Life process

• Diffusion is the process used by single celled organisms to carry out basic life processes

  such as gas exchange, etc.
• Carbon based molecules i.e food is used by body from outside to meet it’s energy need.

  Oxygen is used to oxidise food and release energy. So food and oxygen are the basic

  raw materials used by an organism.
• Unlike unicellular,multicellular organisms do not have the cells in direct contact with

  environment. Hence, diffusion cannot meet their oxygen requirements.
• Gas exchange takes place between blood and air in lungs and water and gill tissue in fish
• In plants,gas exchange occurs through stomata present on leaves
• Respiration is the process whereby living things convert food into useful forms of energy
• The respiratory system consists of organs that facilitate breathing and gas exchange
• Multicellular organisms use specialised structures called lungs or gills to take up oxygen
• Respiration is the process whereby glucose reacts with oxygen to produce carbon dioxide and water
• Aerobic respiration requires oxygen and produces more ATP than anaerobic respiration
• Anaerobic respiration does not require oxygen as an input but produces less ATP than aerobic respiration.
• Anaerobic respiration does not require oxygen but only produces two molecules of ATP per glucose molecule.
• Cellular respiration occurs within cells, while photosynthesis takes place in chloroplasts.
• Plants are autotrophs because they can synthesise their own organic compounds using sunlight.
• Aerobic respiration uses oxygen as an input, producing 36-38 molecules of ATP per glucose molecule.
• Photosynthesis uses light energy from the sun to convert carbon dioxide into carbohydrates (glucose) and release oxygen gas.
• Plants are autotrophs because they can make their own food using sunlight, water, and carbon dioxide.
• Photosynthetic bacteria use light energy to convert CO2 into carbohydrates (organic matter).
• Photosynthesis =the process of preparing their own food using water and co2 in the presence of sunlight and chlorophyll
• epidermis= outer layer of the skin,
• stomata is present in the lower epidermis
• exchange of gases takes place in the alveoli of the lungs and the capillaries of the skin
• exchange of gases takes place in stomata, which are tiny pores on the underside of the leaf
• guard cells control the rate of diffusion of water and gases
• green colour plastids contained in leaves are used for photosynthesis and are called chloroplasts
• chlorophyll traps solar energy from sun