Genes

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What is a mutation?
A change to genetic material
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What are chromosome mutautions?
A change to the number of or structure of chromosomes
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What are genetic mutations?
A change to DNA
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What are the 2 types of genetic mutations?
Indel and Point
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What are indel mutations?
When nucleotide base/s is inserted or deleted from DNA- this leads to frame-shift
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What are point mutations?
When nucleotide base/s is replaced by another (substitution)
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What are silent mutations (Point)?
When the codon formed codes for the same amino acid
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What are misssense mutations (Point)?
When the codon formed codes for a different amino acid
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What are nonesense mutations (Point)?
When the codon codes for STOP- so the polypeptide chain formed is shorter than it is supposed to be
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What is frame-shift?
Because the genetic code is non-overlapping and read in triplets of 3 bases- if a nucleotide base is inserted or deleted, the amino acid sequence is disrupted
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What does this mean for the protein?
The protein's primary structure is disrupted, and so it's tertiary structure and function is altered.
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What effects can a mutation have?
Beneficial (enhances chances of survival), neutral (no effect to organism) or negative (lowers the chances of survival)
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What are expanding triple nucleotide repeats?
When a gene contains repeating triplets- these increase during meiosis and from generation to generation
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What is the cause of Huntington Disease?
When the expanding triple nucleotide repeats go beyond a critical number
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Why is the transcription of genes regulated?
Not all proteins need to be produced at a constant rate
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In prokaryotes which proteins are needed all the time?
Enzymes that catalyses metabolic reactions
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Which proteins don't need to be synthesised all the time?
Enzymes needed under specific conditions
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What's an operon?
A group of genes that fucntion as a single transcription unit
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What does the bacterium e.coli usually do?
Metabolises glucose
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What happens when glucose is present and a specific disaccharide is present?
When lactose is present (in the absence of glucose), it induces the production of enzymes (Lactose permease + B galactosidase)
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What does the lac operon consist of?
A length of DNA with a regulatory gene, control site (promoter + operator region) and structural genes (lacZ and lacY)
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What does lactose permease do?
Allows lactose to enter the bacterial cell
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What does B-galactosidase do?
Hydrolyses lactose into galactose and glucose
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What are the structural genes?
Lac Z (that codes for B-galactosidase) and Lac Y (that codes for lactose permease)
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Other cards in this set

Card 2

Front

What are chromosome mutautions?

Back

A change to the number of or structure of chromosomes

Card 3

Front

What are genetic mutations?

Back

Preview of the front of card 3

Card 4

Front

What are the 2 types of genetic mutations?

Back

Preview of the front of card 4

Card 5

Front

What are indel mutations?

Back

Preview of the front of card 5
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