Examples
None required Yes
All plants and animals
Cigarette smoke Tea Bag Perfume
Uptake of glucose in intestine
5 Explain how the surface area to volume ration affects the rate of movement of substances into and out of cells.
A small cell has a large SA:V ratio and therefore can exchange molecules with it's external environment rapidly. However, ions and water can be lost by diffusion and osmosis, and heat can be lost at a faster rate.
A large cell has a small SA:V ratio and therefore exchanges molecules with it's external environment slowly. Large cells are less efficient as often they cannot obtain enough oxygen and nutrients for their needs.
3. Plants and animals have specialized structures to obtain nutrients from their environment. 1 Identify some examples that demonstrate the structural and functional relationships between cells, tissues, organs and organ systems in multicellular organisms . Multicellular organisms (tree)
Organ Systems (transport system, xylem)
Organs (leaf)
Tissues (phloem tissue)
Cells (guard