ch 11 Flashcards
what is the open-reading frame?
- stretches of nucleotides that have a reading frame of triplets uninterrupted by a stop codon
homologs (define)
segments of DNA in different species that show evidence of derivations from the same DNA sequence in a common ancestor
what are conserved genes? what can you do with it?
are homologous sequences (tell you that the genes have an important function) found in many different species
-If very similar then your looking at a conserved gene and look at an unknown organism to see if they have similar genes
genomic DNA
-homology drops in more distantly related animals
-Introns can give a lot variability in DNA that does not code for proteins and can drastically chane proteins
protein coding sequences stay high in? effect on evolution?
-vertebrates
-Evolution of protein coding sequences happen slower than others, non-functional DNA sequences
what is cDNA ?
takes RNA converts it into DNA by using reverse trasncriptase
What is the one thing all mRNA should have in common?
poly A-tail
- to selectively separate the mRNA sequences that are not needed
genomic libraries
-All regions of DNA represented (Can make from any tissue; all cells contained the same genome)
-contains introns
-fragments may only contain parts of genes
cDNA libraries
-Only expressed genes are represented (genes that have been transcribed)
-Does not contain introns
-Fragments contain the entire coding regions of a gene
-Alternative splicing may complicate the genomes annotation
what are the two types of repetitive DNA?
-multiple tandem repeats (small repeats that can go very long)
-transposable elements =DNA segments that can more around in the genome
which two repeated segments have function?
-Centromeres: bind proteins that hold sister chromatids together
-telomeres : prevent damaged at the ends of the chromosomes during DNA replication; protects from enzymatic degradation
what affect does exon shuffling have on evolution?
makes new proteins
gene families (define)
are groups of genes that are closely related in sequence and function
when gene families accummilate mutations what affect can that have?what is Psuedogentics?
-diverge and allows the genes to take new specialized but related functions
-Psuedogentics: sequences that looks like genes but do not function as genes
what purpose does bioinformatics serve?
see the meaning of information contains within an organismal system
