An enzyme speeds up a reaction by A. lowering the activation energy
B. raising the activation energy
C. releasing energy
D. absorbing energy

Ameadow ecosystem includes many species of grasses and small shrubs, several herbivores, and a few carnivores. a fungus colonizes the meadow and kills most of its vegetation. what is most likely to happen to the populations of herbivores and carnivores in the ecosystem? a. the populations of herbivores and carnivores will increase because there will be less competition for chemical energy. b. the populations of herbivores and carnivores will remain stable because the fungus cannot infect these organisms. c. the populations of herbivores will decrease because of vegetation loss, but the population of carnivores will remain stable. d. the populations of herbivores and carnivores will decline because less chemical energy will be stored in the ecosystem.

What adaptation is apparent in the bodies of the three tortoise species shown in figure 16-2

Which set of characteristics best describes sedimentary rock? a) largest type of rock, made of organic matter, hardest type of rock b) often contains layers, forms near sources of water, contains fossils c) least abundant type of rock, made of other rocks, made mostly of minerals d) most abundant type in earth's crust, made of magma/lava, contains no fossils