How did the cell organisms survive if it is so small?

Answer 1

As a cell grows, both its surface area and its volume grow. The surface area is important, as it limits the quantities of oxygen and nutrients the cell can take in, as well as the rate at which it can get rid of waste chemicals. The volume is important, as it contains the organelles that need the chemicals entering the cell and produce the wastes that have to be removed. As the volume increases, more organelles are formed.

With growth in size, the volume grows faster than the surface area. (The volume is measured in cubic units, such as cubic micrometers, whereas the area is measured in square units, so if a cell doubles its width (multiplies it by 2), the volume enlarges by the cube of 2, namely 8, while the surface area increases by only the square of 2, which is 4.) This means that there comes a point at which a cell cannot grow any bigger and still have enough area of surface membrane to supply all its organelles. The organelles in the center of the cell will not receive the necessary chemicals and be able to dispose of their waste products.

To put it more technically, the surface area : volume ratio decreases with increase in cell size, and eventually becomes limiting.

Mature plant cells can grow larger than most animal cells, because the interior of the cell is taken up not by cytoplasm but by a vacuole containing simply water with various chemicals in it. The vacuole contains no organelles.

The rule about surface area : volume ratio applies to any objects of different size, but of identical shape. Any object that become flatter increases the ratio of surface area to volume.

Another advantage of having many small cells is differentiation. The cells become specialized for different functions.

and also large cells won`t fitt in our body if they have large we become fatty people and go into gym and also there will beauties left in human beings

Answer 2

If you mean single celled organisms, they rely on only one cell and the cell has organelles inside of it. The organelles take care of mostly everything; what you eat and breathe contribute to making the organelles work. If you mean the cell itself inside our bodies, they themselves are organisms because they have all the characteristics of life: needs water, needs nutrients, gas exchange, excretes wastes, grows, can die, reproduces, has cells and respond to stimuli. By the way, a cell by itself (as in outside from our bodies), away from the multicellular organism cannot survive. It needs to be within the multicellular orgamism.