Final answer:
The use of both organic and inorganic carbon forms is called mixotrophy, and the term for photosynthesis by bacteria using water as the electron donor is oxygenic photosynthesis.
Step-by-step explanation:
The simultaneous use of both organic and inorganic forms of carbon is referred to as mixotrophy. This strategy, indicating an organism's ability to adapt to varying environmental nutrient availability, allows for the assimilation of carbon in multiple forms to support growth and energy requirements.
Mixotrophs are versatile as they can combine autotrophic and heterotrophic means of nutrition depending on the resources available to them.
In reference to photosynthesis performed by bacteria using water as the electron donor, the correct term is oxygenic photosynthesis.
This process leads to the release of oxygen as a by-product, distinguishing it from anoxygenic photosynthesis, where electron donors other than water are used and oxygen is not produced.