Indicate if the organisms below are either a photoautotroph, a heterotroph, or a chemoautotroph.

1. A bacterium that uses inorganic H2S as a reducing agent to synthesize carbohydrates from carbon dioxide:

2. A bacterium that can metabolize maltose or glucose, releasing carbon dioxide:

3. A bacterium that uses NH4+ and carbon dioxide to synthesize carbohydrates

1. Haha, this bacterium is a chemoautotroph! It's quite the chemist, using inorganic H2S to whip up some tasty carbohydrates.

2. Ah, this bacterium is definitely a heterotroph, my friend. It prefers to indulge in maltose or glucose to satisfy its carbon dioxide cravings.

3. Now, this bacterium is a photoautotroph. It relies on NH4+ and carbon dioxide to whip up carbohydrates, using the power of sunlight to fuel its culinary pursuits.

1. The organism in question is a chemoautotroph. It uses inorganic H2S as a reducing agent to synthesize carbohydrates from carbon dioxide.

2. The organism described is a heterotroph. It is capable of metabolizing maltose or glucose and releases carbon dioxide as a byproduct.

3. The organism mentioned is a photoautotroph. It uses NH4+ and carbon dioxide to synthesize carbohydrates.

To determine whether the organisms mentioned are photoautotrophs, heterotrophs, or chemoautotrophs, we need to understand the different modes of nutrition in organisms.

1. A bacterium that uses inorganic H2S as a reducing agent to synthesize carbohydrates from carbon dioxide:
This bacterium is a chemoautotroph. Chemoautotrophs obtain their energy by oxidizing inorganic substances and using it to convert carbon dioxide into organic compounds. In this case, the bacterium utilizes H2S as an energy source to produce carbohydrates.

2. A bacterium that can metabolize maltose or glucose, releasing carbon dioxide:
This bacterium is a heterotroph. Heterotrophs obtain their energy by consuming organic compounds produced by other organisms. In this case, the bacterium obtains energy by breaking down maltose or glucose, resulting in the release of carbon dioxide as a byproduct.

3. A bacterium that uses NH4+ and carbon dioxide to synthesize carbohydrates:
This bacterium is a photoautotroph. Photoautotrophs obtain their energy from sunlight through the process of photosynthesis. They combine carbon dioxide with energy obtained from sunlight to synthesize organic molecules. In this case, the bacterium uses NH4+ (ammonium ions) and carbon dioxide, and the energy obtained from sunlight, to synthesize carbohydrates.

In summary:
1. Chemoautotroph
2. Heterotroph
3. Photoautotroph