Numerical answer
Four sentences related to a common theme are given below. Three of them can be logically combined to form a coherent paragraph. Identify the sentence that does NOT fit and key in its number as your answer.
1. Coral reefs cover a small fraction of the ocean floor yet support a disproportionate share of marine biodiversity.
2. This outsized productivity depends on a delicate symbiosis between coral polyps and the algae living within their tissues.
3. Deep-sea trenches, by contrast, host organisms adapted to crushing pressure and permanent darkness.
4. When ocean temperatures rise, this symbiosis breaks down, causing the corals to expel their algae in the phenomenon known as bleaching.
1. Coral reefs cover a small fraction of the ocean floor yet support a disproportionate share of marine biodiversity.
2. This outsized productivity depends on a delicate symbiosis between coral polyps and the algae living within their tissues.
3. Deep-sea trenches, by contrast, host organisms adapted to crushing pressure and permanent darkness.
4. When ocean temperatures rise, this symbiosis breaks down, causing the corals to expel their algae in the phenomenon known as bleaching.
Show answer and solution
Answer: 3
Sentences 1, 2 and 4 form a coherent thread about coral reefs: their biodiversity (1), the symbiosis underlying it (2), and what disrupts that symbiosis (4). Sentence 3 shifts the topic entirely to deep-sea trenches, an unrelated ecosystem, and does not connect to the coral-reef thread — it is the odd one out.
Saved on this device. Sign in or create a free account to keep it on every device.