Answer:
antibiotics
Explanation:
pesticides have to do with nature and killing bugs, weeds, etc. Irrigation has to do with watering plants and people. Trucks are vehicles that transport. Antiobiotics help kill bad bacteria in your body when your sick, so that's health related.
The answer is b. Solid Earth
Diffuse modulatory synapses or neuromodulation function different than simple point-to point synapses.
1. Number of postsynaptic neurons
In neuromodulation neuron uses one or more neurotransmitter to regulate several neurons. In Synaptic point-to-point transmission only one particular neuron receives signal from the presynaptic neuron.
2. Neurotransmitter sin neuromodulation (neuromodulators) are not reabsorbed broken down by the pre-synaptic neuron like those in classic synapse. Neuromodulators stay in cerebrospinal fluid.
3. Receptors are also different: the receptors for the neuromodulators are typically G-protein coupled receptors while in classical chemical neurotransmission, they are ligand-gated ion channels.
4. Neuromodulation is a slow process, while classic synaptic transmission occurs fast.