Ecology Basics — Set 3
Geography · पारिस्थितिकी की मूल बातें · Questions 21–30 of 50
Which organism is known as the 'Friend of the Farmer' due to its role in soil ecology?
Correct Answer: D. Earthworm
Earthworms are called friends of farmers because they improve soil aeration and fertility by tunneling through the ground. They also break down organic matter into nutrient-rich humus. Their waste, known as castings, acts as natural fertilizer.
What is the primary source of energy for almost all ecosystems on Earth?
Correct Answer: C. Solar radiation
Solar radiation or sunlight is the ultimate source of energy for nearly all life forms. Plants capture this energy through photosynthesis and convert it into food. Exceptions include deep-sea hydrothermal vent ecosystems which rely on chemical energy.
The term 'Biotic Potential' refers to the?
Correct Answer: C. Maximum growth rate of a population under ideal conditions
Biotic potential is the maximum reproductive capacity of an organism under optimal environmental circumstances. It assumes unlimited resources and no predators or diseases. In reality, environmental resistance prevents populations from reaching their full biotic potential.
Which process removes carbon dioxide from the atmosphere?
Correct Answer: D. Photosynthesis
Photosynthesis is the process by which green plants take in carbon dioxide and water to produce oxygen and glucose. It is the primary way carbon is 'fixed' from the atmosphere into the biosphere. This helps in regulating the Earth's carbon cycle and temperature.
The interaction between a shark and a suckerfish (remora) is an example of?
Correct Answer: C. Commensalism
The remora fish attaches itself to the shark for transportation and protection without harming or helping the shark. This is a classic example of commensalism where one species benefits. The shark is largely indifferent to the presence of the remora.
In which ecological interaction do both species benefit from each other?
Correct Answer: D. Mutualism
Mutualism is an interaction that confers benefits on both the participating species. A well-known example is lichens, which represent a mutualistic relationship between fungi and algae. The fungi provide protection and water, while algae provide food.
What refers to the total number of individuals of a single species living in a specific area?
Correct Answer: C. Population
A population consists of a group of organisms of the same species inhabiting the same geographic area at the same time. Factors like birth rate, death rate, and migration influence its size. Ecology at this level focuses on factors affecting population growth.
Which of the following represents a 'Sedimentary' biogeochemical cycle?
Correct Answer: C. Phosphorus cycle
The phosphorus cycle is a sedimentary cycle because its primary reservoir is the Earth's crust (rocks). Unlike the nitrogen cycle, it does not involve a significant gaseous phase in the atmosphere. Phosphorus is released into the soil through the weathering of rocks.
Organisms that can tolerate and thrive in a wide range of temperatures are called?
Correct Answer: C. Eurythermal
Eurythermal organisms are those that can function across a broad temperature spectrum. In contrast, stenothermal organisms are restricted to a very narrow range of temperatures. Most mammals are eurythermal, allowing them to live in diverse climates.
What is the term for the accumulation of a non-biodegradable substance in higher concentrations as it moves up the food chain?
Correct Answer: B. Biomagnification
Biomagnification refers to the increase in the concentration of toxic substances like DDT or mercury at successive trophic levels. Since these chemicals cannot be metabolized or excreted, they accumulate in the fatty tissues of predators. Top predators like eagles and humans are most affected.