What weather conditions produce the brightest red colors?
During the growing season, leaves are green because they contain chlorophyll, a pigment that absorbs sunlight for photosynthesis. Leaves also contain yellow and orange pigments called carotenoids, but the abundant chlorophyll hides them. As days become shorter and temperatures fall in autumn, trees stop producing chlorophyll and the existing supply breaks down. The yellow and orange pigments then become visible. The red and purple colors seen in some leaves come from anthocyanins, which are made in autumn from sugars trapped in the leaf. The brightness of the display depends on the weather: sunny days and cool nights in autumn produce the most vivid reds, whereas a warm, wet autumn tends to produce duller colors.
Answer and explanation
Correct answer: A. Sunny days and cool nights
- Step 1: The last sentence states the conditions. Step 2. Sunny days and cool nights are the best. Answer: sunny days and cool nights. Why not the others: warm, wet autumns give duller colors.
Practise more Academic Passages (Set 2).
Free questions with an explanation for every one, and full timed TOEFL mock tests.
More Academic Passages (Set 2) questions
- What is the passage mainly about?
- According to the passage, what does the length of the waggling run indicate?
- The word 'sophisticated' in the passage is closest in meaning to:
- Why did the researchers move the food sources to new places?
- Which of the following can be inferred from the passage?
- According to the passage, what do coral polyps produce?