B2

AQA GCSE Science BIOLOGY 2 Unit B2.2 Tissues, organs and organ systems

• Know that the cells of multicellular organisms may differentiate and become adapted for specific functions - specialised cells.

• Know that tissues are aggregations of similar cells and organs are aggregations of tissues performing specific physiological functions eg heart and liver.

• Know that organs are organised into organ systems, which work together to form organisms.

AQA GCSE Science BIOLOGY Unit B2.2.1 Animal organs

• a) Know that large multicellular organisms develop systems for exchanging materials.

  • Know that during the development of a multicellular organism, cells differentiate so that they can perform different functions.

  • The specialised cells form tissues, one or more types of tissue are structured to form organs and two or more organs can work together in an organ system.

  • Bigger multicellular systems e.g. animals like mammals have several different organ systems for absorbing (e.g. gut), transporting (e.g. blood system) and exchanging materials (e.g. lungs).

• You should develop an understanding of size and scale in relation to cells, tissues, organs and organ systems.

• b) Know that a tissue is a group of specialised cells with similar structure and carry out a particular function.

  • Know that examples of tissues include:

    • muscular tissue, which can contract to bring about movement eg contraction and relaxation to move limbs

    • glandular tissue, which can produce and secrete substances such as enzymes to enable chemical reactions and hormones to control certain functional features of an organism,

    • epithelial tissue, which covers some parts of the body including the inside of the gut and the skin.

• c) Know that organs are made of different tissues acting together to perform some particular function.

  • Know that one organ may contain several tissues.

  • Know that the stomach is an organ that contains:

    • muscular tissue, to churn the contents and break up the food into smaller chunks to aid digestion,

    • glandular tissue, to produce digestive juices containing enzymes to break food down at the molecular level,

    • epithelial tissue, to cover the outside and the inside of the stomach.

• d) Know that organ systems are groups of organs that work together to perform a particular function.

  • Know that the digestive system is one example of a system in which humans and other mammals exchange substances with the environment.

    • The digestion process requires a variety of enzymes to breakdown food into soluble products we can absorb from the digestive system, and these enzymes are produced by specialised cells in the glands and gut system.

    • Large…