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Zorluk: OrtaEvaluating the Impact of New Evidence

### Deep-Sea Bioluminescence

Deep-sea octocorals of the genus *Metallogorgia* emit a blue-green light when physically disturbed. Two hypotheses have been proposed to explain the source of this bioluminescence.

Hypothesis 1
The bioluminescence is produced endogenously by the octocoral itself. The octocoral’s cells synthesize a specific eukaryotic luciferase enzyme and its corresponding luciferin substrate.

Hypothesis 2
The bioluminescence is produced symbiotically. The octocoral houses populations of bioluminescent bacteria belonging to the genus *Vibrio* in extracellular chambers, and the light is generated through prokaryotic enzymatic pathways.

New Evidence
Researchers isolated a novel compound, peptidomycin, from the tissue of *Metallogorgia*. In controlled trials, peptidomycin was shown to selectively inhibit prokaryotic protein synthesis, causing the death of bacteria, while having no effect on eukaryotic protein translation or cellular metabolism.

How does the discovery of peptidomycin in active bioluminescent tissues affect the proposed hypotheses?

  1. A
    It weakens Hypothesis 1 and supports Hypothesis 2.
  2. B
    It weakens both Hypothesis 1 and Hypothesis 2.
  3. It supports Hypothesis 1 and weakens Hypothesis 2.Cevap
  4. D
    It supports both Hypothesis 1 and Hypothesis 2.

Cevap

The new evidence supports Hypothesis 1 and weakens Hypothesis 2.
The correct answer is that the new evidence supports Hypothesis 1 and weakens Hypothesis 2. Peptidomycin is an antibacterial compound that inhibits prokaryotic translation and kills bacteria, which directly undermines the premise of Hypothesis 2 that the bioluminescence is bacterial in origin. Because peptidomycin does not affect eukaryotic translation, the octocoral's own cells remain unaffected, supporting the endogenous mechanism proposed by Hypothesis 1.

Adım Adım Çözüm

1
Analyze the mechanism of the new evidence, peptidomycin.
Peptidomycin selectively kills prokaryotes (bacteria) by inhibiting prokaryotic translation, but has no effect on eukaryotes (the host octocoral).
To determine how the compound interacts with the organisms proposed in each hypothesis.
2
Evaluate the impact of peptidomycin on Hypothesis 2 (symbiotic bacteria).
Since peptidomycin kills bacteria, symbiotic bacteria would not survive or function in the tissue of active bioluminescent octocorals, which weakens Hypothesis 2.
To assess if the bacterial explanation remains viable given the presence of the antibacterial compound.
3
Evaluate the impact of peptidomycin on Hypothesis 1 (endogenous production).
Since peptidomycin does not affect eukaryotic protein translation or metabolism, the octocoral's eukaryotic pathways remain fully functional, which is consistent with and supports Hypothesis 1.
To assess if the host-only explanation is supported by the tolerance to the compound.

Anahtar Kavram

Evaluating how new evidence affects competing scientific hypotheses by analyzing biological mechanisms and their implications.
Tahmini Süre:1m 30s
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Evaluating the Impact of New Evidence

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