Which limiting factor greatly affects the population of grasses and ecosystem? A. Space 46. How does the destructlon of ooral reefa and mangrove foresta oontribute to species B. Sunlight C. Soil Nutrients D. Altitude extinctlon? A. Amount of dissolved oxygen decreases. B. Fish predators become massive in number. C. Breeding grounds and nurseries of marine species are destroyed. D. The oceans and seas become contaminated with heavy metals and other pollutants. 47. Which of the following best explains eutrophication? A. Forests are cleared to make the land available for other purposes B. People collect, capture, or harvest marine organisms such as coral reefs, fish, sea turtles, and others in a large quantity C. The weakening or death of trees caused by Nitrogen Oxides (NOx) and Sulfur dioxide (SO2) that reacts with water, oxygen, and other chemicals in the atmosphere. D. An increase of organic nutrients brought about by the chemicals and garbage thrown into the bodies of water which stimulates the growth of algae and in turn, lessens the available oxygen for other aquatic animals. 48. Which illustrates how the introduction of new species may lead to extinction? A. When a prey species becomes extinct; its predator loses its food source and consequently becomes extinct. B. Amphibian populations have been on the decline worldwide caused by fungal infection of their skin which interferes with osmoregulation C. When a large predator, the Nile perch, was introduced into Lake Victoria, it caused the extinction of half of the species of fish endemic in it. D. When bacteria in a lake increase in number due to continuous decomposition of dead organisms, dissolved oxygen declines, killing all the fishes in it. 49. In what way can deforestation, building of dams, conversion of forest to agricultural lands and urban development could cause species to decrease in number which, eventually, could lead to extinction? A. They pollute the environment causing species to die. B. They cause widespread of diseases which may lead to mass extinction. C. They cause widespread of diseases which may lead to mass extinction. D. They cause widespread of diseases which may lead to mass extinction. 50.Assume two habitats have the same number of species of birds. The first habitat is predominantly one species of bird, with just a few birds of the other species. The second habitat has equal number of all the different bird species found in habitat 1. Will they have the same biodiversity index? If yes, why? If not, which will have the higher biodiversity index, and why? A. Yes, keniISA thev have eyúm B. Yes, they will have the same biodiversihness and species evenness. species. C. No, habitat 1 has a higher diversity because it is predominantıy uin index depends on the most number of counts of one species of the organisms f bird. Diversity community. D. No, habitat 2 has a higher diversity because, aside from having the same number of species of birds as habitat 1, it also has equal numbers of each species. Species richness and species evenness are both measures of biodiversity se they have the same number of