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HUMAN BIOLOGY - Evidence of evolution > Mutations > Flashcards

Flashcards in Mutations Deck (18)
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1

Population

a group of organisms of the same species living together in a particular place at a particular time

2

Gene pool

The sum of all the alleles in a given population

3

Allele frequencies

how often each allele of a gene occurs in the gene pool for that population

4

Mutation

A change in a gene or a chromosome leading to a new characteristic in an organism - a permanent change in the DNA.

5

Mutant

A characteristics resulting from a mutation

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Two types of Mutations

Chromosome; when all or part of a chromosome is affected.

Gene mutation; Changes in a single gene so that traits normally produced by that genes are changed or destroyed.

7

Mutagenic agents

Known to increase the rate of which mutations occur. E.g. X-rays, mustard gas etc.

8

Gene mutations

A change in the bases of the DNA could change the amino acid and could alter the protein. Could have no affect or prevent the protein from being produced.

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Types of mutation

Induced; a mutation caused by a mutagenic agent

Spontaneous; A mutation that occurs due to an error in the natural biological process

10

Heritability of the mutation

Somatic; A change occurring in the gene in the body cell.

Germline; a change in the heredity material in the egg or sperm that becomes incorporated into the DNA of every cell in the body

11

Effects of Mutation

Missense Mutation; A change in the amino acid and therefore the protein that is produced

Non-sense Mutation; A change in the base sequence that results in a STOP of the code. Therefore synthesis will stop and shorter proteins are produced.

Neural Mutation; A mutation that causes a change in the amino acid, however does not cause a change in the overall protein produced

Silent Mutation; A mutation that does not change the sequence of the amino acid

12

Extent of mutations

Chromosomes mutations affect a whole number of genes whereas Gene mutations only affect a singular gene.

13

Change in DNA (Nucleotide)

1. insertion - A new nucleotide is added to the DNA strand
2. Substitution - An existing nucleotide is replaced with another
3. Deletion - A nucleotide is removed from the DNA strand

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Point mutations

A change in just one of the bases in a DNA molecule

15

Frame shift mutation

Occurs when bases have been added or removed. This results in a series of bases that codes for an amino acid starting at a different base. They affect the outcome for all the DNA from that point on.

16

Change in DNA (DNA strands)

1. Duplication - a section of chromosome occurs twice
2. Deletion - A piece of DNA is removed
3. Inversion - Breaks occur in the Chromosome and is rejoined the wrong way around
4. Translocation - part of the chromosome breaks off and is rejoined to the wrong chromosome
5. Non-disjunction - During meiosis, a chromosome part does not separate and so one daughter has an extra chromosome and one daughter has one less chromosome

17

Conditions due to mutations (Gene)

Gene mutations;
1. Duchenne Muscular dystrophy
2. Cystic fibrosis

18

Conditions due to mutations (Chromosomal)

Chromosol mutations;
1. Down syndrome or trisomy 21.
2. Partial trisomy
3. Patau syndrome