Correct Answer:
Option D —
(i), (ii), (iii), (iv)
The vertical layers of the ocean, known as pelagic zones, are arranged based on depth and the amount of sunlight they receive. This classification is a fundamental concept in Oceanography and Marine Biology.
Vertical Arrangement of Ocean Layers
1. Epipelagic Zone (Sunlight Zone)
Depth: Surface to 200 meters.
Characteristics: This is the only layer where enough light penetrates for photosynthesis. It is home to the vast majority of marine life, including plankton, floating seaweed, and large fish.
2. Mesopelagic Zone (Twilight Zone)
Depth: 200 meters to 1,000 meters.
Characteristics: Light is extremely faint. There is not enough light for plants to grow, but many animals here have large eyes or use bioluminescence to see and hunt.
3. Bathypelagic Zone (Midnight Zone)
Depth: 1,000 meters to 4,000 meters.
Characteristics: This layer is in constant darkness. The water pressure is immense, and the temperature is near freezing. Creatures here rely on "marine snow" (detritus falling from above) for food.
4. Abyssopelagic Zone (Abyssal Zone)
Depth: 4,000 meters to 6,000 meters.
Characteristics: This zone remains in perpetual darkness and covers most of the ocean floor.
5. Hadopelagic Zone (The Trenches)
Depth: 6,000 meters to the deepest parts (e.g., Mariana Trench).
Characteristics: Named after Hades, this zone consists of deep-sea trenches and canyons. Life here is sparse and highly specialized to survive extreme pressure.
Answer verified by Quintessence Classes faculty — Karan Nagar, Srinagar.
