What does it mean when it says a carrying capacity of 50

Factors that can increase mutation rates a. high temps b. low temps c. food additives d. uv rays

What do your cells need to live? a. carbon dioxide b. carbon c. air d. oxygen

Ruby is conducting an investigation. an advantage of her design is that she can use a large range of variables, with that she can not be sure that one variable is the cause of another. what kind of investigation is ruby most likely conducting?