BTEC Applied Science Unit

What is the name of the process by which cells become specialized for a particular function from stem cells - differentiation Explain what tissues are - a collection of specialized cells Explain what an organ is - a collection of tissues performing specific physiological functions what is the difference between to ribosomes in a prokaryote and a eukaryotic cell - prokaryotes - 70s ribosome eukaryote - 80s ribosome Describe the function of the nucleolus - Produces ribosomes and RNA Describe the function of the cell wall - Provides rigidity and protection to the cell Describe the function of the chloroplasts - Site of photosynthesis as they contain chlorophyll Describe the function of the plasmodesmata - A channel through the cell wall the allows transport of materials from one cell to another Describe the function of the amyloplasts - Stores starch and converts starch back into glucose when the plant needs energy Describe the function of the vacuole - Stores water and chemicals for cell use. Also maintains turgor of cell Describe the function of the tonoplasts - Membrane the surrounds the vacuole. Protects the vacuole, isolates it from harmful substances and controls water flow in and out of the vacuole Why are gram positive bacteria more susceptible to antibiotics? - Permeable cell wall whereas gram negative bacteria have a semi-permeable cell wall Describe the adaptations found in a palisade cell - Closely packed together Chloroplasts Large vacuole Explain why the palisade cell has a large number of chloroplasts - To absorb lots of light for photosynthesis Explain why palisade cells are closely packed together - To form a continuous layer in the leaf Explain why palisade cells have a large vacuole - To maintain turgor (pushes against the cell wall to maintain rigid shape) Describe the adaptations of a root hair cell - Root hair shape Large vacuole Thin cellulose walls Cell membrane channels mitochondria