"suppose you hold a 10 pound weight steadily in your right hand with your elbow slightlly bent, so that you maintain a contraction of your biceps brachii muscle. after some time, you experience pain and it becomes increasingly difficult to keep the weight at the same level. explain why this is so."

When you run, you begin to breathe heavier and faster. your heart beats more quickly, bringing more oxygen to your cells. which organ systems are working together here?

Overtime the pond slowly becomes more acidic due to the release of chemicals from a nearby factory. which of the organisms would most likely survive the change to their environment?

What evidence could be used to convince policy makers to change a shipping lane from going through a whale breeding ground? information on the number of all whale species currently alive information on the number of all whales hit by boats in the given area information on the number of whale deaths in the world's oceans information on the number of whale offspring born every year. (a) scientists could collect and combine data on fish populations all around the world to show that their populations are declining. (b) scientists collect and combine data on fish populations all around the world to show that their populations are increasing. (c) scientists work together and use past data to show that fish populations are becoming locally extinct in some areas. (d) scientists work together and use past data to show that some fish populations are adapting to environmental changes.