instruction:
Given a scientific passage and an answer, generate a question for the given answer.
question:
Passage: Hair, hair follicle, and oil glands. The oil, called sebum, helps to prevent water loss from the skin. The sebaceous gland secretes sebum, which waterproofs the skin and hair. Answer: sebum
answer:
What does the sebaceous gland secrete which waterproofs the skin and hair?

question:
Passage: For example, remember that for the height gene in pea plants there are two possible factors. These factors are alleles. There is a dominant allele for tallness (T) and a recessive allele for shortness (t) . Answer: alleles
answer:
What factors determine the effect of a gene?

question:
Passage: ocean zone in the top 200 meters of water that receives enough sunlight for photosynthesis. Answer: photic zone
answer:
What is the top 200 meters of water in the ocean called?