Which Substance Has Not Been Identified as an Electron Donor

question 5

Multiple Choice

Which substance has not been identified as an electron donor in various organisms that carry out either oxygenic or anoxygenic photosynthesis?

• A) Water
• B) Ferrous iron
• C) Sulfide ions
• D) Hydrogen
• E) Carbon dioxide

---

Definitions:

Hashtag Symbol

is a character used on social media to identify or categorize messages on a specific topic, denoted as “#”.

Secondary Research

The process of gathering existing data from previously published sources to conduct a study.

Technical Information

Specialized knowledge or data that pertains to a specific field or technology, usually requiring expertise to understand and apply effectively.

Research Methods

Systematic techniques used for investigating phenomena, acquiring new knowledge, or correcting and integrating previous information.