05/07/2016 · How do single celled organisms work
In the next billion years following the evolution of aerobic photosynthesizing bacteria, the first cells arose which had lost the ability to carry out photosynthesis and thus the ability to manufacture their own food from inorganic material. These cells relied on organic material (other life) as their source of food. The food chain was begun.
Can single celled organisms become cancerous?
Every cell in a multicellular organisms contains all the genes of that organism. However, the genes that are activated vary from cell to cell. The reason we have different types of cells in our body (the cells in your eyes are not the same as the ones that make up your hair) is because different genes are activated in different cells. For example, the gene that produces keratin will be active in hair and nail cells. Keratin is the protein which makes up hair and nails. Genes encode for proteins and the proteins affect the cell’s structure and function so that the cell can specialize. This means cells develop in different ways. This is called differentiation. Differentiation depends on gene expression which is regulated mostly during transcription. It is an advantage for multicellular organisms as cells can differentiate to be more efficient unlike unicellular organisms who have to carry out all of the functions within that one cell.
The evolution of life from its beginning through the development of the metazoa (primitive multicellular organisms) took billions of years. The earth's atmosphere did not contain oxygen when the earth formed 4.6 billion years ago. This reducing environment provided favorable conditions for the natural synthesis of the first organic compounds. The first phospholipid bilayer membranes formed along with primitive RNA and DNA genetic molecules. The membranes adsorbed proteins and the hereditary DNA/RNA material. From these organic molecules, the first primitive prokaryote (simple single cell organism lacking a nucleus) arose. Natural selection began.