A multicellular fungus grows through damp leaf litter. Dissolved substances enter its cells by diffusion across its outer surface. Four possible growth forms are described.
Which growth form would allow diffusion to supply its cells most effectively without an internal transport system?
one large spherical mass containing all the fungal cells
one broad, thick sheet with cells stacked in many layers
many thin threads packed together into one dense bundle
many thin threads spread separately through the leaf litter
102 exam-style questions on Edexcel GCSE Biology 8.1 Exchange surfaces and diffusion, covering 8.1.1 Introduction to exchange and transport, 8.1.2 Alveoli adapted for gas exchange, 8.1.3 Factors affecting rate of diffusion, and 8.1.4 Rate of diffusion using Fick's law. Each one has a worked solution and a mark scheme showing where the marks go.