<span>These are some distinguished areas in ecosystems that help the humans immensely. Floodplain is area that lies low and is subjected to floods in regular periods making it reduce intensity of floods and improving the stability of the soil. This also improves water quality and ground water making the ecosystem suitable for flora and fauna. Meander unlike floodplain is a broad valley like which is with time develops with bends and helps the ecosystem by reducing the speed of river flow. Delta is the region that is formed around the vast water bodies because of the water flow or the lack of it. It helps the ecosystem by giving protection from natural calamities like floods and hurricanes.</span>
The B. hippocampus is the part of the central nervous system that helps students remember the correct answers.
The hippocampus is primarily associated with memory, but it is also thought to be the center of emotions and the autonomic nervous system.
Explanation:
the body regulates glucose levels through the pancreas. the pancreas secretes insulin, which in turn regulate glucose levels..
I believe the correct order is:
D - A nerve signal arrives at an axon terminal;
B - Voltage gated calcium channels open and calcium enters the cell;
C - ACh is released and diffuses across the axon terminal;
E - Ligand gated sodium channels open and sodium enters the cell.
A - A postsynaptic potential is produced;
Explanation:
The dendrites of the presynaptic neurons receive a signal. The signal stimulates the nucleus of the presynaptic neuron to produce an electrical signal that is managed by the axon hillock. the axon hillock again manages and transmits the nerve impulse into the axon towards the axon terminal. The signal is transmitted via saltatory conduction on myelinated axons for faster communication. When the nerve impulse reaches the axon terminal, it causes opening of voltage gated calcium ion channels. This will cause an influx of calcium ions into the presynaptic axon terminal. The influx of calcium ions then stimulates the synaptic vessicles in the presynaptic membrane that contain the neurotransmitter acetylcholine (ACh) to move towards the presynaptic membrane. They then fuse with the membrane and open up releasing all their acetylcholine into the synaptic cleft (space between presynaptic membrane and post synaptic membrane). The ACh will bind to ligand ion channels on post synaptic membrane causing opening of sodium channels and there is an influx of sodium inside the post synaptic membrane producing a membrane potential. The voltage gated calcium ion channels in the presynaptic membrane will then close and no more ACh is released. The cells then return to rest. The acetylcholine in the postsynaptic neuron is either broken down by the enzyme acetylcholinesterase into metabolites that are used by the cell or they are removed as waste into the surrounding glial cells called astrocytes that nourish neurons. They (ACh) also can be stored for future use by the post synaptic neuron.
Level: High School
Subject: Biology
Topic: The nervous system
The solute is the substance dissolved in water.
A hypotonic solution is a solution with a low concentration of solute.
A hypertonic solution is a solution with a high concentration of solute.
An isotonic solution is a solution that contains equal concentrations of solutes.
The direction of water displacement (or osmosis) depends on the total concentration of solute on each side of the membrane and not the nature of the solute.
