How do organisms grow and repair themselves?

Organisms grow and repair themselves through a process called cell division.

Cell as per definition is the building block of life, not only in humans but also for all other living organisms. Thus, every cell is important to every form of life in the planet.

During cell division, cells divide themselves and make new cells. When a certain part of the body is damaged, say, you bite your lip accidentally, in a matter of days or so, the wound heals. How? The cells communicate with each other when performing cell division through chemical signals. The new cells formed after cell division replenishes the old cells, thus, healing your wounds faster.

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explanation:

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.