Higher-level organisation

1.3 Cell division

2.1 Respiratory system

Higher-level organisation

  1. Tissues

    1. A tissue is a group of cells with similar structure and function

    2. Animal tissues

      1. Muscular tissue contract to bring about movement
      2. Glandular tissue produce substances such as enzymes and hormones
      3. Epithelial tissue cover some parts of the body

    3. Plant tissues

      1. Epidermal tissue covers the plant
      2. Palisade mesophyll are packed with chloroplasts to maximise photosynthesis
      3. Spongy mesophyll has air spaces to facilitate diffusion of gases
      4. Xylem & phloem transport substances around the plant

  2. Organs

    1. An organ is a group of tissues, and may contain several types of tissues

    2. An example of an animal organ is the stomach:

      1. It contains muscular tissue to move its contents through the digestive system
      2. It contains glandular tissue to produce digestive juices
      3. It contains epithelial tissue to cover its surface
    3. ####Plant organs

  3. Organ systems

    1. An organ system is a group of organs that perform a particular function

    2. An example of an animal organ system is the digestive system:

      1. It contains glands, such as the pancreas and salivary glands, which produce digestive juices
      2. It contains the stomach and small intestine, which digest food
      3. It contains the liver, which produces bile
      4. It contains the small intestine, which absorbs soluble food
      5. It contains the large intestine, which absorbs water from undigested food, leaving faeces