Gazelles graze on grass. Cheetahs hunt and eat gazelles.

In an ecosystem where grazers and predators interact, the biomass relationships typically follow the principle of energy transfer within a food web. In this case, gazelles graze on grass, and cheetahs hunt and eat gazelles.

The general expectation in such a scenario would be:

1. Biomass of grass: This would usually be the largest because it is the primary producer. Grass captures energy from the sun through photosynthesis and converts it into biomass.

2. Biomass of gazelles: As herbivores, gazelles depend on the biomass of grass for sustenance. Consequently, their biomass would generally be less than that of grass.

3. Biomass of cheetahs: As predators, cheetahs rely on gazelles for food. The energy transfer from grass to gazelles to cheetahs results in a decrease in biomass at each trophic level due to inefficiencies in energy transfer (approximately 10% of the energy is typically passed from one trophic level to the next).

Given this reasoning, the expected relationship of the biomasses should be:

biomass of grass > biomass of gazelles > biomass of cheetahs.

So the correct response would be:

biomass of grass > biomass of gazelles > biomass of cheetahs.