Which element is most important for adding strength to hair, feathers, and outer skin? oxygen hydrogen sulfur phosphorus

What have we learned from fossil evidence about evolution? a) it is an abrupt change. b)the process is observable. c) it takes place during one lifetime only. d)the most complex traits are always selected.

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?

Match the functions to the cell types ? contraction and relaxation. conducting electrochemical signals fighting diseases carrying genetic material