7 public questions tagged with this topic.
Ecological pyramids represent the relative amount of energy, biomass, or number of organisms at different trophic levels in an ecosystem.
Ref: NCERT Class 12 Biology Chapter 12: Ecosystem Ecological Pyramids - Number Biomass Energy
Exponential growth occurs when resources are abundant and population size increases rapidly without limitation.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Population Growth - Exponential and Logistic Models
Exponential growth occurs under ideal conditions with unlimited resources, producing a J-shaped curve.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Population Growth - Exponential and Logistic Models
A climax community is a stable and mature ecological state reached at the end of succession.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Population Growth - Exponential and Logistic Models
Carrying capacity (K) is the maximum population size that an environment can support based on resource availability.
Ref: NCERT Class 12 Biology Chapter 11: Organisms and Populations Population Growth - Exponential and Logistic Models
Allogenic succession is driven mainly by forces external to the resident community, including erosion, sediment deposition, flooding, climatic shifts, or changes in hydrology. Such abiotic processes alter habitat conditions independently of biological modification and can redirect community composition. A disturbance changes the availability of space, resources, and biological legacies, creating opportunities for colonization. Whether succession is primary or secondary depends chiefly on the starting substrate and survival of soil, not simply on the identity of the disturbance. Colonists must arrive, establish, reproduce, and interact with residents; meanwhile they alter nutrient cycling, shade, moisture, and physical structure. These feedbacks create directional replacement, although repeated disturbance or environmental change may interrupt, reverse, or redirect the sequence. In this context, the keyed term, Abiotic factors like erosion, identifies the relevant mechanism or quantitative relationship and links the observed pattern to its underlying ecological cause. The distinction is testable by measuring changes in organisms, resources, or process rates through time rather than relying on the label alone.
Ref: Ecology: Concepts and Applications, Molles, 9th Ed., Ch. 20
Energy flow is a fundamental functional process that sustains ecosystem organization. Producers capture solar energy through photosynthesis, or chemical energy through chemosynthesis, and store part of it in organic molecules. Consumers and decomposers transfer that chemical energy through feeding and decomposition, while respiration at every trophic level releases much of it as heat. Because heat cannot be completely recycled into biological work, energy moves directionally and requires continual input. This flow constrains food-chain length, biomass at higher trophic levels, and rates of production and nutrient cycling. Biotic components are the living organisms, and abiotic components include light, water, minerals, and climate; both are structural parts of an ecosystem rather than a single process. “Functional units” is too vague to identify the mechanism. The wording that energy flow “regulates” all ecological processes is broader than ideal, since matter cycling and interactions also regulate systems. Nevertheless, energy transfer is the listed functional component that powers metabolism and thereby supports life across the ecosystem.
Ref: Ecology: From Individuals to Ecosystems, Begon et al., 5th Ed., Ch. 17
