Biodiversity and Conservation

Eradicate

Directions: Some words in the passage below have been highlighted. Select the best meaning for the corresponding word.

All animal life on planet earth depends on sufficient supply of oxygen for its day-to-day survival. The trees that now just sporadically dot our landscapes, but once heavily blanketed earth’s surface, still are able to provide a large portion of oxygen supply. Through a process of photosynthesis, trees take in carbon dioxide from surrounding air and in return create a sizeable amount of oxygen. Ironically, human beings, who cut down large number of trees to create land, shelter, and energy, pose the most significant threat to survival of world–wide tree population.
But humans are not the only forces that threaten the survival of these mighty members of plant kingdom. Lighting, fire, volcanoes and earthquakes not only destroy many square miles of old growth forest in a matter of hours but may prevent new trees from going. Disease causing fungi and insect pests can either eradicate certain types of trees or weaken their branches.     
Climate also determines whether particular species of tree will prosper in a given area. Amount of rainfall and range of temperature also affect distribution of tree species.

Threaten

Directions: Some words in the passage below have been highlighted. Select the best meaning for the corresponding word.

All animal life on planet earth depends on sufficient supply of oxygen for its day-to-day survival. The trees that now just sporadically dot our landscapes, but once heavily blanketed earth’s surface, still are able to provide a large portion of oxygen supply. Through a process of photosynthesis, trees take in carbon dioxide from surrounding air and in return create a sizeable amount of oxygen. Ironically, human beings, who cut down large number of trees to create land, shelter, and energy, pose the most significant threat to survival of world–wide tree population.
But humans are not the only forces that threaten the survival of these mighty members of plant kingdom. Lighting, fire, volcanoes and earthquakes not only destroy many square miles of old growth forest in a matter of hours but may prevent new trees from going. Disease causing fungi and insect pests can either eradicate certain types of trees or weaken their branches.     
Climate also determines whether particular species of tree will prosper in a given area. Amount of rainfall and range of temperature also affect distribution of tree species.

What was/were the common reason(s) of extinction of many animals?

Directions: Read the passage and answer the following question:

When an animal disappears totally from the surface of the Earth, we say that it has become extinct. Dinosaurs used to roam this planet till the last one died millions of years ago. The dodo bird, which used to live in Mauritius, died out in 1681 when pigs destroyed their eggs and their young.
Today, many animals are faced with extinction. The Californian condor, a majestic bird, and the Siberian tiger are two such animals. Certain kinds of woodpeckers and alligators are also on the endangered list. Some of these animals are decreasing in number, because people have been hunting them down for their fur and skin. Others were killed in large numbers in the past, because they posed a danger to human life.

What was the reason of extinction of dodo?

Directions: Read the passage and answer the following question:

When an animal disappears totally from the surface of the Earth, we say that it has become extinct. Dinosaurs used to roam this planet till the last one died millions of years ago. The dodo bird, which used to live in Mauritius, died out in 1681 when pigs destroyed their eggs and their young.
Today, many animals are faced with extinction. The Californian condor, a majestic bird, and the Siberian tiger are two such animals. Certain kinds of woodpeckers and alligators are also on the endangered list. Some of these animals are decreasing in number, because people have been hunting them down for their fur and skin. Others were killed in large numbers in the past, because they posed a danger to human life.

According to the passage, which of the following reasons cannot be attributed to the disappearance of wetlands?

1. The pressure of overpopulation leading to the development of human habitat
2. Over-exploitation of wetlands
3. The negative attitude of the common masses
4. The industrial policies of the states

Directions: Read the passage and answer the question that follows:

Wetlands are indeed the vital link between water and land. It is the collective term for marshes, swamps, and bogs, found along the edges of streams, rivers, lakes and coastlines. Wetlands can be found in nearly every country and climatic zone. Indeed wetlands are found from the Tundra to the Tropics and on every continent. They are so varied. Some are wet all the time. Some wetlands are large and some are very small. Many have been altered by human activities such as farming, building of roads, dams and towns. Wetlands are regarded wastelands sources of mosquitoes, flies, snakes and diseases. People had negative views about them and they eliminated them. Original wetlands have been destroyed; some of them have been converted into farmland, some others filled by industrial wastes.
Wetlands vary widely because of topography, climate, hydrology, water chemistry and vegetation. Wetlands are the coastal mangrove forests, lake marshes and seasonally flooded lands along river courses. Palm swamps, sea grass beds, salt flats, and coral reefs are common wetlands. They are of two types: tidal wetlands and non-tidal (inland) wetlands. Tidal wetlands are found along the Atlantic, Pacific, Alaskan and Gulf Coasts. The salt water and fluctuating water levels create a difficult environment. Some plants have adapted to the environment of saline conditions. Inland wetlands are common in the margins of lakes and rivers. They include wet meadows dominated by herbaceous plants, swamps and shrubs and tall trees. The prolonged presence of water favours the growth of specially adapted plants.
States and tribes play a critical role in the protection and management of wetlands. With the growth of education, people have started understanding ecological processes and their attitude towards wetlands have changed. They have recognised the ecological significance of the wetlands; they are a source of valuable natural wealth. They help regulating water levels within watersheds; reduce flood and storm damages; and provide fish and wildlife habitat. They support hunting, fishing and other recreational activities.

Wetlands are the most productive ecosystems in the world. They have been described as biological supermarkets as they provide great volumes of food and attract many animal species. A variety of insects, amphibians, reptiles, birds, fish and mammals are found in these wetlands. Many species of birds, animals, rely on wetlands for food, water and shelter. The microbes, insects and wildlife are part of global cycles for water, nitrogen, and sulphur. They store carbon within their plant communities and thus help to moderate climate conditions.