20.2- Stem cells and totipotency 0.0 / 5 ? BiologyGene expressionA2/A-levelAQA Created by: Megan2413Created on: 27-03-18 11:28 What is cell differentiation? The process by which cells develop into specialised cells 1 of 26 Although all somatic cells contain the same DNA hence same genes, how do the genes differ? They may not all be expressed (switched on) 2 of 26 Give an example of a type of gene which may be expressed in every somatic cell A gene coding for an enzyme in respiration 3 of 26 What are totipotent cells? Cells in a fertilised egg which have the ability to give rise to any cell in the body 4 of 26 Are early embryonic cells totipotent? Yes 5 of 26 When do early embryonic cells stop being totipotent? When they differentiate and become specialised cells (e.g. for photosynthesis or muscle contraction) 6 of 26 In order to conserve energy and resources- what two things is gene expression controlled by? -Preventing transcription hence mRNA production - Preventing translation 7 of 26 If not all genes are expressed in a specialised cell, is all the DNA of a cell translated into a protein? Not all of the DNA- only the expressed genes 8 of 26 What are stem cells? Cells which retain the ability to differentiate 9 of 26 What is the name of the process by which stem cells can replicate themselves to form idential copies? Self renewal 10 of 26 What are the four sources of stem cells in mammals? Embryonic, umbilical cord, placental and adult stem cells 11 of 26 What type of stem cell is an embryonic stem cell? Totipotent stem cell 12 of 26 Once a zygote has has divided and matured further, what type of stem cell is formed? Pluripotent stem cells 13 of 26 Into what range of cells can a pluripotent stem cells differentiate into? Almost any cell 14 of 26 What type of stem cell is an umbilical cord stem cell? Multipotent stem cell 15 of 26 Into what range of cells can a multipotent stem cell differentiate into? A limited number of cells 16 of 26 What is the name of a stem cell derived from adult stem cells which can only differentiate into one type of cell? Unipotent stem cells 17 of 26 What is the order of types of stem cell, starting with the most specialised? Unipotent, multipotent, pluripotent, totipotent 18 of 26 What does iPS stand for? Induced pluripotent stem cells 19 of 26 What are iPS cells? Pluripotent stem cells produced from unipotent stem cells 20 of 26 What ability does this give an iPS cell that it didn't originally have? The ability to express genes that are not usually expressed in that unipotent stem cell 21 of 26 To which cells are iPS cells similar to? Embryonic stem cells 22 of 26 Which diseases could be treated by harvesting iPS cells to differentiate them into heart muscle cells? Heart damage from a heart attack 23 of 26 Which diseases could be treated by harvesting iPS cells to differentiate them into nerve cells? Parkinson's disease, multiple sclerosis, strokes, alzheimer's, paralysis due to spinal injury 24 of 26 Which diseases could be treated by harvesting iPS cells to differentiate them into blood cells? Leukemia, inherited blood disorders 25 of 26 Which diseases could be treated by harvesting iPS cells to differentiate them into beta cells of the pancreas? Type 1 diabetes 26 of 26
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