it requires oxygen, which isn`t always available when he need it
Oxygen is the gas that is required for respiration.
Cellular respiration need oxygen. This oxygen is supplied by external respiration
When oxygen runs out, the muscles and other cells need to obtain energy from oxygen and nutrients. Anaerobic respiration (respiration without oxygen) fills this need.
Cellular respiration can be aerobic and anaerobic. Aerobic respiration requires oxygen, anaerobic respiration does not need oxygen.
For cellular respiration you need oxygen.
a person needs oxygen and glucose for respiration
Nothing! as we are aerobes and need oxygen for respiration.
For respiration you need oxygen and glucose.
Plants need oxygen in order to survive, and is a part of the photosynthesis process. Plants also need carbon dioxide and nitrogen to survive.
Any animal need oxygen for respiration.
Because oxygen is the last electron acceptor