Give one example of natural pollutant.
Volcanic ash is a naturally occurring environmental contaminant.
12 Class
Where was ozone hole discovered?
The discovery of the ozone hole occurred in Antarctica. It was identified as a significant environmental issue. The hole raised concerns about the impact on Earth’s protective ozone layer.
Name any 2 modern techniques of protection of endangered species.
Tissue culture In vitro fertilization of eggs
Discribe carbon cycle and add a note on the impact of human activities on carbon cycle.
Reservoir of Carbon: 1) Carbon, constituting 49% of organisms’ dry weight, serves as the primary component of all organic compounds in protoplasm, making all life forms on Earth carbon-based. 2) Approximately 71% of carbon exists dissolved in oceans, playing a crucial role in regulating atmospheric carbon dioxide levels. 3) Carbon stored in rocks and fossil … Read more
Write important features of a sedimentary cycle in an ecosystem.
Sedimentary cycles primarily involve reservoirs within the Earth’s crust or rocks, and nutrient elements, such as sulphur, phosphorus, potassium, and calcium, are part of these cycles found in the Earth’s sediments. Key characteristics of a sedimentary cycle within an ecosystem include: 1) The Earth’s crust serves as the principal reservoir for minerals like phosphorus, calcium, … Read more
Define decomposition and describe the processes and products of decomposition.
Decomposition: Metabolism involves decomposing complex compounds by taking in raw materials, processing them, and converting them into simpler compounds. Decomposition progresses through five distinct steps or phases in its entirety. Fragmentation: In the early phase of decomposition, detritus undergoes fragmentation as detritivores break it down into smaller pieces. Leaching: Leaching occurs when fragmented particles, which … Read more
What is primary productivity? Give brief description of factors that affect primary productivity.
Primary productivity refers to the rate at which biomass is generated in an ecosystem, expressed as mass per unit surface (or volume) per unit time, such as grams per square meter per day (g/m²/day). The types of plants present in a specific region are influenced by various environmental factors, including temperature, sunlight, salinity, oxygen and … Read more
Define ecological pyramids and describe with examples, pyramids of number and biomass.
Ecological pyramids Ecological pyramids depict the interconnections among various ecosystem components across consecutive trophic levels. Pyramid of numbers: 1. The pyramid of numbers visually represents the numerical relationships between producers, herbivores, and carnivores across trophic levels. 2. As we ascend trophic levels, the organisms’ numbers decrease; for instance, grasses outnumber herbivores, and herbivores outnumber carnivores. … Read more
Distinguish between Food chain and Food web.
Food chain: A food chain represents a straight sequence of organisms designed for the purpose of nourishment. Energy in a food chain follows a direct, unidirectional pathway from lower to higher trophic levels. Members at higher trophic levels consume only one type of organism in a food chain. Calculating energy flow within a food chain … Read more