Answer:
A. Cyanobacteria.
Explanation:
Both cyanobacteria and plants use water as an electron donor for the light phase of photosynthesis and make ATP and NADPH. The ATP and NADPH are used in the Calvin cycle to fix the atmospheric CO2 into glucose. The use of water as an electron donor releases oxygen gas as a by-product. This photosynthesis wherein the use of water as an electron donor releases oxygen gas as a by-product is also called oxygenic photosynthesis.
Plant-like protists produce almost one-half of the oxygen on the planet through photosynthesis. Other protists decompose and recycle nutrients that humans need to live. ... Humans use protists for many other reasons: Many protists are also commonly used in medical research
Answer:
IV: Student grade level (6th, 7th, 8th)
DV: "Loudness" (Operationalizing this variable would be beneficial, or in other words, define a way to measure it)
Explanation: