Growth and Development of different organisms National 5 Biology Key Area 6: The Need for Transport (a) Plant Transport Systems National 4 Biology Key Area 4 Growth and Development of different organisms

Learning Outcomes for Topic 6 – Part A Explain why plants need a transport system Name the 2 transport systems in plants Give the function of each of the 2 plant transport system Be able to identify 7 structures in a leaf State the function of each structure State what is meant by ‘transpiration’ Describe the process of transpiration in a plant

oxygen for respiration removal of poisonous waste products The need for transport All cells need the same basic things... oxygen for respiration glucose removal of poisonous waste products

Transport in unicellular organisms oxygen poisonous waste products glucose Substances move into the cell by diffusion. This is effective because the cell has a large surface area relative to volume.

Transport in multicellular organisms The body’s surface area is small in relation to volume Cells are too far from the “absorbing” organs Transport system is needed to deliver substances to all body cells Don’t forgot that plants are also multicellular organisms. Let’s have a look at how they are organised ... Absorbing animal organs – lungs and small intestines. Absorbing plant organs – leaves and roots

Level of organisation in Multicellular Organisms

Think/pair/share What does a plant need from the soil? What transport system carries this? In what direction? What does a plant make in the leaves?

Plant Transport Systems

Plant Transport CROSS-SECTION

Plant Transport Systems Plants have two systems for the transportation of substances: Xylem transports water and mineral salts from the roots to the leaves. Phloem transports sugar up and down the plant.

XYLEM TISSUE PHLOEM TISSUE Dead hollow tube Companion cell Sieve plate Cytoplasmic strands Sieve tube = the whole thing! Dead Hollow tubes containing lignin Xylem cells are lignified to withstand the pressure changes as water moves through a plant (this stops them bursting) Living tissue Sieve tube with a companion cell. Sugar is transported up and down the plant through cytoplasmic strands.

Xylem vessel Under a microscope

Investigating Water transport in a plant

Investigating Water transport in a plant

Investigating Water transport in a plant

Investigating Water transport in a plant