Genomes, Transcriptomes, Proteomes Flashcards
1
Q
What is a genome?
A
- The sum of the genetic information contained within an organism
- Influences nearly every character of an organism
- Give insight into evolution: chimpanzees and humans share 98% of genome
2
Q
Where is the genome found in eukaryotes?
A
In chromosomes in the:
- Nucleus
- Mitochondria
- Chloroplasts
3
Q
How does genome size differ between organisms?
A
- Genomes of simple organisms are small and dense
- More complex organisms have more DNA, more genes and more untranslated regions
- Genome size goes up with body size
4
Q
Why does genome size differ with body size?
A
- In small organisms their genetic machinery is expansive compared to the rest of the organism
- Thus the genetic material has to be economised
- Therefore there are fewer, more compact genes
- In larger organisms the number of genes goes up but density goes down
5
Q
What information can be gained from genomes?
A
Mitochondrial Genome
- Genome evolves quickly
- Polymerase not as effective so makes more mistakes
- Site of respiration so lots of oxidative stress which causes mutations
- Can be used for short term evolutionary studies
Nuclear Genome
- Evolves more slowly
- Can be used for long term evolutionary studies
- Same genes present in different species can be compared
- Can understand gene function
6
Q
What is a telomere?
A
- A series of repeats where the microfibres attach to pull to different pole
- Get shorter as you age
- Main reason for again as cannot undergo mitosis any more
7
Q
How is a nuclear genome organised?
A
- Centromere in the middle
- Surrounded by satellite DNA
- Telomeres at ends
Zoom - Transposable element
- Intergenic region
- Regulatory sequence
- Transcribed region
- Regulatory sequence
8
Q
What is in a mammalian chromosome
A
- Repetitive DNA
- Ribosomal DNA
- Telomeres
- Centromeres
- Up to 98% of DNA sequences are untranscribed
- Natural selection would retain important information
9
Q
What are mini satellites?
A
300bp sequences that are repeated
10
Q
What are micro satellites?
A
2-3bp units which are repeated
11
Q
What are transposable elements?
A
- Code for enzymes recognise their own DNA sequence
- Cut them out and move them to another part of the chromosome
- Can move other genes with them
12
Q
What is a point substitution mutation?
A
- One base change
- Change in amino acid
- If in the third codon position likely won’t make a difference
- If in the first codon position change is almost certain
13
Q
What is an insertion mutation?
A
- Extra bases inserted
- Frame shift
- Gene will probably be switched off
14
Q
What is a deletion mutation?
A
- One base deleted
- Frame shift
15
Q
What is PCR
A
- Polymerase Chain Reaction
- Allows production of any amount of a known DNA sequence
