Daily Current Affairs Quiz: October 22, 2025

Answer: A [Habitat refers to the physical area where an organism lives, while Ecological Niche describes its role in the ecosystem, including its interactions with other species. ]
Explanation:

Habitat refers to the physical environment in which an organism lives, which can include factors like climate, soil, and water availability. In contrast, an Ecological Niche encompasses more than just the physical space; it includes the role the organism plays in the ecosystem, its interactions with other species, its diet, and its behavior. Therefore, while the habitat is where an organism lives, the ecological niche describes how it lives within its community and ecosystem.

Answer: D [Fish-eating birds]
Explanation:

Mercury undergoes biomagnification in aquatic food chains — its concentration increases as it moves up trophic levels.

1. Phytoplankton absorb mercury from water but in small amounts.
2. Zooplankton feed on phytoplankton and accumulate more mercury.
3. Small fish eat zooplankton, further concentrating mercury.
4. Fish-eating birds (top predators) consume many contaminated fish, leading to the highest mercury concentration in their bodies.

This is a classic example of how pollutants intensify through the food web.

Answer: B [Only two ]
Explanation:

Statement 1 is incorrect: Grasslands are typically found in regions that receive between 25 to 75 cm of rain per year, not exclusively in areas with less than 25 cm of rain.

Statement 2 is correct: Savannas are indeed a type of grassland ecosystem that is characterized by a mixture of grasses and scattered trees, and they are found in both warm and cool climates.

Statement 3 is correct: Grasslands are important carbon sinks. They sequester carbon in their soil and biomass, playing a significant role in mitigating climate change.

Answer: C [1, 3 and 4 only]
Explanation:

Statement 1 is correct: The Ecological Footprint measures how quickly we consume natural resources and produce waste compared to how fast ecosystems can regenerate those resources and absorb the waste. It reflects human demand on nature.

Statement 2 is incorrect: A country’s Ecological Footprint is not always smaller than its biocapacity. In fact, many countries have a footprint larger than their biocapacity, leading to ecological deficits.

Statement 3 is correct: Reducing the Ecological Footprint can be achieved by improving energy efficiency, shifting to renewable energy, reducing consumption, and promoting sustainable practices.

Statement 4 is correct: The concept was introduced in the 1990s by William Rees and Mathis Wackernagel, who developed it as a tool to measure sustainability.

Answer: B [Only two]
Explanation:

Statement 1 is correct: Phytoplankton, microscopic organisms that live in watery environments, are indeed primary producers in marine ecosystems. They use photosynthesis to convert light energy into chemical energy, forming the base of the marine food web.

Statement 2 is incorrect: Zooplankton and phytoplankton do not occupy the same ecological niche. While phytoplankton are primary producers, zooplankton are consumers that feed on phytoplankton and other small organisms.

Statement 3 is correct: Coral reefs are known for their high biodiversity and provide a habitat or niche for a wide variety of marine species, including fish, invertebrates, and algae.