Question

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explique cómo este experimento prueba la hipótesis. hipótesis de ejemplo: si el alimento misterioso es tofu, entonces reaccionará con el reactivo que indica la presencia de una proteína porque el tofu es principalmente proteína. ¿qué tubo(s) de ensayo actúan como control negativo? dropdown options: gelatina, agua, muestra de comida misteriosa, tanto agua como gelatina

Explanation:

To answer the question about which test tube acts as a negative control, we analyze the options:

A negative control in an experiment is a group/condition where the expected result is negative (i.e., the substance being tested for is absent). In a protein - detection experiment:

• Agua (Water): Water contains no protein. So, if we test water with a protein - detecting reagent, it should show no positive reaction (a negative result), making it a suitable negative control.
• Gelatina (Gelatin): Gelatin is a protein - rich substance. Testing it would likely give a positive result for protein, so it is not a negative control.
• Muestra de comida misteriosa (Mysterious food sample): This is the sample we are testing (the experimental group), not a control.
• Tanto agua como gelatina (Both water and gelatin): Gelatin is a protein source, so this mixture would not act as a pure negative control.

Answer:

A. agua (Water) acts as the negative control because it lacks protein, so the protein - detecting reagent should show no positive reaction (a negative result), validating the experiment’s setup.