<span>This hyperpolarization is due to the exiting of potassium ions or the influx of chloride ions through the channels in the neuron. During this time, the neuron enters a refractory period (approximately 2ms), during which an action potential is unable to be transmitted. After this timeframe, the neuron resets to around -70mV and the cell becomes able to re-transmit an action potential.</span>
The correct answer is an immunologist.
Reaction to peanut such as itchiness, trouble in swallowing and breathing are the signs of peanut allergies.
It is descried as type I hypersensitivity (reexposure to antigen-allergen) reaction of the immune system in susceptible individuals. So, diseases that affect immune system such as allergies are concern of an immunologist.
The best answer is C.
The outermost covering of plant cells is called the cell wall. It is made up cellulose, is rigid and can be seen under a light microscope. It is absent in animal cells.
The outermost covering in animal cells is the cell membrane. It is made up of lipids, proteins, and small amounts of carbohydrates. It is a thin and delicate structure that can only be seen under an electron microscope.
Plant cells have both cell wall and cell membrane
When a cell is differentiated that means it is no longer a ''blank canvas'', a pluripotent cell (like the stem cells).
Let's take a muscle cell as an example.
Before it is differentiated, it is just like all of the other stem cells.
But after the expression of genes specific for muscle cell and the resulting changes in structure and physiology of the cell, this cell becomes a muscle cell.
Afterward, the differentiated muscle cell communicates integrates with other muscle cells into the muscle tissue. The muscle tissue eventually forms organs like skeletal muscles, the heart and similar.
<span>The situation shown consists of a picture with the sun emitting light energy; and a plant both absorbing carbon dioxide and emitting oxygen. The missing reactant in order for photosynthesis occur is water. Plants absorb water from the soil (through roots) and absorbs ligth energy from the sun (through leaves). The energy absorbed is used to split water molecules into H2 and O2. Then H2 combines with CO2 to form glucose. The answer is the option A) water.</span>