Previous Year Questions

Question :

Directions : Read the following passage carefully and answer the questions that follow.

The mangrove is a unique kind of tree. Found in tropical and subtropical latitudes, they grow in saltwater that is up to 100 times saltier than other plants can handle and contain a complex system to filter that salt, which allows them to survive in conditions most plants would find inhospitable. There are over eighty species of mangroves, located all over the world from Florida to Bangladesh to the Galapagos Islands. Mangroves are not only pretty to look at, but they also serve a lot of important roles in our ecosystem. They provide a habitat for wildlife such as fish, birds, deer, and insects. They also stabilize shorelines, protect against storm surges, and improve water quality. But even though these plants can do a lot, they also face threats due to climate change and building developments. Mangroves are so resilient due to a few factors. First of all, they can deal with saltwater, in some cases by filtering out as much as 90 percent of the salt in the seawater where they live. Mangroves are also able to hoard freshwater so they can go for long times without it. Their root systems are unique in other ways, too. These systems, called prop roots, arch out over the water, providing both structural support and oxygen for the plant. Some of them also have pencil-sized roots that they use as breathing tubes which allow them to get oxygen in spite of being flooded daily. Even though mangroves are so tough, they are also facing a number of unprecedented challenges that threaten their survival. One of these is developments built next to mangroves. When this happens, it alters their hydrology, meaning the distribution of water in their environment. These developments tend to shunt their stormwater into mangrove systems. Because a mangrove's upper trunk and leaves live above the waterline, when the water gets too high, they essentially drown. And because the gaseous exchange in their root system gets blocked, the soil gets bad, and it results in a sulphury, eggy smell as well.

According to the passage, what is the role of mangroves in our environment?