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15 Cards in this Set
- Front
- Back
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Why does sexual reproduction cause variation? |
When gametes fuse, one of each pair of alleles comes from each parent |
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What are the female sex chromosomes? |
XX |
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What are the male sex chromosomes? |
XY |
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What are different foprms of one gene called? |
Alleles |
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What is a dominant allele? |
Only one copy is needed to pass on the trait |
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What is a recessive allele? |
The trait will only be passed on if two recessive ones are present |
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What are chromosomes made up of? |
Large molecules of DNA (deoxyribo nucleic acid), which has a double helix structure |
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What is a gene? |
A small section of DNA |
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What does each gene do? |
Each gene codes for a particular combination of amino acids, which make a specific protein |
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As each person has unique DNA, how can people be identified? |
DNA fingerprinting - This excludes identical twins |
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How are some disorders caused? |
Some disorders are inherited |
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What is Polydactyl(y)? |
Polydactyl(y) is a disorder that causes extra fingers or toes |
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How is Polydactyl(y) passed on? |
It is caused by a dominant allele of a gene, so can be passed on if one parent has the disorder |
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How can Cystic Fibrosis be ingerited |
Cystic Fibrosis is a recessive gene, so both parents must be heterozygous or have the disorder |
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How can genetic disorders be predicted? |
Embryos can be screened for the alleles that cause them |
