What do a pine tree, an octopus, and a bacterium have in common at the cellular level?
Answers
The cells of pine tree and octopus are eukaryotic where as bacteria is a prokaryotic cell. They both are enclosed with a cell membrane filled with cytoplasm. In all the cells, ribosomes are responsible for the protein synthesis. Both the cells have DNA as genetic material.The cells of pine tree and bacteria have cell wall whereas octopus lacks cell wall. The major bio-molecules are carbohydrates, proteins, nucleic acids and lipids in all three cells. The basic mechanism of DNA replication, transcription and translation are same. Major metabolic pathways such as glycolysis and TCA cycle are common. Both the cells have ATP as chemical currency.
Although cells are diverse, all cells have certain parts in common. The parts include a plasma membrane, cytoplasm, ribosomes, and DNA.
The plasma membrane (also called the cell membrane) is a thin coat of lipids that surrounds a cell. It forms the physical boundary between the cell and its environment, so you can think of it as the ‘‘skin’’ of the cell.
Cytoplasm refers to all of the cellular material inside the plasma membrane, other than the nucleus. Cytoplasm is made up of a watery substance called cytosol, and contains other cell structures such as ribosomes.
Ribosomes are structures in the cytoplasm where proteins are made.
DNA is a nucleic acid found in cells. It contains the genetic instructions that cells need to make proteins.
These parts are common to all cells, from organisms as different as bacteria and human beings. How did all known organisms come to have such similar cells? The similarities show that all life on Earth has a common evolutionary history.