Given a scientific passage and an answer, generate a question for the given answer.

Input: Consider Input: Passage: The population is an important unit in ecology as well as other biological sciences. How is a population defined, and what are the strengths and weaknesses of this definition? Are there some species that at certain times or places are not in populations?. Answer: cell division

Output: During interphase, the cell undergoes normal growth processes while also preparing for what, by accumulating energy and building blocks of dna?

Input: Consider Input: Passage: There are a variety of substances in foods that the body needs. Any substance in food that the body needs is called a nutrient. There are six major types of nutrients: carbohydrates, proteins, lipids, water, minerals, and vitamins. Carbohydrates, proteins, and lipids can be used for energy. Proteins also provide building materials. Proteins, minerals, and vitamins help control body processes. Water is needed by all cells just to stay alive. Answer: a nutrient

Output: What do you call any substance in food that the body needs?

Input: Consider Input: Passage: The tennis player in Figure below has really worked up a sweat. Do you know why we sweat? Sweating helps to keep us cool. When sweat evaporates from the skin, it uses up some of the body's heat energy. Sweating is one of the ways that the body maintains a stable internal environment. It helps keep the body's internal temperature constant. When the body's internal environment is stable, the condition is called homeostasis . Answer: homeostasis
Output: What is it called when body's internal environment is stable?