Chromosomes & KaryotypesWhat is a karyotype?A karyotype is a picture of the complete set of chromosomes in a cell. Scientists examine a karyotype to identify and evaluate the size, shape and number of chromosomes in a human cell. Extra, missing or abnormal positions of chromosome pieces can cause problems with a person’s growth, development and body functions. A normal human male karyotype is represented as 46, XY and a normal female karyotype is represented as 46, XX. Individuals with chromosomal disorders include Down Syndrome (47, XY, +21) and Turner’s Syndrome (45, X) among others.© Copyright NewPath Learning. All Rights Reserved. 94-4422Visit www.newpathlearning.com for Online Learning Resources.Human Karyotype5432161314192021222015161817789101112XX (female)XY (male)orchromosomechromosomesgenegeneDNAstrandChromosomesPairs of chromosomes are found in the nucleus of a cell. One chromosome from each pair is inherited from each parent. Chromosomes are made up of DNA (deoxyribonucleic acid), the hereditary material in humans and most other organisms. The hereditary information in DNA is stored as a code of four nitrogen bases: Adenine, Guanine, Cytosine, and Thymine. Double-stranded DNA has a twisted ladder-like shape called a double helix. Each DNA strand is composed of a series of nucleotides. A nucleotide contains a sugar, phosphate and a nitrogen base.What is a Gene?DNA are called genes. Each gene provides the cell with different information. Each chromosome is made up of many genes. There are about 100,000 genes found on human chromosomes. In each human body cell, there are 46 chromosomes, existing in 23 pairs. One chromosome in each pair is inherited from the mother, and the other from the father. DNA strandnucelotidenucleusGuanineThyminenitrogen basesugarphosphateAdenineCytosinegeneATGCIdentifying Chromosomes 1-3 Very long; centromere in the center 4-5 Very long; centromere not in the center 6-12 Long; centromere not in the center 13-15 Medium; centromere above the center 16-18 Medium; centromere at or close to center 19-20 Short; centromere at or close to center 21-22 Short; centromere not in the centerSex chromosomes X is long; centromere in the center Y is short; centromere above the centerChromosomeCharacteristicsA karyotype is a picture oooffffffffffff tttttttttttttttttthhhhhhhhhhhhhheeeeeeeeeeee coooooommmmmmmmmmmmmmmmmmmmpppppppppppppppplllllete set of chromosooommmmmmmmmmmmmmmeeeeeeeeeessssssssss iiiiiiinnnnnnnnnnnn aaaaaaaaaaaa cccccccccccccceeeeeeeeell. Scientists examine a karyotype to identify and evaluate the size,,,,,,,, ssssshhhhape annnnnnnddddddddddddddddddd nnnnnnnnnnnnnuuuuuuummmbbbbbbbbbbbbeeeeeeeeeeeeeeerrrrrrrrrrrrr oooof chromosomes in aaaaaaaaaaa hhhhhhhhhhhhhhhhuuuuuuuuuuuuuuuummmmman cell. Extra, missing or abnormal positions of chromosome piecesssssssssssss ccccccan cccccccccaaaaaaaaaaauuuuuuuuuuuuuuuusse probbbbbbbbbbblllllllllllleeeeeeeeeeeemmmmmmmmmmmmmmmmmmmsssssss wwiiiiiiiiiiiitttttttttttttthhhhhhhhhhhhhhhhh a person’s growwwwwwwwwwwwwwwwttttttttttthhhhhhhh, development and body functions. AAAAAAAAAAAAAAAAAAAAAAAAAAAA nnnnnnnnnnnnormal human male karyotype is represented as 46, XXXXXXXXXXXXXXXXXYY and a normal female karyotype is represented as 46, XX. Individuals with chromosomal disorders include Down Syndrome (47, XY, +21) and Turner’s Syndrome(45, X) among others.544444444443222222222222221111111166666666666613111131313313113133141919919919999191999111992020202002020220000202221221516166661161616166666181717171777777777777777777789999999999910111111111112XXXXXXXXX (female)XY (male)XXXXXXXXXXXXXXXXXX (female)XY (male)ooorooochromosomechromosssssssssssoooooooooooooommmmmmmmmmmmmmeeeeesgenegeneDNAstrandPairs of chromosomes are found in the nucleus of a cell. One chromosomefrom each pair is inherited from each parent. Chromosomes are made up of DNA (deoxyribonucleic acid), the hereditary material in humans and most other organisms. The hereditary information in DNA is stored as a code of four nitrogen bases: Adenine, Guanine, Cytosine, andThymine. Double-stranded DNA has a twistedladder-like shape called a double helix. Each DNA strand is composed of a series of nucleotides. A nucleotide contains a sugar, r phosphate and a nitrogen base.DDDDDDDDDDDDDNNNNNNNNNNNNNNNNNNNAAAAAAAAAAAAAAAAAAAA aaaaaaaaaaaaaaaarrrrrrrrrrreeeeeeeeeeeeeee cccccccccccaaaaaalled genes. Each genepppppppppppppprrrrrrrrrrrrrooooooooovvvvvvvvvvvvvvvviiiiiddddddddddddddddddeeeeeeeeeeeeeeeess the ceeeeeeeeeelllllllllllllllllllllllllllllll wwwwwwwwwwwwwitttthhhhhhhhhhhhhhhhhhhh dddddddddddddddddiiiiiiiiiiiiifffffffffffffffffffffffffffffeeeeeeeeeeerrrrrrrrrreeeeeeeeeeennt information. EEEEEEEEEEEEaaaaaaaaaaccccccccccchhhhhhhhhhhhhhhhh cccccccccchhhhhhhhhhhhhhhhhhhhrrrrrrrrrrrrrroomosssssssssooooooooooooommmmmmmmmmmmmmmmeeeeee iiiiiiiiiiiiiissssssssssssss mmmmmmmmmmmmmmmmmmaade up of many genes. There are about 100,000 geneeeeeeeeeeesssssssssssssss fffffffffffoooooooooooouuuuuuuuuuuuuuuuunnnnnnnnnnnnnnd on human chromosomes. IIIIIIIIIIIIIIIInnnnnnnnnnnnn eeeeeeeeeeeeeaaaaaaach hhhhuuuuummmmmmmmmaaaaaaannnnnnnn bbbboooooddddddyyyyyyyyyyy cccccccccell, there are 46 chromosomes, eeeeeeeeeeeeeexxxxxxxxxxxxxxxiiiiiiiiiiiiiissssstinnnggggggggggggg iiiiiiiiiiiiinnnnnnnnn 2222222333 pppppaaaaaaaaaaaaaaaaaaiiiiiiiiiirrrssss... OOOOOOOOOOOOOOOOOne chromosome in each pair is iiiiiiiiiiiiinnnnnnnnnnnnnhheriteeeeeddddddddddddddd fffffffffffffrrrrrrrrrroooooooooooooommmmmmmmmmmmmmmmmmm ttttttttttttttttthhhhhhhhhhhhhhhhhhhhhhhhhhe mother, and the other from the father. DNNNNNNNNNNNNAAAAAAAAAAAAAAAA sssssssssstttttttrrrrrrrraaaaaaaaaaannnnnnnnnnnnnndddddddddnucelotidenucelotidenucllllleeeeeeeeeeeeeeeeeuuuuuuuuuuuuuuusssssssssssssGuanineTTTTTTTTThhhhhhhhhhhhyyyyyyyyyyymmmmiiiiiiiinnnnnnnnnnnnnnenitrogen basegsugarrrrrphosphateAdenineCytosssssiiiiiiiiiinnnnnnnnnnnnnnneeeeeeeeeeeeeggggggggggggeeeeennnnnnnnnneeeeeeeeeeeeAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAATTTTTTTTTTTTTTTTTTTTTGGGGGGGGGGGGGGGGGGGGGGCCCCCCCCCCCCCCCCCCCCCCIdentifying Chromosomes 1-3 Very long; centromere in the center; 4-5 Very long; centromere not in the center; 6-12 Long; centromere not in the center; 13-15 Medium; centromere abov;e the center 16-18 Medium; centromere at or close to center; 19-20 Short; centromere at or close to center; 21-22 Short; centromere not in the center;Sex chromosomes X is long; centromere in the center Y is short; centromere above the centerChromosomeCharacteristics
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