Greater portions of the beach begin to appear during ebbing tides, until the maximum amount of beach is visible at low tide. They usually happens twice in a day. Beaches results from wave action by which waves or currents move sand or other loose sediments of which the beach is made as these particles are held in suspension.
Both answers C. and D. are correct. Most marine animals live in pods like seals, whales, and walrus. A. is called a school of fish while B. is a colony of penguins. :(
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.
I would say A) Coevolution because the two species would evolve in response to one another. Flowers and their pollinators must evolve together. For example, if the flower has a mutation that no longer attracts the bumblebees, it will not reproduce. Then the hummingbird would have to find a new food source.
The answer is D, <span>Each daughter molecule contains one DNA strand from the parent molecule.</span>
