Growth Curves and Patterns

We get a growth curve when growth measurements are plotted against set intervals of time. For many whole organisms or parts of organisms, this curve is S shaped and is know. Ad a sigmoid curve. There is an initial lag phase ad the organism prepares to grow. Growth begins slowly as only a small number of cells are involved. It becomes more and more rapid as the number of cells involved becomes larger. Then, there is a steady phase of rapid growth. After  some time, growth starts to slow down and finally comes to a halt. This may be because an organism has reached its maximum size or it may be due to lack of food.

     The growth curve of a unicellular organism, like the amoeba, is also a sigmoid curve. The growth pattern of a population of yeast cells, measured by counting the number of cells or the density of the medium in which they are growing , I'd Aldo a sigmoid curve. Generally, the growth pattern of plants and animals is a basic sigmoid curve with slight modifications.

   Certain pants or organs grow at the same rate as the whole organism. This is called isometric growth. The leaf of a plant shoed this type of growth.

    In animals , organs  grow at a different rate from the  whole organism. This is called allometric growth. In the human, the head and bring develop very rapidly during the earliest stages of life and then stop growing. The rest of the body then grows until adolescence is completed. after which growth in height too ceases.