i believe it's <u>B. An atom of iron</u>
The two cells of the similar shape, and size have different levels of the ongoing metabolic activity. On one hand, the cell a is metabolically quiet, which means that no energy consuming chemical reactions are taking place in this cell. On the other hand, the cell b is actively consuming the surrounding oxygen. In this scenario, the oxygen will more quickly diffuse into the cell b because the diffusion gradient for oxygen in this cell is steeper than in the cell a.
Hence, the blanks can be filled with 'b and the diffusion gradient is steeper' respectively.
Primary producer type of organism harvests energy to build organic molecules that support animals, fungi, and all the other levels of a food web.
<h3>What is primary producer?</h3>
- The only organisms that can harvest energy from sunlight or chemicals and use it to create food are plants, some algae, and specific bacteria.
- With some plants releasing seeds that only germinate after a fierce fire, the chaparral vegetation is predominately made up of shrubs and is adapted to recurrent fires.
- Autotrophs include algae, plants, certain bacteria, and fungi. Autotrophs are the food chain's producers because they make their own energy and nutrients.
- Like the majority of autotrophs, kelp produces energy through a process known as photosynthesis.
- All fungi are heterotrophic, which means they draw their energy from other living things.
Learn more about organism here:
brainly.com/question/17259533
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