Hormones travel from endocrine glands through bloodstream to organs.

Which of the following statements is true about the relationship between genetic variation and natural selection? a. genetic variation must be present in a population before natural selection can act on it. b. genetic variation arises in a population as a result of natural selection. c. natural selection can act on a population whether there is genetic variation within the population or not. d. after natural selection acts on a population, the amount of genetic variation in the population always increases.

Abiologist counts the number of rabbits in a population each year and observes a decrease in population. since the coyote population has exploded, the biologist concludes that the coyote population has had a negative interaction with the rabbit population. which describes the biologist’s actions? a.) experimentationb.) inferencec.) observationd.) interacting

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.