key area 1.5 - structure of the genome Flashcards
1
Q
what is a gene
A
- sequence of DNA bases that codes for a protein
2
Q
genome
A
- a genome of an organism is its entire hereditary information encoded in DNA (in a full set of chromosomes
- genome is made up of genes (sequences that code for proteins) and other DNA sequences that do not code for proteins (non protein coding regions)
- most of the eukaryotic genome consists of non-coding sequences
3
Q
functions of non-coding sequences
A
- protection : telomeres are protective end caps to chromosomes which stop them unravelling
- regulates transcription by turning genes on and off
- transcription of non translated RNA, some sequences code for tRNA and rRNA (RNA fragments)
- introns within genes
