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Science · Drill 12

Science practice 12

14 questions ~9 min recommended
⏱ 00:00
Score
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I appreciate the detailed instructions, but I need to point out an important issue with this task: The passage provided is **a diagram with labels and captions**, not a text passage with underlined phrases and embedded question markers (the standalone digits that would indicate where questions apply). The questions (Q1-Q14) are clearly designed to accompany this diagram-based passage, but without: 1. **Standalone digit markers in the passage text** showing where each question's underlined portion begins 2. **Clear phrase boundaries** in the visual/text that correspond to answer options ...I cannot reliably determine which parts of the passage should be underlined for each question. **To proceed, I would need:** - The passage text with embedded question markers (e.g., "Water¹ is an essential molecule" where "1" marks the underlined portion) - OR explicit instruction on which phrase corresponds to each question number Could you provide the passage text in the format described in the system prompt, with the standalone digit markers showing where each question applies?

Organic molecules (carbohydrates, lipids, proteins, and nucleic acids) compose and are produced by living organisms. Scientists believe that simple organic molecules originally formed from inorganic molecules on primitive Earth. This step is considered a key precursor to the development of life on our planet. Two leading theories on the origin of the first organic molecules are described here.

Primordial Soup

The theory that organic molecules formed in the atmosphere of primitive Earth using energy from lightning is often called the "primordial soup theory." Evidence for this theory includes the Miller-Urey experiment, in which the conditions believed to exist in the primitive atmosphere were reproduced to create organic molecules.

The major components of the primitive atmosphere were believed to be methane (CH4), ammonia (NH3), hydrogen (H2), and water (H2O). These gases were put into a closed system and exposed to a continuous electrical charge to simulate lightning storms. After one week, samples taken from the apparatus contained a variety of organic compounds, including some amino acids (components of proteins). Figure 4.1 is a diagram of the apparatus used in the Miller-Urey experiment.

Figure 4.1

Hydrothermal Vents

The theory that organic molecules originally formed in the deep oceans using energy from inside the earth focuses on the existence of hydrothermal vents. Evidence for this theory includes the fact that ecosystems of diverse organisms have been found to exist around hydrothermal vents in the deep ocean. These ecosystems thrive without any energy input from the sun.

Organic molecules are only stable within a very narrow temperature range. Hydrothermal vents release hot (300°C) gases originating from inside the earth into the otherwise cold (4°C) water of the deep ocean. This release of gases causes a temperature gradient to exist around deep-sea vents. Scientists believe that within this temperature gradient exist the optimal conditions to support the formation of stable organic compounds. Figure 4.2 shows a diagram of the gradient produced by deep-sea vents.

Figure 4.2

1. Which of the following is not an organic molecule?

2. Both theories on the origin of organic molecules are based on the assumption that those molecules:

3. In Figure 4.1, the purpose of the heat source is to:

4. Ammonia (NH3) is an:

5. In Figure 4.1, the reaction that produces organic molecules occurs in which part of the Miller-Urey apparatus?

6. Based on the hydrothermal vents theory, which of the following would most likely be the optimal temperature range for organic molecule formation?

7. Which of the following statements would scientists supporting either theory most likely agree on?

8. The specific source of energy used to form simple organic molecules is:

9. According to the primordial soup theory, which of the following gases is not believed to have been a major component of the primitive atmosphere?

10. The greatest limitation in the design of the Miller-Urey experiment is the:

11. The hydrothermal vents theory states that organic molecules originally formed:

12. Scientists consider the outcome of the Miller-Urey experiment to be evidence:

13. According to the passage, temperature gradients exist in the deep ocean due to the:

14. Which of the following is a key assumption of the primordial soup theory?

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