Static Quiz 31 January 2023 (Environment)

Correct Answer : D
Answer Justification : Learning: The Great Barrier Reef is the world’s largest coral reef system composed of over 2,900 individual reefs and 900 islands stretching for over 2,300 kilometers over an area of approximately 344,400 square kilometers. The reef is located in the Coral Sea, off the coast of Queensland, Australia. The Great Barrier Reef can be seen from outer space and is the world’s biggest single structure made by living organisms.

Correct Answer: B
Justification :
Statement 2: The excess CO2 is used for calcification of reefs and in this way the additional CO2 is taken care of. So, coral reefs are helpful in controlling the Green House Effect as they absorb carom dioxide. Statement 3: They usually form the first barrier against a tsunami or cyclone or sea waves by blocking the force of the wave.
Statement 4: They have the highest primary productivity WITHIN the sea, not outside. Amongst all, estuaries are the one with the highest primary productivity.

Correct Answer: C
Justification: Vaan Island is located 2 km off the Tuticorin coast, Tamil Nadu. It is one of 21 uninhabited islands in the Gulf of Mannar. The objective was to control the erosion of the island and to facilitate coral rehabilitation in surrounding areas. Coral mining was once rampant in this area, and that combined with rising sea levels, has, over the years harmed the island. It is the first time in India protecting and restoring a sinking island. The project has been funded by NAFCC of the Ministry of Environment, Forests and Climate Change (MoEFCC).
Learning: The Gulf of Mannar Biosphere Reserve is the first marine biosphere reserve in Asia, located in the Southern part of the Bay of Bengal.
The reserve covers 10,500 sq. km and has 21 islands with continuous stretches of coral reef. Fauna present includes globally endangered dugong, several species of dolphins and whales and three species of endangered sea turtles. It is a part of UNESCO MAB (Man and Biosphere) program.

Correct Answer : B
Justification: Light is a limiting factor for life in deep oceans. Not all the color components of the visible spectrum are available for marine plants living at different depths of the ocean. Sunlight is broken into its seven component colors as it penetrates through the ocean water by dispersion. Longer wavelengths cannot penetrate deeper whereas shorter wavelengths do.
Algae use photosynthesis to manufacture food. So, the ones utilizing the short-wavelength for photosynthesis survive. Red algae have red pigment (phycoerythrin) which carries out photosynthesis using only short-wavelength light found in greater depths. They can be found as deep as 200 m in ocean water.

Correct Answer: A
Justification & Learning: Phytoplankton, also known as microalgae, are similar to terrestrial plants in that they contain chlorophyll and require sunlight in order to live and grow. Most phytoplankton is buoyant and floats in the upper part of the ocean, where sunlight penetrates the water.

Phytoplankton also requires inorganic nutrients such as nitrates, phosphates, and sulfur which they convert into proteins, fats, and carbohydrates. Phytoplankton is the base of several aquatic food webs. In a balanced ecosystem, they provide food for a wide range of sea creatures including whales, shrimp, snails, and jellyfish.