DNA

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  • Created by: Jenna k
  • Created on: 10-04-14 08:27
What is a Nucleotide?
They are the base units of the nucleic part of DNA.
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What is a nucleotide made up of?
Its made up of Deoxyribose (pentose sugar), phosphate and an organic base.
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Name the four bases.
Thymine, Adenine, Guanine and Cytosine.
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Descirbe the bond between each base pair.
Each pair of bases has hydrogen bonds between them. Thymine and Adenine have 2 hydrogn bonds. Where as Cytosine and Guanine has three hydrogen bonds.
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By what reation does the nucleotide form?
Condensation reation between deoxyribose and phosphate.
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Draw the structure of a nucleotide.
.
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What is a gene
A code for a polypeptide that determines the development and nature of an organism.
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What is the fixed position of a gene called?
The locus
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Explain the triplet code.
to make up an amino acid you need three bases.
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What determines the protein stucture?
The squence of the three bases that determine the amino acid which makes a specific sequence of proteins.
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When is a gene not a code of a polypeptide?
In a eukaryotic cell. Instead they have introns and can occure within genes and as multiple repeats between genes.
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How might mutations in the genes cause a problem?
When there are more than one allele for a gene this can cause a protien to be formed that is non-functional.
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What is the differance in Eukaryotic and Prokaryotic cells.
Eukaryotic have linear DNA and they are asociated with proteins where as Prokaryotic DNA is circular and is not asocciated with proteins.
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What is a Homologous chromosome?
A pari of chromosomes, one maternal and one paternal, that have the same gene loci and therefore determine the same features.
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What is an allele?
One of the different forms of a particular gene.
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Define hapliod.
A cell that contains only one copy of each chromosomes
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Define diploid.
A cell that contains two copies of each chromosomes.
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How is a hapiod formed in meiosis?
The diploid chromosomes are copied so they are homogous. They then split so they are diploid cells. They them split further so the diploids become hapliods.
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What is the process of Meisosis?
Chromosome copied. Line up in cell. chromosomes clump and swap some genes. Cell halves taking one changed chromosome with it. These new cells then halve again and form a hapliod gemete.
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What is the function of meiosis
To roduce genetically disimilar gametes.
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What is Independent segregation?
This is when the two chromosomes line up along side their Homologous partner, which is reandom. The process of separating and which chromosome goes into which cell is independent and is completly random.
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How are gametes genetically different form their parent cell?
When the cells segragates from the parental cell into the dipolid cell, there are two chromosomes which both have the gene for a charactoristic but they both have different alleles. When segregation occures these alleles cane be mixed up.
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Explain genetic recomnination by crossing over.
During the alinement of the homologouse patners they become twisted together. The twisting creates tention which brakes off some of the chromitide. This recombines with the other chromotide and new genetic combinations are formed.
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Other cards in this set

Card 2

Front

What is a nucleotide made up of?

Back

Its made up of Deoxyribose (pentose sugar), phosphate and an organic base.

Card 3

Front

Name the four bases.

Back

Preview of the front of card 3

Card 4

Front

Descirbe the bond between each base pair.

Back

Preview of the front of card 4

Card 5

Front

By what reation does the nucleotide form?

Back

Preview of the front of card 5
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