Final answer:
Methanotrophs are the bacteria that utilize CH₄ as an electron donor and O₂ as an electron acceptor in cellular respiration.
Step-by-step explanation:
The group of bacteria that use CH₄ as an electron donor and O₂ as an electron acceptor during cellular respiration is called methanotrophs. While methanogens are archaea that produce methane by reducing carbon dioxide, methanotrophs oxidize methane, making them distinctly different and important in the carbon cycle. Methanotrophs are the group of bacteria that use CH₄ as an electron donor and O₂ as an electron acceptor during cellular respiration.