Answer : B

Explanation :
Coral reefs are underwater structures formed by coral polyps, tiny animals that belong to the phylum Cnidaria. Coral polyps secrete a hard, calcium carbonate exoskeleton that provides a framework for the reef. The Great Barrier Reef (Australia) has the world's largest coral reef system, stretching over 2,300 km.

There are four main types of coral reefs:

1. Fringing reefs: These reefs grow directly from the shore.
2. Barrier reefs: These reefs are separated from the shore by a lagoon.
3. Atolls: These reefs form a ring shape around a lagoon.
4. Patch reefs: These reefs are small, isolated reefs that grow on the seafloor.

Coral reefs thrive in tropical and subtropical waters that are:

• Warm: Coral reefs are typically found in waters with temperatures between 18°C and 30°C.
  • Shallow: Coral reefs are usually found in shallow waters, typically less than 50 meters deep.
  • Clear: Clear waters allow sunlight to penetrate, which is essential for photosynthesis by coral algae.
  • Low nutrient levels: Coral reefs are often found in waters with low nutrient levels, which helps to prevent excessive algae growth that can harm corals.

Answer : A

Explanation :
The Kuroshio Current brings warm water from the tropics, which helps to moderate Japan's climate, particularly in the winter. If the current were to weaken, less warm water would be transported to the region, leading to colder winters. Additionally, the current contributes to the high levels of rainfall in Japan by supplying moisture to the atmosphere. A weaker current would likely result in reduced rainfall.

Hence, Option A is the correct answer.

• Option B is incorrect as the Kuroshio Current’s weakening would actually reduce the transport of warm water, making summers cooler, not hotter. The increased humidity point is also wrong because a weaker current would reduce moisture supply, leading to drier conditions, not increased humidity.
• Option C is incorrect as a weaker Kuroshio Current would actually reduce sea surface temperatures, making it less likely for typhoons to form or intensify. Thus, the frequency of typhoons would likely decrease, not increase.
• Option D is incorrect as weaker current would actually reduce nutrient upwelling, leading to lower productivity in the ocean. Additionally, any changes in nutrient availability would take time to affect fish populations, so an "immediate decline" is unrealistic.

Answer : A

Explanation :

• Statement 1 is correct as The Indian Ocean experiences a unique phenomenon where the direction of its currents reverses with the changing seasons. This is due to the seasonal monsoon winds that blow over the region.

During the northeast monsoon (winter), the winds blow from the northeast, causing the currents to flow southward. In contrast, during the southwest monsoon (summer), the winds blow from the southwest, causing the currents to flow northward.

This reversal of currents plays a crucial role in shaping the ocean's circulation patterns, marine ecosystems, and regional climate.

• Statement 2 is correct as The Atlantic Ocean has a higher average salinity compared to the Pacific Ocean. Several factors contribute to this difference:
• Evaporation: The Atlantic Ocean experiences higher evaporation rates, especially in the subtropics, which increases its salinity.
  • Freshwater input: The Pacific Ocean receives more freshwater from rivers, atmospheric precipitation, and melting ice, which dilutes its salinity.
  • Ocean circulation: The Atlantic Ocean's circulation patterns, such as the Gulf Stream, help to transport saltier waters from the equator toward the poles.

Answer : A

Explanation :

• Sal (Shorea robusta) is a deciduous tree shedding its leaves during the dry season.
  • Neem (Azadirachta indica) is an evergreen tree retaining its leaves throughout the year.
  • Banyan (Ficus benghalensis) is also an evergreen tree known for its aerial roots and year round foliage.

Thus, two trees (Neem and Banyan) are evergreen.

Answer : C

Explanation :

• Statement 1 is correct as The Coriolis force deflects ocean currents to the right in the Northern Hemisphere, contributing to the formation of large circular gyres like the North Atlantic Gyre.
• Statement 2 is incorrect as The Coriolis force causes winds to spiral counterclockwise around low-pressure systems in the Northern Hemisphere (clockwise in the Southern Hemisphere).
• Statement 3 is correct as The Coriolis force, combined with temperature gradients, drives the eastward movement of the polar jet stream, which acts as a boundary between cold polar air and warmer tropical air.
• Statement 4 is incorrect as The Coriolis force is weakest at the equator and strongest at the poles, not the other way around. It does not directly affect the speed of trade winds but influences their direction.