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.
Answer: Plants, animals, and decomposers (which consume dead things) are in a forest ecosystem. Scientists are studying photosynthesis in the forest. Which group or groups of organisms should they study? A jungle ecosystem has plants, animals, and decomposers (which consume dead things).
Explanation:
The right answer is C. thermoregulation and hormone transport.
The cardiovascular system has the function of distributing the blood to the organs.
Blood is a red and slightly viscous liquid that circulates in the blood vessels, propelled by the heart, is essential to the maintenance of life. It transports nutrients, oxygen and hormones to the cells of the body, and rids them of their waste.
Blood circulation helps control body temperature and regulates the volume of certain liquids in the tissues. In addition, the blood carries white blood cells, which defend our body against germs.
Answer:
Benefits:
In a lab, scientists can control the conditions according to their research and study. This allows them to focus on a single perspective.
On the other hand, in a natural setting there are complex interactions due to which focusing on a single attribute can be difficult.
Drawbacks:
Ina laboratory experiment, we cannot control every variable which might be having an effect on our concerned subject as compared to a natural setting. This is because lab experiments are performed in a controlled experiment. Hence, there might be difference of results in a lab experiment and nature.
The Earth's Water Cycle involves Evaporation, Condensation, and Precipitation. Evaporation purifies the water resulting to the replenishment of freshwater to the Earth.
Water pollution is a concern despite of the water being continuously cycled through Earth's systems because the source of pollution is has not been removed.
Water pollution is defined as the contamination of bodies of water. Pollutants are directly or indirectly released to the bodies of water causing the water to be polluted.
Imagine: A river is filled with garbage, it is polluted. The water from the river undergoes the water cycle but since the garbage is still present in the river, the freshwater that comes from precipitation becomes polluted.