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:
False.
Explanation:
Neuron or nerve cell may be defined as the structural and functional unit of the nervous system. The neurons conduct the nerve impulse and helps in the transmission of signals.
The depolarization of the cell occurs due to the influx of sodium ions into the cell. For the cell membrane to be in resting potential, the potassium ions moves inside the cell from outside the environment and not out of the cell of the organism.
Thus, the correct answer is option (b).
O Cytoplasm
Ribosomes
O Mitochondria
Answer:
Mitochondria
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Pls mark as brainliest
Answer: plastic is the main constituent in the garbage patch found in North Pacific Ocean. It was estimated to be approximately 80 thousand tonnes or about 1.8 trillion pieces of plastic in the patch. A total of 1.8 trillion plastic pieces were estimated to be floating in the patch.
Answer:
Explanation:
Each of the organelles in the cytoplasm of a cell composed of water, proteins and RNA, and whose function is to participate in the synthesis or manufacture of proteins.
Answer:
The Moon's gravity pulls more on the planet than the water on the opposite side. These two water bulges on opposite sides of the Earth aligned with the Moon are the high tides. Since ocean water is pulled higher in the areas of the two high tides, there is less water in between the two high tides.
Explanation:
Answer:
disruptive/diversifying selection
Explanation:
Disruptive (also known as diversifying) selection is a type of natural selection where extreme phenotypic values are more favored rather than intermediate phenotypes. The disruptive selection favors the survivance and reproduction of organisms with extreme phenotypic traits, and in turn impairs the reproduction of organisms with intermediate traits, thereby changing the allele frequencies in the population in order to favor extreme values. An example of disruptive selection is the beak size of Galapagos finches, where extreme phenotypes of this trait have shown to be adaptive according to the type of food found in each island.
The answer is; true
These microbes are usually adapted to their environment and this is why they are found in virtually all ecosystems. You will find bacteria even at the bottom of deep ocean beds deep and in geothermal vents, hypersaline water and very cold regions (such as polar regions). Fungi which vary widely in size from microscopically small to the largest organisms such as mushrooms are also found in virtually all environments on earth. They are nonetheless different species of these groups adapted to their environments.