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

[Q]: Passage: For example, in the fall, when the days start to get shorter, the trees sense that there is less sunlight. The plant is stimulated, and it sends messages telling the leaves to change colors and fall. This is an example of photoperiodism , the reaction of organisms, such as plants, to the length of day or night. Photoperiodism is also the reaction of plants to the length of light and dark periods. Many flowering plants sense the length of night, a dark period, as a signal to flower. Each plant has a different photoperiod, or night length. When the plant senses the appropriate length of darkness, resulting in an appropriate length of daylight, it flowers. Flowering plants are classified as long-day plants or short-day plants. Long-day plants flower when the length of daylight exceeds the necessary photoperiod, and short-day plants flower when the day length is shorter than the necessary photoperiod. Long-day plants include carnations, clover, lettuce, wheat, and turnips. Short-day plants include cotton, rice, and sugar cane. Answer: they get shorter
[A]: What happens to the length of the days in the fall?

[Q]: Passage: Horner's syndrome is a condition that presents with changes in one eye, such as pupillary constriction and dropping of eyelids, as well as decreased sweating in the face. Why could a tumor in the thoracic cavity have an effect on these autonomic functions? 32. The cardiovascular center is responsible for regulating the heart and blood vessels through homeostatic mechanisms. What tone does each component of the cardiovascular system have? What connections does the cardiovascular center invoke to keep these two systems in their resting tone? 33. Why does smoking increase the risk of heart disease? Provide two reasons based on autonomic function. Why might topical, cosmetic application of atropine or scopolamine from the belladonna plant not cause fatal poisoning, as would occur with ingestion of the plant?. Answer: one eye
[A]: Which part of the body shows does horner's syndrome affect?

[Q]: Passage: Particulates cause lung diseases. They can also increase the risk of heart disease and the number of asthma attacks. Particulates block sunlight from reaching Earth's surface. This means there is less energy for photosynthesis. Less photosynthesis means that plants and phytoplankton produce less food. This affects whole ecosystems. Answer: asthma attacks
[A]:
Particulates cause lung diseases. they can also increase the risk of heart disease and the number of what?