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

[EX Q]: 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
[EX A]: What does the sebaceous gland secrete which waterproofs the skin and hair?

[EX Q]: Passage: One useful application of PET scanning is in the diagnosis of Alzheimer's disease. This debilitating condition associated with memory loss primarily occurs in elderly individuals. A protein known as beta-amyloid gradually forms deposits, or plaques, in the brain. Severe memory loss and impaired movement appear to be direct results of the plaque growth. Answer: elderly
[EX A]: Alzheimers disease is associated with memory loss in what group of people?

[EX Q]: Passage: Clearing land for agriculture and development is a major cause of habitat destruction. Within the past 100 years, the amount of total land used for agriculture has almost doubled. Land used for grazing cattle has more than doubled. Agriculture alone has cost the United States half of its wetlands ( Figure below ) and almost all of its tallgrass prairies. Native prairie ecosystems, with their thick fertile soils, deep-rooted grasses, diversity of colorful flowers, burrowing prairie dogs, and herds of bison and other animals, have virtually disappeared ( Figure below ). Answer: habitat destruction
[EX A]:
Clearing land for agriculture and development is a major cause of what negative result?