Number b I think is right
D. The initial breakdown of glucose to pyruvic acid. It's the first step of cellular respiration, and also happens to be an anaerobic stage. Hope this helps! :)
Answer: Energy is passed up a food chain or web from lower to higher trophic levels. This loss of energy explains why there are rarely more than four trophic levels in a food chain or web. Sometimes there may be a fifth trophic level, but usually there's not enough energy left to support any additional levels.
Explanation: :) Hope it helps
Answer:
Explanation: Without gene duplication, mutation of genes would not exist. This would prevent organisms from adapting to their environment, making survival much more difficult if not impossible.