Energy-requiring reactions can occur in biological systems because they can be coupled with reactions that are:, a. spontaneous and endergonic.
b. not spontaneous.
c. exergonic.
d. endergonic.
e. unlikely.

Can happen anywhere along the spine if the neural tube does not close all the way. the backbone that protects the spinal cord does not form and close as it should. this often results in damage to the spinal cord and nerves. a) cleft palate b) spina bifida c) encephalocele d) down's syndrome