Banu's blog for school students

ORGANELLES IN A CELL   There are several structures scattered in cytoplasm of a cell. These are called as organelles which performs different functions in cell. Mitochondria is one such organelle which is very important as it is involved in respiration of a cell.  STRUCTURE OF MITOCHONDRIA  Mitochondria ( singular: mitochondria) are small, spherical or cylindrical organelles. The number of mitochondria in a cell depends upon the functions it performs. Cells with heavy energy demands, such as muscle cells, have more mitochondria than other cells. Generally a mitochondrion is 2-8 micron long and about 0.5 micron wide. It is about 150 times smaller than the nucleus. There are about 100 to 150 mitochondria in each cell.  When seen under the compound microscope ,the mitochondria appears oval or cylindrical dots in the cell.  When seen under the electron microscope, the mitochondria seems to have a double membrane wall. Their outer membrane is smooth whereaa inner mem...

Every living organism is made up of small  basic  units called 'cell'. A cell is called as a basic structural and functional unit of an organism. The cells are the building blocks of a body. The size of a cell is very very small starting from 0.5 microns to 1 micron . The smallest cell is a bacterial cell which is 0.5 micron whereas the biggest cell is an ostrich egg cell which is 18cm×17cm.  Every cell has its own particular structures called organelles which are very very important because each carry out their own specific function. A typical cell consists of the following organelles: NUCLEUS: The central dark black color spot present in the cell is called nucleus.  It is also called as "CONTROL ROOM OF THE CELL".  It has all genetic material which can be either DNA or RNA . This genetic material is responsible for passing the characters from parents to children. The nucleus is also involved in cell division. CYTOPLASM: The fluid present inside the cell which ...