Biomagnification is the increase in the concentration of pollutants or harmful chemicals within each step of the food chain. The levels of biomagnification will be different at different trophic levels. For example, in a pond of water, DDT was sprayed and the producers were found to have 0.04 ppm concentration of DDT. Since many types of planktons are eaten by some fishes and clams, their body accumulates 0.23 ppm of DDT. Sea gull that feeds on clams accumulates more DDT as one sea gull eats many clams. Hawk, the top carnivore, has the highest concentration of DDT.
Given below are two statements:
Statement I: Gause’s ‘Competitive Exclusion Principle’ states that two closely related species competing for the same resources cannot co-exist indefinitely and competitively inferior one will be eliminated eventually.
Statement II: In general, carnivores are more adversely affected by competition than herbivores.
In the light of the above statements, choose the correct answer from the options given below:
In the equation GPP - R = NPP
GPP is Gross Primary Productivity
NPP is Net Primary Productivity
R here is ________.
Match Column-I with Column-II and choose the correct option:
| Column-I (Minerals) | Column-II (Features) | ||
|---|---|---|---|
| A. | Copper | (i) | Used in manufacturing of steel and plants |
| B. | Bauxite | (ii) | Used in electric and electronic industries |
| C. | Mica | (iii) | Used in electric cables and utensils |
| D. | Manganese | (iv) | Used in aluminium production |
Choose the correct answer from the options given below:
Give reasons:
(i) The sky appears dark to passengers flying at very high altitudes.
At very high altitudes, passengers are above the atmosphere where there is less scattering of sunlight. As a result, they do not see the scattered blue light and the sky appears dark, similar to the condition experienced by astronauts in space.
(ii) 'Danger' signal lights are red in color.
An ecosystem is a structural and functional unit of ecology where the living organisms come in to interact with each other and the surrounding environment.
The structure of an ecosystem is distinguished by the organization of both biotic and abiotic components. This involves the distribution of energy in our environment. It also comprises the climatic conditions prevailing in that particular environment.
There are two main components of the structure of an ecosystem, namely:
The biotic and abiotic components are interconnected in an ecosystem. It is an open system where the energy and components can flow through the boundaries.