1. The answer is A. The eradication of plants in an ecosystem would devastate the food web in the habitat. This is because plants are primary producers and significant as conduits of energy into a food web. Plants convert radiant energy from the sun to biomass through photosynthesis. This energy then transferred up the food chain through various form of interaction such as predation.

2. The answer is B. Global warming causes water at the equator to be even warmer above normal temperatures. This fans the upwelling of cold water from below the ocean floor and causes an even greater disparity of temperatures across the Pacific ocean. This subsequently fans the trade winds hence warming the air even more and causing severe storms.

3. The answer is B. The flooding of the coastal area due to hurricanes destroys the biodiversity of the ecosystem by physically destroying the habitat and by drowning organisms such as affecting a whole species population. This upsets the balance of the ecosystem and makes it prone to even further deterioration.

4. The answer is A. When the surface ocean waters at the Pacific ocean warm at the equator, there is an upwelling of cooler ocean waters from the bottom of the ocean., The warm currents along with trade move towards the east and met the South American coastline where they bring in heavy rainfall. Conversely, the northwestern region of the Pacific experiences drought.

5. The answer is C. Elnino and La Nina occurs at a frequency of approximately two(2) to seven (7) years. The phenomenon usually lasts nine (9) to twelve (12) months. El Ninos are more frequent than La Ninas. Their peak effect is usually felt around December and January. The strongest El Nino was the one that occurred in 1997.