Genes&Society_1 Colour slide perpage_Lecture2

Di this represents a compression of more than 100000

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Unformatted text preview: Genetics>Amazing Genetics>Amazing Cell Cell Must See Learn Genetics: Tour of the basics 28 Eukaryotic Eukaryotic Cell, Nucleus, Chromosome, DNA The 2-meter length DNA must be packaged into a nucleus that is about 5 2micrometers in diameter. di This represents a compression of more than 100,000! ~40 miles thread 29 into a tennis ball. Getting to know some terms: A chromosome is a package of some genetic material. chromosome is package of some genetic material 1 chromosome = 1 very long DNA molecule • An eukaryotic chromosome is consist of a long linear DNA molecule wrap up and coil around certain packaging proteins (eg. histones). • A prokaryotic chromosome is usually circular ‘naked’ DNA without wrapping and coiling to histones (although may be associated with other proteins). • On the chromosome are found many genes. the chromosome are found many genes A prokaryotic cell usually has one chromosome. An eukaryotic cell usually has more than one chromosome and are usually in pairs (e.g. human has 46 chromosomes or 23 pairs of chromosomes) A Gene is a fundamental physical unit of heredity which contains all of the information require to produce a single polypeptide product. 1 gene = a short sequence of DNA (with specific characteristics) found on gene the chromosome. A Genome is the entire genetic make-up or all the genetic information carried makeby a cell or required to ‘make’ the organism. A genome is consist of30 all DNA (all genes) on all the chromosomes. Packing Packing DNA: How to fit a whale into a bathtub? • The 2-meter length DNA must 2be be packaged into a nucleus that is about 5 micrometers in diameter. • This represents a compression of more than 100,000! ~40 miles thread into a tennis ball. • It is made possible by wrapping the DNA around protein spools called nucleosomes and then packing these in helical filaments packing these in helical filaments • Chromatin, the nucleoprotein complex, consists of histones and non histone chromosomal of histones and non-histone chromosomal proteins proteins 31 See See IVLE animation 32 Scale Scale in “Mapping” (All the countries = the whole genome = all genetic information) (that make the organism; includes all the chromosomes) chromosomes) Contain many genes Complete...
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This note was uploaded on 03/21/2013 for the course GEK 1527 taught by Professor Tan during the Winter '11 term at National University of Singapore.

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