Unit 1: KA5 The Structure of the Genome Flashcards
What is the genome of an organism?
The entire hereditary information encoded in DNA.
Describe the structure of the genome.
It’s made up of genes and other DNA sequences that do not code for proteins.
What’s a “gene”?
A DNA sequence that codes for a protein.
What does the majority of the eukaryotic genome consist of?
NON-CODING SEQUENCES.
Over 95% of the genome consists of sequences that code for proteins (genes). True or False?
False, less than 2% of the genome consists of sequences that code for proteins.
What is the genome made up of?
Coding sequences called EXONS and non-coding sequences called INTRONS.
What are the 3 functions/roles of the non-coding sequences?
Regulate transcription.
Protection.
Transcribed but never translated.
How do some non-coding sequences act as protection?
Some introns form REPETITIVE SEQUENCES making up a PROTECTIVE STRUCTURE called a TELOMERE at each end of a chromosome.
What’s the function of a “telomere”?
Prevents the chromosome from becoming damaged by fraying at its ends.
Give examples of non-coding sequences that are transcribed but never translated (into proteins).
tRNA and rRNA
You know those two forms of non-translated RNA? What are they able to do?
They’re able to carry out their specific function without being translated into protein.
What’s the function of the coding regions of the genome?
They code for amino acid sequences in protein.
By working out the nucleotide sequence of a genome, it’s possible to describe all the organisms’ genes. True or False?
False
The human genome contains base sequences that regulate transcription. True or False?
True
The human genome doesn’t contain base sequences from which primary transcripts are produced. True or False?
False, it does contain base sequences (exons) from which primary transcripts are produced.
*Exons produce primary transcripts, via transcription, which then code for amino acid sequences in genes.
