The markers and colored buoys serve as the "traffic signals" that direct boats to safety. Lateral navigation markers and non-lateral markers of the US Aid to navigation System must be learned for all operators. A green-lighted buoy marks the border/edge of the channel on the operators' port (left side) as the boat enters from open sea. The odd number 3 signals your direction and distance in returning from open sea( as the number increases).
No they don’t, but to be able to have cellular respiration it can perform aerobic cellular respiration. These cells will move electrons back and forth across their cell membrane. Other types of prokaryotes cannot use oxygen to perform cellular respiration, so they perform anaerobic respiration.
<span>The lymph is moved through the lymphatic vessels by contractions of the lymphatic vessels and the surrounding skeletal muscles.</span>