General info

Question 1

general info

Answer 1

• Life began in the ocean as single cells that were surrounded by an infinite aqueous medium supplying their needs
• 2.5 billion years ago there was almost no oxygen in the atmosphere.
• Cyanobacteria were abundant in oceans, obtaining their energy through photosynthesis and producing oxygen which diffused into the atmosphere.
• When organisms developed the ability to use oxygen they could produce energy more efficiently so they could become bigger.
• Mitochondria give cells the ability to use oxygen to produce energy.
• Mitochondria are organisms similar to bacteria that found a way to live inside cells.
• The cells provide the appropriate env for the mitochondria, and the mitochondria helped the cells by producing energy-this is a ‘symbiotic’ relationship.