BIOLOGY 1 Marks Question

The pyramid of biomass is inverted in a pond ecosystem because the biomass of fish (top consumer) is far larger than the producers (phytoplanktons).

Forest is the climax community for both successions.

Differences:

S.No.	Standing State	Strndirg Crop
(i)	Standing state refers to the amount of nutrients such as nitrogen, phosphorus, calcium, etc. present in the soil of an ecosystem at a given time.	Standing crop refers to the amount of biomass or organic matter available at a given rophic level/ ecosystem at a given time.
(ii)	It is in the abiotic comPonents.	It is in the biotic components.

The vertical distribution of different species occupying different levels in an ecosystem is called stratification. Trees occupy the topmost vertical layer of a forest, shrubs occupy the second layer and herbs and grasses occupy the bottom most or base layers.

Primary productivity is determined as the amount of biomass or organic matter produced per unit area over a time period by the plants during photosynthesis.

Net Primary Productivity (NPP) is the weight of the organic matter stored by the producers which is available to heterotrophs for consumption. It is equal to the rate of organic matter produced during photosynthesis GPP minus respiratory losses (R), i.e. NPP = GPP - R

Net primary productivity.

Measurement of biomass in terms of dry weight is more accurate because it avoids variations in weights due to seasonal moisture differences.

The entire sequence of communities that change in a given area.

4 × 10¹³kg.

The standing crop is measured as the mass of living organisms or the number in a unit area. The biomass of a species is expressed in terms of fresh or dry weight.

Many organisms occupy positions in different food chains and several food chains become interconnected to form a food web.

Energy exchange and flow of nutrient cycling

The community established at the terminal stage of succession, is called climax community.

'Stratification' in an ecosystem refers to the vertical distribution of different species occupying different levels.

Detritus.

Producers are also called transducers because they are able to change radiant or light energy into chemical form.

He occupies third tropic level, i.e. he is a secondary consumer.

This is an example of primary succession: Because this begins from a state of little or no life.

It is secondary succession.

They are all detritivores, i.e., decomposing organisms which feed on dead remains of plants and animals.

Producers.

Grass (floor of forest) → Amaranthus → Shrubby plants → Teak (tree).

Dissolved carbon in oceans and carbon in rocks, sediments and fossils are the two forms of carbon reservoirs.

It is referred to the transfer of energy (food) from the producers through a series of consumers.

It is in the atmosphere.

Some of the organisms of DFC are prey to the animal of GFC, hence they are interlinked.

Net primary productivity refers to the biomass/ organic matter available at the producer level to the primary consumers, i.e. GPP-Respiratory losses. Gross primary productivity is the rate of production of biomass/ organic matter by producers during photosynthesis.

A considerable amount of gross primary productivity is used by the plants in respiration; so not all primary productivity is available for consumers.

Natural or human induced disturbances like fire, deforestation, etc.

Green algae are autotrophic organisms, i.e. they synthesise their own food with the help of photosynthesis. At deepest layers of ocean, light is absent. So, photosynthesis does not take place there and hence, green algae are not found in deep strata

Ecological succession is a community controlled phenomenon, in which the structure and composition of communities change in an orderly and sequential manner, leading ultimately to the establishment of a climax community.

Population, community, ecosystem, biosphere.

The amount of energy or biomass remaining in a producer after meeting the cost of its respiration is called the net primary productivity.

Lichens.

Crow.

The rate of synthesis of energy containing biomass by any trophic level per unit area in unit time is called its productivity.
It is expressed in terms of g^-2 yr^-1 or kcal m^-2 yr^-1.

It is the amount of living material or organic matter present in an organism, community or biome.

Producer or first trophic level.

Man can be a primary as well as secondary consumer because man eats plants as well as meat of other animals. So, man is herbivores as well as carnivores.

R represents the respiratory losses.

The herbivores (primary consumers) which depend on plants for their food are called primary carnivores. They are also called secondary consumer.

In the given equation for productivity in an ecosystem, GPP-R= NPP. 'R' represents the energy utilised by plants or producers in respiration. It is also referred to as respiration losses.

Dead organic matter or remains of plant such as leaves, bark, flower and dead remain of animals, including faecal matter constitute detritus.

It states that only 10% energy of a trophic level is transferred to the next higher trophic level.

The rate of succession is much faster in secondary succession as the substratum (soil) is already present as compared to primary succession where the process starts from a bare area (rock).

Producers and dead organic matter, respectively.

Fragmentation, leaching, catabolism, humification and mineralisation.

Temperature and soil moisture are the two climatic factors that regulate decomposition.

Fungi and bacteria.