Genes Flashcards
Where are genes located?
On the chromosomes.
Are DNA control sequences always the same?
No, they are protein and tissue specific.
What is an exon?
A coding portion of DNA.
What is an intron?
A non-coding portion of DNA.
What comprises a gene?
Both exons and introns.
Is the whole gene transcribed?
Yes, but introns are removed before translation.
Do both eukaryotes and prokaryotes have introns?
No, only eukaryotes have introns.
Why don’t prokaryotes have introns? Give 2 reasons.
- Smaller genomes = faster replication.
2. Less material to transcribe/translate conserves energy.
Do mitochondria have their own DNA?
Yes.
What are mitochondria evidence of?
Endosymbiosis, they were previously free-living alpha-proteobacteria.
How many mitochondria does each cell contain?
200-100,000.
Is mtDNA associated with proteins like nuclear DNA?
No.
Is mtDNA linear like nuclear DNA?
No, it is circular.
Does mtDNA contain introns?
No (or v. little).
Is the mutation rate of mtDNA higher or lower than that or nuclear DNA?
Higher.
