What is the shape of the Cocci bacteria?

With reference to glucose metabolism and cellular respiration, consider the following statements:
Statement 1: The conversion of succinate to fumarate in the TCA cycle is unique because it is the only step catalyzed by an enzyme embedded in the inner mitochondrial membrane and directly links the TCA cycle to the electron transport chain.
Statement 2: Oxidative phosphorylation is the only stage of cellular respiration where oxygen is directly consumed, and all ATP generated in this stage is produced by substrate-level phosphorylation.
Statement 3: In glycolysis, the enzyme phosphofructokinase-1 (PFK-1) is allosterically inhibited by high concentrations of ATP and citrate, making it a key regulatory point for both glycolysis and the TCA cycle.
Which of the statements given above are correct?

In the Z-scheme of photosynthesis, which of the following electron flow combinations are NOT correct?

(i) P680 → Pheo → PQA → PQB → Cyt b6f → PC → P700

(ii) P700 → A0 → A1 → FeSx → FeSA → FeSB → Fd

(iii) P680 → Pheo → PQA → PQB → Cyt b6f → PC → P700

(iv) P700 → FA → A0 → FeSA → FeSB → FeSx → Fd

Which scientist worked independently and reached a similar conclusion to Darwin's?