Answer:
B
Explanation:
The cell membrane is like a gate around the cell, it only lets certain substances come in and out of the cell.
Answer:
<h3>Peripheral nervous system</h3>
The peripheral nervous system (PNS) is divided into the somatic nervous system and the autonomic nervous system. The somatic nervous system (SoNS) is the part of the peripheral nervous system associated with the voluntary control of body movements via skeletal muscles.
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.
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Answer:
B)Photosynthesis releases oxygen into the atmosphere while aerobic respiration removes oxygen from the atmosphere.
Explanation:
Only option B satisfies the answer to the question.
We know that photosynthesis is the process whereby green plants manufacture their foods in the presence of carbon dioxide and sunlight. Carbondioxie in the environment is used to manufacture food in plants. The bye product of photosynthesis is oxygen gas. Oxygen gas is used for aerobic respiration in animals and is essential for their life. This way photosynthesis adds to the pool of oxygen in the atmosphere and aerobic respiration removes from the pool.
