d) GPP – R

The EXPLANATION is: NPP is the energy left after the RESPIRATION i.e. the gross primary productivity subtracted by respiration LOSSES. NPP = GPP – R.

The correct OPTION is (d) NPP

Easy explanation: The net primary PRODUCTIVITY is designated by NPP. The net primary productivity is the ENERGY left after the respiration i.e. the GROSS primary productivity subtracted by respiration losses.

Right ANSWER is (c) Net and Gross primary productivity

Explanation: Gross primary productivity and net primary productivity are the two types of primary productivity. The rate of production of organic MATTER during photosynthesis is defined as the gross primary productivity, while the net primary productivity is the energy left after the respiration i.e. the gross primary productivity SUBTRACTED by respiration LOSSES.

The correct option is (d) g^-2 yr^-1 or KCAL m^-2 yr^-1

Easy EXPLANATION: The UNIT of productivity is g^-2 yr^-1 or kcal m^-2 yr^-1. Productivity is the RATE of new biomass production by an individual, population, community WITHIN an ecosystem.

The CORRECT answer is (b) g^-2 or kcal m^-2

The explanation: The unit of PRIMARY PRODUCTIVITY is the WEIGHT (g^-2) or weight (kcal m^-2). The rate at which the solar energy is converted and stored by the producers PER unit area over a time period is called primary productivity.

The correct answer is (a) PRODUCTIVITY

For explanation I would say: Productivity is the RATE of new biomass production by an individual, population, COMMUNITY within an ecosystem. The productivity of an ecosystem DEPENDS on several environmental FACTORS such as light, water, temperature, precipitation, etc.

Correct choice is (c) Uni-directional

To explain I would SAY: The MOVEMENT of energy from the higher trophic levels and its distribution and LOSS as heat to the lower trophic levels in the ENVIRONMENT is unidirectional. It means the energy moves in one direction only that is from higher to the lower-most level.

Right answer is (d) Heterotrophs

Easy explanation: The autotrophic COMPONENTS are consumed by heterotrophs. A HETEROTROPH (consumers) is an ORGANISM that cannot PRODUCE its own FOOD and therefore derives its intake of nutrition from other sources.

The CORRECT choice is (b) Autotrophs

The best explanation: The decomposers DECOMPOSE and mineralize the ORGANIC dead matter. They break down this organic matter into simple components that are reused by autotrophs as their source of NUTRITION and ENERGY.

Correct OPTION is (a) Pond

Easiest explanation: The phytoplankton, zooplankton, and the DECOMPOSERS are COMPONENTS of a pond ecosystem. Phytoplankton is autotrophs; zooplanktons are HETEROTROPHS while the fungi act as decomposers.

Right CHOICE is (B) Sunlight

To explain I WOULD say: Sunlight is the MAIN SOURCE of energy of autotrophs. These are the organisms (producers) that can produce their own food using light, water, carbon dioxide, or other chemicals.

Right option is (a) Fungi

Easiest explanation: The fungi are decomposers of a POND ecosystem. Fungi are heterotrophic, UNICELLULAR eukaryotes that lack chloroplasts. They decompose the dead and decaying MATTER and provide essential nutrients to the PRODUCERS.

The correct answer is (c) Submerged plants

Easy EXPLANATION: The submerged, floating, and marginal plants found at the edges are AUTOTROPHIC components of a POND. These are the organisms (PRODUCERS) that can produce their own food using light, water, CARBON dioxide, or other chemicals.

Right choice is (d) ZOOPLANKTON

The explanation is: The zooplankton is the consumer of a pond ecosystem. It is a MICROSCOPIC, heterotrophic organism that FEEDS on phytoplankton. It is found in the free-swimming and bottom-dwelling FORMS.

Correct option is (c) WATER

The explanation is: Water is an abiotic component of a POND ecosystem. Water is essential for the GROWTH and transfer of gases, nutrients within the ORGANISMS. The pond is an EXAMPLE of a fresh-water ecosystem.

The CORRECT choice is (d) Decomposition

The explanation: The COMPONENTS of the ecosystem are seen to function as a unit when the aspect is decomposition. It is a part of the nutrient CYCLE in which organic substances are broken down into simpler organic MATTER.