Multicellular organisms have cells that are specialised to carry out different functions. They are functionally and structurally distinct.Their shapes and number of organelles are related to their function.Cells contain varying amount of organelles and the organelles may be adapted to their function.For example many mitochondria in a cell indicates that the cell is metabolically very active and requires a lot of energy. The mitochondria may be more dense and have more numerous cristae.
A fertilised egg is called a zygote. The zygote undergoes mitosis and develops into an embryo.The first three divisions yield 8 identical cells. Each cell can develop into a complete organism.The cells continue to divided by mitosis. As they do so, different genes are switched on and off in each type of cell. resulting in different cells.Each cell contains the same genes but a different set of genes is expressed in each type of cell. As a result the cells become differentiated and each type of cell is structurally and functionally different from any other type of cell.There are 216 different types of cell in the human body.
A fertilised egg is called a zygote. The zygote undergoes mitosis and develops into an embryo.The first three divisions yield 8 identical cells. Each cell can develop into a complete organism.The cells continue to divided by mitosis. As they do so, different genes are switched on and off in each type of cell. resulting in different cells.Each cell contains the same genes but a different set of genes is expressed in each type of cell. As a result the cells become differentiated and each type of cell is structurally and functionally different from any other type of cell.There are 216 different types of cell in the human body.