Answer:
The correct answer will be option-B.
Explanation:
A neurotransmitter is a chemical messenger used by the nerve cells to transmit the signals from one neuron to another neuron and muscle cell at the synaptic cleft. The common neurotransmitter is acetylcholine, dopamine, serotonin and others.
The neurotransmitter can be excitatory that is causing the generation of the action potential in the neurons or inhibitory that is prevent the generation of neuron in neuron cell. This depends on the receptors to it binds.
The neurotransmitters can be degraded or can be taken back after the work is completed. thus, Option-B is the correct answer.
Answer:
Cellular membranes or plasma membranes has many functions. Some of these include regulation of cellular transport, and responding to cellular signals or hormones.
<h2>Cellular Transport</h2>
The plasma membrane is made up of the <u>phospholipid bilayer with embedded transmembrane proteins</u>. This makes the cell membrane <u>semi-permeable</u>. Movements of substances depend on the composition of the molecules e.g. glucose and amino acids, as needed by the pancreatic cells. These are larger and uncharged molecules and can't pass freely through the membrane so they utilize the transmembrane proteins via attaching to carrier proteins. This is called <em>passive transport</em>. On the other hand, in <em>active transport</em>, <u>ATP is used</u> to transfer molecules, like Hydrogen, from a low to high electrochemical gradient.
Other kinds of cellular transport are:
- Osmosis and diffusion
- Endocytosis
- Exocytosis
<h2>Cellular Signalling</h2>
The cell membrane is able to signal other neighboring cells by utilizing complex proteins. These proteins may take form as receptors or markers.
<h3>Membrane Receptors</h3>
They act as receivers of extracellular signals and spark intracellular processes. These receive signals from hormones, growth factors, etc.
<h3>
Membrane Markers </h3>
These allow the cells to identify each other and respond if this cell is needs further development as in organ development, or a foreign body to the system.
Phases of meiosis<span>. In many ways, </span>meiosis<span> is a lot like mitosis. ... Since cell division occurs twice during </span>meiosis<span>, one starting cell can produce four gametes (eggs or sperm). In each round of division, cells go through four </span>stages<span>: </span>prophase<span>, metaphase, anaphase, and telophase.</span>
Expression of how a given product.
