The answer to this question is <span>membrane potential
The gradient of electrolyte concentration from inside cell and outside cell will determine the membrane potential. Natrium or sodium is much higher outside the cell than inside cell. In contrast to the sodium, potassium is much more inside cells. This two electrolyte have major role in the membrane potential and action potential. </span>
There are holes in the end of the phloem tubes because Phloem consists of sieve tube cells and companion cells for conduction of food These sieve elements are placed end to end . At the the junction of two sieve elements there is a plate called sieve plates having circular pores.
Stamen is composed of anther and filament. The pistil is composed of stigma, style, and ovary. ... The key difference between stamen and pistil is that stamen is the male reproductive organ which produces pollens of angiosperms while pistil is the female reproductive organ which produces ovules of angiosperms.
I hop this helps!
