<span>A. A ventral, solid nerve cord.
</span>some have it solid but most of them have a Hollow one.
Answer:Estuaries
Explanation:
Estuaries are areas where freshwater streams or rivers merge with the ocean. This mixing of waters with such different salt concentrations creates a very interesting and unique ecosystem
Complete question:
Receptors trigger one of two effector pathways resulting in changes in neuronal activity. These changes will, ultimately, effect gene expression. Which effector pathway is characterized by ion flux through transmitter-activated channels resulting in an altered membrane potential and neuronal activity?
A. Slow effector pathways
B. Modulated effector pathways
C. Rapid effector pathways
D. NMDA glutamate receptor pathways
Answer:
D. NMDA glutamate receptor pathways
Explanation:
The NMDA glutamatergic receptor is a cationic channel receptor modulated by a ligand that allows the transport of Na+, K+, and Ca2+. Under certain situations, it exhibits particular permeability to Ca2+. The receptor has different regions that are susceptible to modulation by endogenous and exogenous agents. The receptor can be found at most excitatory synapses, where it responds to the neurotransmitter glutamate. During synapsis, the presynaptic membrane releases L-glutamate, which is received by NMDA glutamatergic receptor. The receptor plays a regulatory role because activates signaling cascades that depend on calcium.
These receptors are involved in normal synaptic transmission, in a diverse physiological phenomenon, and might be responsible for neurodegenerative processes.
