The main function of the excretory system is to

Apart of an ecosystem that can restrict the growth of a population is referred to as

The cluster of developing cells from conception until birth is called an

An ecologist studied the same species of deer during the summer and the winter. she noticed that during the summer, when there was plenty of food, the deer were energetic and playful. however, during winter when food was scarce, the deer moved more slowly and did not run unless they needed to escape a predator. which scientific fact is best supported by her observations?