How do enzymes facilitate (speed up) chemical reactions

What statements describe a host organism?

In general, characteristics that an organism survive and reproduce become more common over time. what mechanism of evolution causes this?

Suppose you use three different scale to weigh a bag of oranges. one scale says the nag weighs 2.1 lb, and third says it weighs 2.1 lb. the actual weight of the bag of oranges is 2.153 lb. which of the following best decribes these results?