What other organs or body systems incorporate valves how are they used?

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.

How do you transfer mrna into codons ? i'm so confused : (

Why are scientists concerned about the depletion of the ozone levels in the stratosphere?