The normal membrane potential inside the axon of nerve cells is –70mV, and since this potential can change in nerve cells it is called the resting potential. When a stimulus is applied a brief reversal of the membrane potential, lasting about a millisecond, occurs. This brief reversal is called the action potential
<span>A stimulus can cause the membrane potential to change a little. The voltage-gated ion channels can detect this change, and when the potential reaches –30mV the sodium channels open for 0.5ms. The causes sodium ions to rush in, making the inside of the cell more positive. This phase is referred to as a depolarisation since the normal voltage polarity (negative inside) is reversed (becomes positive inside). </span>
<span>Repolarisation. At a certain point, the depolarisation of the membrane causes the sodium channels to close. As a result the potassium channels open for 0.5ms, causing potassium ions to rush out, making the inside more negative again. Since this restores the original polarity, it is called repolarisation. As the polarity becomes restored, there is a slight ‘overshoot’ in the movement of potassium ions (called hyperpolarisation). The resting membrane potential is restored by the Na+K+ATPase pump.</span>
It helps prevent diarihea, which can be a side effect of taking the antibiotic
<em>Answer</em><em>:</em><em> </em><em>Weathering</em><em> </em><em>and</em><em> </em><em>Erosion</em><em> </em><em>could</em><em> </em><em>make</em><em> </em><em>a</em><em> </em><em>cave</em><em> </em><em>if</em><em> </em><em>the</em><em> </em><em>force</em><em> </em><em>is</em><em> </em><em>high</em><em> </em><em>enough</em><em>,</em><em> </em><em>and</em><em> </em><em>it</em><em> </em><em>would</em><em> </em><em>be</em><em> </em><em>in</em><em> </em><em>the</em><em> </em><em>physical</em><em> </em><em>element</em><em> </em><em>because</em><em> </em><em>chemical</em><em> </em><em>is</em><em> </em><em>not</em><em> </em><em>entirely</em><em> </em><em>correct</em><em>.</em>
<span>Vacuoles are organelles present in plant cells, some animal, and some prokaryotic cells. There is a difference in size between plant and animal cells. Plant cells usually have one large vacuole while animal cells have a number of small vacuoles. If the term "small vacuoles" is used for vacuoles in animal cells, then they are involved in overcoming the foreign particles, storage of waste and during the exocytosis, and invagination of the cell membrane during engulfing the bacteria.</span>
Germ cells are also diploid, but they are found only in the gonads. Gonads are the ovaries in females and testes in males. <span>Gametes are </span>haploid cells<span>, which means that they have only one set of chromosomes. </span>