The second trophic level in a lake is-
(a) Phytoplankton
(b) Zooplankton
(c) Benthos
(d) Fishes
(a) Phytoplankton
(b) Zooplankton
(c) Benthos
(d) Fishes
Solution and Explanation
(b) Zooplankton
Zooplankton are primary consumers in aquatic food chains that feed upon phytoplankton. Therefore they are present at the second trophic level in a lake.
Top Questions on Eco-System
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:
- NEET (UG) - 2023
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- Identify the correct statements:A. Detrivores perform fragmentation.B. The humus is further degraded by some microbes during mineralization.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:
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In the equation GPP - R = NPP
GPP is Gross Primary Productivity
NPP is Net Primary ProductivityR here is ________.
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- Detritivores breakdown detritus into smaller particles. This process is called:
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- 'Bad Ozone' is found in
Questions Asked in CBSE CLASS XII exam
A school is organizing a debate competition with participants as speakers and judges. $ S = \{S_1, S_2, S_3, S_4\} $ where $ S = \{S_1, S_2, S_3, S_4\} $ represents the set of speakers. The judges are represented by the set: $ J = \{J_1, J_2, J_3\} $ where $ J = \{J_1, J_2, J_3\} $ represents the set of judges. Each speaker can be assigned only one judge. Let $ R $ be a relation from set $ S $ to $ J $ defined as: $ R = \{(x, y) : \text{speaker } x \text{ is judged by judge } y, x \in S, y \in J\} $.
- CBSE CLASS XII - 2025
- Relations and Functions
Given below is a heterogeneous RNA formed during Eukaryotic transcription:
How many introns and exons respectively are present in the hnRNA?
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- Eukaryotic Transcription
- Four friends Abhay, Bina, Chhaya, and Devesh were asked to simplify \( 4 AB + 3(AB + BA) - 4 BA \), where \( A \) and \( B \) are both matrices of order \( 2 \times 2 \). It is known that \( A \neq B \) and \( A^{-1} \neq B \). Their answers are given as:
A certain reaction is 50 complete in 20 minutes at 300 K and the same reaction is 50 complete in 5 minutes at 350 K. Calculate the activation energy if it is a first order reaction. Given: \[ R = 8.314 \, \text{J K}^{-1} \, \text{mol}^{-1}, \quad \log 4 = 0.602 \]
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- Using integration, find the area of the region bounded by the line \[ y = 5x + 2, \] the \( x \)-axis, and the ordinates \( x = -2 \) and \( x = 2 \).
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- Evaluation of Definite Integrals by Substitution
Concepts Used:
Ecosystem
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.
Structure of the Ecosystem:
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:
- Biotic Components
- Abiotic Components
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.