Thomas Engelmann illuminated a filament of algae with light that passed through a prism, thus exposing different segments of the algal filament to different wavelength of light. He added aerobic bacteria and found that these bacteria congregated in the area illuminated by red and blue light. If you ran the same experiment without passing light through a prism, what would you predict ?

Options

A. There would be no difference in results
B. The number of bacteria would decrease along the entire length of the filament
C. The bacteria would be relatively evenly distributed along the length of the filament
D. The number of bacteria would increase along the entire length of the filament

Answer

To answer the question regarding Thomas Engelmann's experiment without using a prism, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Engelmann's Original Experiment**: Engelmann illuminated a filament of algae with light that was separated into different wavelengths using a prism. He observed that aerobic bacteria congregated in areas illuminated by red and blue light, indicating that these wavelengths were more effective for photosynthesis.

2. **Consider the Effect of Using White Light**: If the experiment is conducted without a prism, the filament of algae would be illuminated with white light, which contains all visible wavelengths combined.

3. **Predict the Distribution of Bacteria**: Since the white light is not separated into its component colors, the entire filament would receive a mix of all wavelengths of light. The bacteria, which were attracted to areas of higher photosynthetic activity (red and blue light), would not have specific areas of attraction in this setup.

4. **Conclusion on Bacterial Distribution**: Therefore, in the absence of the prism, we would expect the bacteria to be relatively evenly distributed along the length of the filament because there would be no specific areas of higher photosynthetic activity (as seen with red and blue light).

5. **Final Prediction**: The prediction is that the bacteria would be relatively evenly distributed along the length of the filament when illuminated with white light.