Answer:
To build. This building will help people and bring high quality
hope it helps
The onset of menopause will indicate about how many of
immature remains in the ovaries, during middle age, estrogen levels will start
to drop in which egg cells will start to stop to be produced in a female’s body,
the remaining immature egg cells will die.
C. ferns.
Explanation:
The ferns are ancient plants that have managed to survive until the present. They are not closely related to the dominant plants nowadays, the flowering plants, but instead they are closely related with plants that have gone extinct tens and hundreds of millions years ago. Even though the ferns are not the dominant plants, they have managed to find a niche and firmly hold onto it, so they remained widespread, normally occupying the lower layers of the forests.
Unlike the flowering plants that produce flowers and then seeds in order to reproduce, that is not the case with the ferns. The ferns actually reproduce through spores, being widely dispersed by the wind and managing to spread out and reproduce over relatively large territory very quickly.
Answer:
Explanation:
The cell membrane separates the cell from the outer environment. The extracellular fluid contains the sodium ions (Na+), chloride ions (Cl-), while intracellular fluid contains potassium (K +) and negative anions.
The potential difference arises when the membrane is selectively permeable to some ions. The resting potential is -70mV.
When the neurons get excited, the sodium ions start to enter by sodium channels.
Now there are more positive ions inside the cell membrane. It disturbs the resting potential i.e. -70mV. This stage is known as depolarization.
When the inside environment of the cell is more positively charged, the potassium ions start to move out of the cell. It goes out by the voltage-gated channels. Thus resting stage is maintained and it is known as repolarization.
But the initial stability of the cell membrane has to be maintained. To restore the resting stage, the sodium ions start to move out of the membrane and potassium ions enter into the cells again. This is an active transport and has done by the Na+ - K+ pump. Here 3 sodium ions move out and 2 potassium ions pumped into the cell through the plasma membrane.
Thus the resting potential regains. The potassium ions come back into the cells against the concentration gradient and ATP provides the energy for this phenomena.
They are kinda like catalysts