Why do the primitive organisms have lesser number of cells as compared to more advanced forms?
Primitive organisms, such as bacteria or single-celled protists, generally have a lesser number of cells compared to more advanced forms of life, like plants or animals. This is primarily because primitive organisms have simple structures and basic functions that can be performed by a single cell, while more advanced forms of life require specialized cells to perform complex functions.
To understand why primitive organisms have fewer cells, we can look at the concept of cell specialization. In more advanced organisms, cells undergo differentiation, which means they specialize into different types to carry out specific functions. For example, in a complex organism like a human, there are nerve cells that transmit signals, muscle cells that allow movement, and blood cells that transport nutrients and oxygen.
In primitive organisms, however, the need for cell specialization is not as significant because they have less complex requirements. For instance, bacteria have a simple cell structure with a cell membrane, genetic material, and basic metabolic machinery. They can carry out all necessary functions, such as obtaining nutrients, replicating their DNA, and reproducing, within a single cell. Similarly, many single-celled protists have structures called organelles that allow them to perform a wide range of functions within a single cell.
Additionally, primitive organisms often have very small sizes, which limits the need for a higher number of cells. Their small size helps in efficient nutrient exchange and simplifies their metabolic needs. By having a smaller number of cells, they can reduce energy expenditure and have a more streamlined and efficient way of carrying out their basic functions.
It's important to note that the number of cells does not necessarily indicate the complexity or advancement of an organism. Primitive organisms have evolved to thrive in their specific environments, and their simplicity can be seen as an adaptation to their specific needs.