Answer:
They developed from prokaryotic cells that were engulfed by the other cells.
Energy requiring reactions can occur in biological systems because enzymes allow their coupling to other reactions<u> with products of lower free energy than the reactants</u>
Explanation:
Reactions which release energy are exergonic reactions and those that require energy are endergonic reactions. Exergonic reactions are with negative ∆G where the free energy (ability to do a work) of the products is lesser than the free energy of the reactants of the reaction.
To utilize the energy that is released during exergonic reactions, endergonic reactions couple with exergonic reactions in biological systems.
Exergonic reactions are spontaneous and can be coupled with endergonic reactions because their equilibrium constant remains greater than 1.
Cranial nerves arise from the brain and brain stem while the spinal nerves arise from the spinal cord. There are 12 pairs of cranial nerves that pass through the foramine found in the skull and named as CN I to CN XII. 20 bundles of nerve fibers pass through the hole of olfactory foramina and makes the olfactory nerves or Cranial Nerve I (CN I).