Five jumbled sentences (labelled 1, 2, 3, 4, and 5), related to a topic, are given below. Four of them can be put together to form a coherent paragraph. Identify the odd sentence out and key in the number of that sentence as your answer.
About half of all the oxygen we breathe is made near the surface of the ocean by phytoplankton that photosynthesize just like land-dwelling plants.
A team of scientists that includes Boston University experts has discovered they also produce oxygen on the seafloor.
The research team used deep-sea chambers that land on the seafloor and enclose the seawater, sediment, polymetallic nodules, and living organisms.
The discovery is a surprise considering oxygen is typically created by plants and organisms with help from the sun—not by rocks on the ocean floor.
The deep-sea rocks, called polymetallic nodules, don’t only host a surprising number of sea critters.
The research team used deep-sea chambers that land on the seafloor and enclose the seawater, sediment, polymetallic nodules, and living organisms.
The correct option is:
"The research team used deep-sea chambers that land on the seafloor and enclose the seawater, sediment, polymetallic nodules, and living organisms."
Step-by-Step Explanation:
To identify the odd sentence out, we need to find the logical connection between four of the five sentences to form a coherent paragraph and see which sentence does not fit into that flow:
1. Establishing the Context (Sentence 1): Sentence 1 introduces the general, well-known fact about ocean oxygen production: "About half of all the oxygen we breathe is made near the surface of the ocean by phytoplankton that photosynthesize just like land-dwelling plants." This sets up the premise that oxygen creation is typically associated with light-driven photosynthesis near the surface.
2. Introducing the Counter-Discovery (Sentence 2): Sentence 2 introduces a contrasting new discovery that challenges the premise in Sentence 1: "A team of scientists that includes Boston University experts has discovered they also produce oxygen on the seafloor."
3. Identifying the Source (Sentence 5): Sentence 5 introduces the deep-sea rocks: "The deep-sea rocks, called polymetallic nodules, don’t only host a surprising number of sea critters." This sentence connects directly to Sentence 2, explaining that these rocks (the "they" referenced in Sentence 2) are responsible for producing oxygen in addition to hosting sea critters.
4. Elaborating on the Surprise (Sentence 4): Sentence 4 concludes the flow by explaining why this is so surprising: "The discovery is a surprise considering oxygen is typically created by plants and organisms with help from the sun—not by rocks on the ocean floor."
Logical Sequence: 1-2-5-4 forms a complete, coherent narrative tracing the traditional view of ocean oxygen production, the new discovery of seafloor oxygen production, the specific rocks involved, and why this discovery is surprising.
Why Sentence 3 is the Odd One Out:
Sentence 3 ("The research team used deep-sea chambers...") describes the experimental methodology and equipment used by the researchers. While it is topically related to the study, it shifts the focus to technical details of the apparatus, which disrupts the conceptual flow of the discovery itself. Therefore, it is the odd sentence out.