Which statement is true regarding axons and dendrites?a) Action potentials travel along the axon. b) The dendrite terminal is the site where neurotransmitters are released into the synaptic cleft. c) Neurons generally possess more axons than dendrites. d) In a neuron, axons typically receive signals, and dendrites typically transmit or send signals.

Action potentials travel along the axon.

Explanation:

Action potential produces in four steps:

(1) Depolarization to the threshold.

(2) Activation of the Na+ channel and rapid depolarization.

(3) Inactivation of Na+ channel and activation of the K+ channel.

(4) Return to normal permeability.

The action potential travels by an unmyelinated axon. Their only 1 segment of the axon affects by the action potential. Then a local current helps to depolarize another segment to the threshold and again cycle repeats.

Another is an action potential travel by a myelinated axon. In this, the current is generated by the action potential and jumps from the node of Ranvier to the next segment.

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.