Oct 4 Genes and genomes, transposable elements Flashcards
what is the genome?
the entirety of an organism’s hereditary information
usually DNA, but some viruses have RNA genomes
how is double stranded DNA length measured?
measured in base pairs (bp)
100bp=1kbp or kb
1000000bp=1mbp=mb
how is biological complexity related to the size of DNA content in the genome?
it is NOT related
what is the largest sequenced genome?
the australian lungfish xiphophorus, 43Gb (14x human genome)
doesn’t have more genes but has lots of transposable elements
what is a gene?
the entire nucleic acid sequence that is necessary for the synthesis of a functional product (polypeptide or RNA)
can be considered as transcription units
what do exons contain?
the coding region or open reading frame (ORF)
what are control regions?
promoter and cis-regulatory factors
what are introns?
separate the exons
spliced out during mRNA processing
what do proteins with similar functions have?
proteins with similar functions often contain similar amino acid sequences that encode functional domains
how can nucleic acid and protein sequence similarity be found?
BLAST
how does protein number vary among species relative to DNA content?
varies much less
what is the difference in genome size mostly due to?
mostly due to different amounts of non-coding DNA and transposable elements
what are orthologs?
the same protein in different species (alpha tubulin in humans and flies)
what are paralogs?
closely related proteins in the same species (alpha tubulin and beta tubulin in humans)
what are solitary/single copy genes?
protein coding genes that are represented once in the genome
there is only one gene that looks like that, if you do the BLAST search of a protein it makes, there will be no paralogy
what is a gene family?
a set of related genes formed by duplication of an original single copy gene