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22 Cards in this Set
- Front
- Back
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What does the nucleus do?
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contains genetic material
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What is a gene?
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a short length of a chromosome
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different versions of the same gene are called what?
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alleles
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what is an organisms genotype?
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all of the genes it has
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what is an organisms phenotype?
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all the characterstics it displays
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name 3 structural proteins
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skin, hair and blood
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what is a functional protein
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a protein with a certain function to do something. For example, enzymes are functional proteins because they help with digestion by breaking down food molecules
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why do sperm and egg cells have half the normal amount of DNA
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because its when the sperm cell fertilizes the egg cell that they combine they're chromosomes to make 46.
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why do children resemble both parents, but are identical to neither?
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because children get some of their alleles from each of their parents, although each combination of alleles they have received will be completely unique
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what determines the phenotype?
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the combination of alleles
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what does HOMOzygous mean?
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you have two alleles the same for that paticular gene
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what does HETEROzygous mean?
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you have two different alleles for that particular gene
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genetic testing can be used on what?
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embryos, children and adults
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how is genetic testing used on embryos?
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when embryos are produced using IVF, a doctor can test the embryos to check if they will be born with any genetic disorders. After the embryos are tested, only healthy ones with no disorder are put back into the mothers womb.
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what are the issues surrounding genetic testing?
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1. results may not be 100% accurate.
2. not always 100% safe. 3. if it is positive, should other family members be tested? But some people may prefer not to know? 4. insurance companies may refuse to give life insurance to those with the wrong alleles. 5. Is it right to terminate a pregnancy because of the result? |
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what is a clone?
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a genetically identical organism
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what are stem cells?
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cells that can become other types of cells. They are known as unspecialised
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Describe embryonic stem cells
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stem cells are removed from an embryo and then the embryo is destroyed. They have the potential to turn into any kind of cell at all which makes them exciting for doctors etc.
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describe adult stem cells
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these are found in adult animals. they are involved in maintaining and repairing old and damaged tissues. They can specialise into lots of (but not any) type of cell. No embryos have to be destroyed; they can be removed safely, e.g. by removing bone marrow.
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how can stem cells be used to treat illnesses
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for e.g. - some people with blood diseases can be treated by bone marrow transplants. Bone marrow contains adult stem cells that can then turn into new blood cells to replace and of the old ones that are faulty.
also, embryonic stem cells can be used to replace faulty cells in sick people. Although these are still being researched. |
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How does nature make clones?
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1.by asexual reproduction (where there is only one parent so the offspring are genetically identical to the parent and each other)
2. when cells of an embryo split (identical twins) |
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How do scientists make clones in a lab?
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1. Nucleus of an egg cell is removed - the egg cell now has no genetic information. 2. nucleus from an adult donor cell is inserted in its place. 3. the cell is stimulated, often with an electric shock, and it then starts dividing as if it was a normal embryo. 4. the embryo now produced is genetically identical to the donor cell.
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