Cervical lymphadenitis is usually caused by a viral upper respiratory infection. The key symptom of lymphadenitis is the presence of a painful mass in the cervical area, often accompanied by fever, runny nose, sore throat, and cough.
Question and answer. Which of the following defines evolution? a change in environmental conditions a change in an animal's physical traits a change in a population's gene pool a change in an individual's genetic. makeup. Evolution is a change in a population's gene pool.
Evolution is a scientific theory used by biologists. It explains how living things change over a long time, and how they have come to be the way they are. Earth is very old. By studying the layers of rock that make up Earth's crust, we can find out about its past. This kind of research is called historical geology.