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29 Cards in this Set
- Front
- Back
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What are genes and where are they found? (2) |
- Instructions to control how an organism develops and functions - Found in the nucleus of cells |
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What do genes consist of? (2) |
- Molecular instructions for a cell that describes how to make proteins - Sections of very long DNA molecules that make up chromosomes in the cells |
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What are proteins? (2) |
- Large organic compounds made of amino acids - Can be structural (collagen) or functional (enzymes like amylase) |
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What can proteins do? (6) |
- Build cells - Move muscles - Fight bacteria and viruses - Carry oxygen in the blood - Speed up chemical reactions in the body (enzymes) - Send chemical messages round the body (hormones) |
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How are characteristics determined? (4) |
- Genetic (Dimples) - Environmental Factors (Scars) - Combination of Both (Weight) - Several Genes working together (eye colour) |
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What do body cells and sex cells contain? (2) |
- Pairs of chromosomes - Sex cells only contain one cell from each pair |
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What are alleles and where are they found? (2) |
- Versions of a gene - In Chromosomes |
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How many alleles does an individual have and what can they be? (2) |
- 2 alleles - Homozygous (DD or dd) or Heterozygous (Dd) |
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What happens during sexual reproduction (genetically)? (1) |
- Genes from both parents come together and produce variation in the offspring |
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Why are siblings similar to their parents but not the same as each other? (2) |
- They receive a combination of maternal and paternal alleles in the zygote - They inherit a different combination of maternal and paternal alleles |
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What can alleles be? (3) |
Dominant (D) and Recessive (d) - one or both dominant alleles will show a dominant trait - one recessive allele will not show the recessive trait - both recessive alleles will show the recessive trait |
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What are the sex chromosomes and how do they make men and women different? (3) |
- XX for women, XY for men - SRY gene on Y chromosomes triggers the development of testes through androgen hormone - Absence of Y chromosomes triggers development of ovaries |
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What is a genotype and phenotype? (2) |
- Genotype: the genetic make-up of an organism (the combination of alleles) - Phenotype: Observable characteristics an organism has |
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What are some disorders caused by? (1) |
- Faulty alleles of a single gene |
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What is Huntingdon's Disease? (3) |
- Genetic disorder cause by dominant allele - Symptoms: Late onset, tremor, clumsiness, memory loss, inability to concentrate, mood changes - No carriers |
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What is Cystic Fibrosis? (3) |
- Genetic disorder caused by recessive allele - Symptoms: Thick mucus, difficulty breathing, chest infections, difficulty in digesting food - One recessive allele will not show symptoms of a disorder, but carrier can pass the allele to children |
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What is False Positive and Negative? |
- False Positive results show the disorder, but do not have it - False Negative results do not show the disorder, but do have it |
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What is an Amniocentesis Test? (4) |
- A needle with a syringe is injected into the womb and takes a sample of amniotic fluid containing fetal cells - Results as 15-18 weeks - 1% change of miscarriage - Very small risk of infection |
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What is a Chorionic Villus? (4) |
- Chorionic Villi (finger-like protrusions of the placenta) are removed for testing - Results at 10-12 weeks - 2% change of miscarriage - Almost no risk of infection |
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What is PGD? (3) |
- Pre-implantation genetic diagnosis - Only for IVF - Test at the 8 cell stage (not yet a fully developed foetus) for genetic disorders |
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What Genetic testing is available for adults? (3) |
- Predictive Testing (Used to detect genetic disorders later in life). People who have no symptoms but family members do - Carrier Testing (Identifying people with recessive allele). People who have no symptoms but family members do - Testing an individual before prescribing drugs |
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What are the implications that need to be considered before testing disorders? (5) |
- Risk in miscarriage (Cell sampling for genetic testing - Using results that aren't accurate (False +/-) - Whether to have children or not - Whether to terminate pregnancy (abortion) - Whether other people should be informed |
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What are problems adults face with genetic disorders? (3) |
- Refused Life Insurance - Refused Mortgages (Not live long enough to pay it back) - Refused Employment (Take time off for being ill) |
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What is asexual reproduction and who can do it? (2) |
- Reproduction that produces offspring that is identical to the single parent - Bacteria, plants and some animals |
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What is a clone and how can they be different? (2) |
- An organism genetically identical to the parent - Only through environmental factors |
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How can clones in plants and animals occur? (3) |
Plants: producing bulbs or runners Animals: - Naturally, when embryo cells spilt (identical twins) - Artificially, when nucleus from adult body cell is transferred into an empty unfertilised egg cell |
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What are stem cells? Give Examples (3) |
A cell that has the ability to differentiate (unspecialised) - Adult stem cells can develop into many but not all type of cells - Embryonic stem cells can develop into all types of cells |
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What are benefits of using unspecialised cells in medicine? (1) |
- Stem cells offer the potential to treat some illnesses (produce organ and tissue which can be transplanted) |
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When do the majority of cells specialise? Which means... (3) |
- During early development of the organism, - Easier to use embryonic stem cells - Adult stem cells are harder to obtain |
