The Main Blood Vessels The pulmonary and systemic circulations are features of a double circulatory system, where blood passes through the heart twice in one full circuit around the body The pulmon...
Closed Double Circulatory System The need for a circulatory system The cells of all living organisms need a constant supply of reactants for metabolism, e.g. oxygen and glucose Single celled organi...
Phloem: Mass Flow The Mass Flow Hypothesis was the model initially used to explain the movement of assimilates in the phloem tissue The mass flow hypothesis was modelled by Ernst Münch in 1930. His...
The Sucrose Loading Mechanism Assimilates such as sucrose are transported from source to sink through the phloem sieve tubes Carbohydrates are generally transported in plants in the form of sucrose...
Movement in the Phloem Although translocation could refer to the transport of substances in the xylem and phloem, as it means ‘moving from one place to another,’ it is more commonly connected with ...
Xerophytic Plant Leaf Adaptations Xerophytes (from the Greek xero for ‘dry’) are plants that are adapted to dry and arid conditions Xerophytes have physiological and structural (xeromorphic) adapta...
Water & the Transpiration Pull The movement of water Water has unique properties it is polar hydrogen bonds form between the water molecules Water moves from the roots to the leaves because of ...
Transpiration Explained The movement of water through a plants xylem is largely due to the evaporation of water vapour from the leaves and the cohesive and adhesive properties exhibited by water mo...
Water & Mineral Ion Transport: Pathways & Mechanisms Within a plant mineral ions and organic compounds (eg. sucrose) are transported by being dissolved in water. The dissolved mineral ions ...
