Which of the following are the three basic variables that make up the life history of an organism?

• A. Body size, metabolic rate, and lifespan
• B. Age at first reproduction, frequency of reproduction, and number of offspring per reproductive event
• C. Genetic diversity, mutation rate, and population size
• D. Habitat preference, diet, and migration pattern

Answer: (B)

Verified step by step guidance

1. Understand the concept of 'life history' in biology. Life history refers to the traits that affect an organism's schedule of reproduction and survival, which are shaped by natural selection to maximize fitness.
2. Identify the key variables that influence life history. These variables typically include factors related to reproduction and survival, as they directly impact an organism's ability to pass on its genes to the next generation.
3. Analyze the options provided. For example, 'Body size, metabolic rate, and lifespan' are important biological traits but do not directly define life history. Similarly, 'Genetic diversity, mutation rate, and population size' are more related to population genetics, and 'Habitat preference, diet, and migration pattern' are ecological traits.
4. Focus on the option that includes 'Age at first reproduction, frequency of reproduction, and number of offspring per reproductive event.' These variables are directly tied to an organism's reproductive strategy and are central to life history theory.
5. Conclude that the correct answer is the option that includes 'Age at first reproduction, frequency of reproduction, and number of offspring per reproductive event,' as these are the three basic variables that make up the life history of an organism.