Cell structure

• MRSGREN stands for movement, reproduction, sensitivity, growth, respiration, excretion, nutrition.
• A good light microscope can achieve a magnification if 400, a good electron microscope can achieve a magnification of 40,000
• Plant cell walls are made of cellulose.
• Fully permeable means it will let all substances through, partially permeable means it will only let some substances through.
• Cell membranes are partially permeable
• The main constituent of cytoplasm is water
• A vacuole is a space in a cell, surrounded by membrane and containing solution.
• Cell sap is a solution of sugar and other substances
• You would find chloroplasts in a plant cell
• The nucleus stores inherited information (DNA)
• 1 millimetre is 1/1000 of a metre, 1 micrometre is 1/1000 of a millimetre, 1 nanometre is a 1/1000 of a micrometre.
• Image size = Actual size × Magnification

  Actual size = Image size ÷ Magnification

  Magnification= Image size ÷ Actual size

  
• Cells are the smallest structure and functional unit of an organism, which is typically microscopic and consists of cytoplasm and a nucleus enclosed in a membrane.
• Tissues are a group of similar cells which together perform a particular function
• Organs are part of an organism; a structure made of several tissue ls, which performs a particular function e.g. heart.
• Organ systems are a structure of made of several organs working together, which performs a particular function e.g. digestive
• An organism is a form of life considered as a unit e.g. animal, plant, fungus, or bacteria