Final answer:
Doubling time refers to the time required for a population to double in size during exponential growth. The correct answer is B. In 30 years, a population with a doubling time of 10 years will grow by a factor of 8.
Step-by-step explanation:
Doubling time is defined as the time required for a quantity to double in size or value at a constant growth rate. In the context of exponential growth, doubling time refers specifically to the period during which a population doubles in size. Answering your question, the correct definition of doubling time is B. The time required for each doubling in exponential growth.
Given that a population has a doubling time of 10 years, we can calculate its growth over 30 years using exponential growth principles. After one doubling time, which is 10 years, the population grows by a factor of 2. In 30 years, there are three doubling periods (30 / 10 = 3). Thus, we use the formula 2^n, where n is the number of doubling periods, which in this case is 3. This results in 2^3 = 8. Therefore, the population will grow by a factor of 8 in 30 years.