Question

Consider the following four statements (1-4), select the correct option stating which ones are true (T) and which ones are false (F)

$\left(1\right)$ An organism at each trophic level depends on those at a higher trophic level for their energy demands.

$\left(2\right)$ Each trophic level has a certain mass of living material at a particular time called the standing crop.

$\left(3\right)$ Each trophic level has a certain mass of non-living material at a particular time called standing state.

$\left(4\right)$ The number of trophic levels in a grazing food chain is not restricted.

• A. $1-T,2-T,3-F,4-F$
• B. $1-F,2-T,3-F,4-T$
• C. $1-T,2-F,3-T,4-F$
• D. $1-F,2-T,3-T,4-F$

Answer 1

Answer: (D)

Standing crop is the total amount of living material in a specified population at a particular time, generally expressed as biomass. The standing crop may show variation at different times of the year. The availability of the inorganic content available to an organism at given time in the ecosystem is referred to as standing state. Nutrients, such as, carbon, nitrogen, phosphorus, calcium, etc. form part of the inorganic content.
The sequential transfer of nutrients and energy in the form of food from one organism to next. The position of organism in a food chain is termed as trophic level. In a typical food chain, the energy that is transferred from one trophic level to the next is always unidirectional and never forms a cyclical pattern. The main source of energy is the sun. As energy transfer in each successive trophic level reduces is only 10% of the previous, number of trophic levels in a food chain is restricted. After 5-6 trophic levels, very low amount of energy will be transferred making it nearly impossible to survive. Food chain starting with a producer is referred to as grazing food chain.