I'll try to explain, because I've had tubes before. In fact, I still have them.
For me, tubes were put in because of too many ear infections, and excessive water in my ear. The tube helped drain the water out. You can see A picture I have in a file. The tubes can be put I believe in the ear drum. They're put there to help drain water that has trouble getting out on its own.
Example - the relatively rigid covering of a plant cell, containing cellulose, hemicellulose, lignin, etc.<span>
non example - </span><span>Mycoplasma because it has no cell wall</span>
It is known as a transgenic organism. This procedure is otherwise called "genetic engineering." Genes of one species can be altered, or qualities can be transplanted starting with one animal types then onto the next. Genetic engineering is made conceivable by recombinant DNA innovation. Living beings that have modified genomes are known as transgenic.
Answer:
The cell theory developed most quickly due to the invention of the microscope. Robert Hooke was the first scientist who saw cells in cork. After this discovery, a wide numbered of researches were made and cell theory was developed. The basic cell theory explained that how every living thing was made up of cells. After this, a lot of additions have been made in the cell theory and today the cell theory is known to have five basic postulates.