Biology 0.0 / 5 ? BiologyMicroscopesGCSEAQA Created by: cconroyCreated on: 18-01-19 18:46 What are the 2 types of microscopes? electron and light. 1 of 18 Why is an electron miscroscope better than a light microscope? because and electron microscope passes electrons, rather than light. 2 of 18 What is the formula for magnification? magnification=size of image/size of real object. 3 of 18 What is one stage of mitosis? When the cell divides into 2 identical cells. 4 of 18 What does each chromosone carry? hundreds to thousands of genes. 5 of 18 how many chromosones does a human have? 46, 26 pairs. 6 of 18 What is a stem cell? an undifferentiated cell - they have not become specialised. 7 of 18 What are stem cells from human embryos called? embryonic cells. 8 of 18 What is an embryonic cell? Can make all different types of cells. 9 of 18 Where are stem cells mainly used? where cells are damaged or not working properly. 10 of 18 What is theraputic cloning? where a cloned embryo of the paitient may be made and used as a source of stem cells. 11 of 18 Why is it important that the chromosones are copied before mitosis occurs? because daughter cells are needed. 12 of 18 What is diffusion? net movement of particales from an area of higher concentration to an area of lower concentration. 13 of 18 Why does this happen? becuase the particales move randomley and spread out. 14 of 18 What is osmosis? the diffusion of water from a dilute situation to a concentrated solution thorugh a partially permeable membrane. 15 of 18 What is active transport? moves subtances against a concentration gradient, from an area of low concentration to high. 16 of 18 What active transport require for this to happen? energy, from respiration. 17 of 18 What does active transport allow? mineral ions to be absored into plant root hairs. 18 of 18
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