Which plasma protein is necessary for the process of blood clotting?

Name the following: (a) category of pathogen that causes diseases, like common cold and mumps. (b) the microorganism that requires a host to produce.

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?

The distant ancestors of tigers may have had bodies without stripes. use the theory of natural selection to explain how tigers may have evolved to have stripes.