How many biodiversity hotspots are identified globally, and how many are present in India?

Which condition is necessary for an area to be declared a biodiversity hotspot?

The distribution of biodiversity is:

Which level of biodiversity refers to variation within species that helps in adaptation?

The term Biodiversity was first coined by:

Freshwater ecosystems include which of the following?

Which of the following is not a natural terrestrial ecosystem?

Which one of the following is not correctly matched?

Which of the following nutrient cycles lacks a major gaseous component?

Nitrogen-fixing bacteria like Rhizobium are associated primarily with which part of the nitrogen cycle?

Which of the following correctly describes the direction of energy flow in an ecosystem?

Lindeman’s law in ecosystem energy flow is also known as:

Net Primary Productivity (NPP) can be expressed as:

Consumers in an ecosystem include all of the following except:

Which among the following represents the “producers” in an ecosystem?

Which of the following is not an abiotic factor in an ecosystem?

The term ecosystem was first coined in 1935 by:

Which statement correctly describes the Metalimnion?

1. The Metalimnion is the uppermost layer, characterized by warm, circulating water.
2. It lies below the Hypolimnion, acting as the transition zone to the surface water.
3. The Metalimnion forms the intermediate layer of the lake, marked by a steep fall in temperature.
4. This layer is known for its high oxygen content due to constant mixing with the atmosphere.

Regarding the Epilimnion layer, which of the following statements is correct?

1. It is the bottom-most layer of the lake, characterized by cold, nutrient-poor water.
2. The Epilimnion is the upper layer of the lake, containing freely circulating warm water.
3. It is well-aerated primarily due to decomposition processes occurring at the bottom.
4. The Epilimnion is well-lit but typically poor in dissolved oxygen.

Consider the characteristics of the Hypolimnion layer in a stratified lake. Which statement is accurate?

1. The Hypolimnion is the upper, circulating layer rich in oxygen and nutrients.
2. The Hypolimnion is the bottom layer characterized by cold temperatures and low oxygen levels.
3. Decomposition processes in the Hypolimnion consume nutrients and produce oxygen.
4. The temperature in the Hypolimnion experiences a steep fall with increasing depth.

What are the key factors contributing to pronounced thermal stratification in lakes during summer?

1. Increased solar intensity during summer heats the surface layer significantly, while lower layers remain cooler.
2. The rapid mixing of water layers by strong winds prevents the formation of distinct temperature gradients.
3. The thermally stratified layers offer resistance to mixing by wind, helping to maintain the temperature differences.
4. A decrease in solar radiation during summer leads to the formation of thermal gradients.

Which of the following statements accurately describe summer stratification in temperate lakes?

1. Summer stratification is a phenomenon where lakes develop distinct temperature layers.
2. In temperate regions, thermal stratification is rare and only occurs in very deep lakes.
3. The top meter of the water surface absorbs approximately 90% of solar radiation, leading to its significant heating.
4. Tropical lakes exhibit pronounced summer stratification due to slow mixing rates.

What are the primary reasons for pronounced thermal stratification in lakes during the summer season?

1. Decreased solar intensity leads to greater heating of the surface layer.
2. The surface layer of the water absorbs a significant portion of the solar radiation, leading to increased heating.
3. The lower layers remain comparatively cool due to receiving progressively less solar radiation.
4. The thermally stratified layers offer enhanced mixing by wind.

Identify the correct statements regarding the thermal stratification layers in a lake during summer.

1. The epilimnion is the upper layer, characterized by warm, circulating water, rich in nutrients, and supporting phytoplankton growth.
2. The metalimnion is the intermediate layer where water temperature decreases sharply with increasing depth.
3. The hypolimnion is the bottom layer, which is cold, non-circulating, and typically low in oxygen but rich in nutrients.
4. Phytoplankton predominantly grow in the hypolimnion due to high nutrient availability.

Which of the following statements accurately describe summer stratification in temperate lakes?

1. Summer stratification is pronounced in temperate lakes due to the rapid mixing of water layers.
2. Temperate lakes retain well-defined temperature layers that do not mix rapidly during summer.
3. Tropical lakes exhibit pronounced summer stratification because their layers mix slowly.
4. Summer stratification is rare in deep tropical lakes.

Which of the following statements about dissolved oxygen in lake ecosystems is correct?

1. Dissolved oxygen is generally higher in stagnant lake waters compared to flowing lotic systems.
2. The oxygen content in lakes typically decreases with depth.
3. Only the surface layer of a lake interacts with atmospheric oxygen.
4. Decomposition of organic matter does not affect dissolved oxygen levels.

Regarding the factors influencing zonation in lake ecosystems, which statement is correct?

1. Horizontal zonation in lakes is solely determined by the direct influence of sunlight and temperature.
2. Vertical zonation is a direct result of temperature, sunlight, and oxygen gradients.
3. The distribution of lake organisms does not play a role in horizontal zonation.
4. Dissolved oxygen levels are uniform at all depths in a lake.

Which of the following statements accurately describe the characteristics of lake ecosystems?

1. Lake ecosystems, unlike lotic ecosystems, are characterized by static water bodies.
2. Light penetration in lakes is consistently uniform throughout the water column.
3. Dissolved oxygen levels in lakes are typically higher than in lotic systems due to greater surface area contact with air.
4. Vertical zonation in lakes is primarily influenced by variations in temperature, sunlight, and dissolved oxygen.

Consider the definition of wetlands. Which statement is incorrect?

1. Wetlands can be saturated with water periodically.
2. Wetlands can be artificially created.
3. Wetlands are exclusively land areas completely submerged in water permanently.
4. The water covering wetlands can be up to a depth of 6 meters.

What type of water is typically found in Coastal wetlands?

1. Only freshwater.
2. Saline or brackish water.
3. Purely desalinated water.
4. Water with varying salinity levels.

Which of the following are examples of Inland wetlands?

1. Mangrove swamps
2. Bogs
3. Mangrove Forests
4. Swamps

Identify the correct classification of wetlands based on their location and water type.

1. Inland wetlands are found near the coast and contain saline water.
2. Coastal wetlands are located inland and contain freshwater.
3. Inland wetlands are characterized by freshwater and are situated away from the coast.
4. Coastal wetlands are found near the coast and contain saline or brackish water.

Which of the following statements accurately describes wetlands?

1. Wetlands are areas that are permanently or periodically covered by water.
2. Wetlands can only be natural formations and cannot be artificial.
3. The water in wetlands can be fresh, brackish, or saline.
4. Wetlands are defined as lands saturated with water up to a depth of 10 meters.

Which statement accurately describes 'offstem' reservoirs?

1. Offstem reservoirs are constructed in low land areas by pumping water from a river or underground source.
2. Offstem reservoirs are typically located in upland regions and created by damming.
3. The water source for offstem reservoirs is always a natural spring.

What distinguishes 'onstem' reservoirs from 'offstem' reservoirs?

1. Onstem reservoirs are located in upland areas and formed by damming rivers, while offstem reservoirs are in lowlands and use pumped water.
2. Onstem reservoirs rely on pumping water, whereas offstem reservoirs are naturally formed.
3. There is no significant difference between onstem and offstem reservoirs.

Identify the type of reservoir typically found in India.

1. In India, 'onstem' reservoirs are predominantly found.
2. 'Offstem' reservoirs are the most common type in India.
3. Reservoirs in India are exclusively formed by pumping water from underground sources.

Which of the following best describes the purpose of impoundments?

1. Impoundments are built to meet specific requirements like hydroelectric power generation and water supply.
2. The primary function of impoundments is to serve as natural habitats for wildlife only.
3. Impoundments are solely for recreational activities.

What are artificial lakes created by humans called?

1. Artificial lakes created by humans, both small and large, are referred to as Reservoirs or Impoundments.
2. Impoundments are exclusively natural formations.
3. Reservoirs are only built for water supply purposes.

What is a region where lakes are grouped together called?

Which of the following is given as an example of a crater lake?

What are lakes formed in the crater depression of extinct volcanoes called?

What geological activities can lead to the formation of tectonic lakes?

How old are Lake Baikal and Lake Tanganyika estimated to be?

Lake Baikal in Russia and Lake Tanganyika in Africa are examples of what type of lakes based on their origin?

Which of the following are examples of lentic ecosystems?

Which type of ecosystem includes a static body of water?

What are the primary ways dissolved oxygen is lost from an aquatic ecosystem?

1. Through respiration by aquatic organisms.
2. Through the air-water interface.
3. Through photosynthesis by aquatic plants.
4. Through absorption by the substrate at the bottom of the water body.

How does turbidity affect aquatic ecosystems?

1. It increases the penetration of sunlight, enhancing photosynthesis.
2. It reduces the extent of light penetration, thereby limiting photosynthetic activity.
3. It has no significant impact on light penetration or photosynthesis.
4. It is caused by dissolved gases and does not involve suspended particles.

What defines the photic zone in an aquatic ecosystem?

1. The region where light penetrates sufficiently for photosynthesis to occur.
2. The deepest part of the water body where no light reaches.
3. The layer of water where temperature is consistently low.
4. The area where dissolved oxygen levels are at their highest.

Which of the following are the major limiting factors for the productivity of aquatic ecosystems?

1. Sunlight
2. Temperature
3. Wind speed
4. Atmospheric pressure