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.
The definition. Biological evolution, simply put, is descent with modification. This definition encompasses small-scale evolution (changes in gene frequency in a population from one generation to the next) and large-scale evolution (the descent of different species from a common ancestor over many generations).