Govt. Exams
Entrance Exams
Inverted pyramids occur when individual organisms at lower trophic levels are larger (e.g., one tree supporting many insects).
While multiple factors contribute to ocean health, addressing single-use plastic directly tackles the primary source of marine plastic pollution through policy and behavioral change.
The tragedy of the commons occurs when individuals act in self-interest to exploit shared resources (like fisheries or forests), leading to overall depletion and collective loss.
Himalayan glaciers are melting at accelerated rates due to climate change, threatening water supplies for millions in northern India and affecting downstream agriculture.
Biomagnification causes toxic substances like DDT and heavy metals to accumulate in higher concentrations as they move up the food chain, affecting apex predators most severely.
Understanding ecological terms and their definitions
• (A) Niche breadth = How wide a range of resources a species uses (fixed characteristic)
• (B) Ecological niche = The role/position of a species in its environment (static definition)
• (C) Functional role = The general function a species performs (doesn't emphasize variability)
• (D) Ecological plasticity/versatility = Ability to change role and function based on environmental context
The question emphasizes that a species' role CHANGES depending on conditions — this is the ability to adapt and shift function, not a fixed characteristic. This is plasticity/versatility.
A generalist species like a crow eats different foods in different habitats (urban vs. rural) — demonstrating ecological plasticity, not fixed niche breadth.
Answer: (D) Ecological plasticity or ecological versatility
This law states that two species competing for identical resources in the same habitat cannot coexist; one will be outcompeted.
In unexplained infertility, IVF allows multiple sperm-egg interactions and can overcome subtle defects in gamete interaction that cannot be detected by standard testing.
Cystic fibrosis typically results in congenital bilateral absence of vas deferens (CBAVD), leading to azoospermia with normal seminal fluid parameters (obstructive azoospermia).
IVF is the gold standard for endometriosis-related infertility as it bypasses tubal and peritoneal factors. IUI has lower success rates in endometriosis. GIFT is rarely used now.
