At what steps should arrows also be drawn in the opposite direction

Which part of cellular respiration must occur before any of the other steps can occur

Greenthe fossil record is the history of life recorded byhuman observationgod. climatologists. remains of the past.

Which part of the neuron below is indicated by the arrow, and what is its function? hormones send chemical signals throughout the body to regulate other body processes. hormones are chemical signals that are sent throughout the body to regulate other body processes. hormones send electrical signals throughout the body to regulate other body processes. hormones are electrical signals that are sent throughout the body to regulate other body processes.