Biology 1201A Lecture Notes - Lecture 5: Genome Size, Depurination, Karyotype
9 Apr 2016
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Document Summary
Number of sets of chromosomes in the nucleus of a cell. Karyotype= artificial replication of genome of an organism. Chromosomes don"t actually pair up in the way they appear in picture of karyotype- we take pictures of them during metaphase, stain them and line them up from biggest to smallest. Measure of genome size (count number of bases or measured by mass) The amount of dna in one genome (i. e. one complete set of chromosomes) Characterizes a species (e. g. all humans have the same c-value) Majority of your genome does not code for proteins. Most is junk transposons, dead genes, viruses. Sequence variation: errors in replication, tautomeric shifts, deamination and depurination, radiation. Sequences of nucleotides code for amino acids transcription and translation polypeptide- proteins function as cell structures, communication molecules, enzymes, transporters, etc. Changes in the nucleotide sequence can affect the coded protein, giving rise to different alleles. Change to a structural element of dna sequence.
