Which of the following correctly pairs biotic factors with an effect on an ecosystem? a. Biotic factors would increase the average temperature of the ecosystem

b. Biotic factors would decrease the amount of water available for living organisms

c. Biotic factors would increase the number and variety of predators in the ecosystem

d. Biotic factors would decrease the oxygen in the soil causing a decrease in consumers

Which of the following observation darwin shape his concept of descent with modification? a) species diversity declines farther from the equator. b) fewer species live on islands than on the nearest continents. c) birds live on islands located farther from the mainland than the bird's maximum nonstop flight distance. d) south american temperate plants are more similar to the tropical plants of south america than to the temperate plants of europe. e) earthquakes reshape life by causing mass extinctions.