Modern Genetics

Science, Grade 8

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Human Karyotype © Copyright NewPath Learning. All Rights Reserved. 94-4703 www.newpathlearning.com Modern Genetics chromosome pair T T C G G gene A A A C C C C G G G G T T T A B c D e F G h i J a b C d E f g H I j T A A C G G 1 2 3 6 7 8 9 10 11 12 13 14 19 20 21 22 XX (female) XY (male) 15 16 17 18 4 5 or DNA Fingerprinting Each person has a unique set of DNA. As a result of this uniqueness, it can be used to produce a genetic fingerprint known as DNA fingerprinting. It is a method used by scientists to solve crimes, determine familial relationships or to track hereditary diseases. 1. DNA is extracted from the cell. 2. The extracted DNA is cut into smaller pieces with special enzymes. 3. The DNA pieces are placed on a gel that uses electric current to push them through the gel and separate them according to size. The larger DNA pieces remain closer to the top, while the smaller ones move towards the bottom. 4. The separated DNA pieces on the gel are then stained to reveal their unique banded pattern known as a DNA fingerprint. Chromosomes, Genes and DNA Chromosomes are made up of DNA. DNA, or deoxyribonucleic acid, is the hereditary material in humans and almost all other organisms. The hereditary information in DNA is stored as a code made up of four chemical bases: adenine (A), guanine (G), cytosine (C) and thymine (T). The order, or sequence, of these bases, determines the information available for building and maintaining an organism, similar to the way in which letters of the alphabet appear in a certain order to form words and sentences. DNA bases pair up with each other, A with T and C with G, to form units called base pairs. Each chromosome contains thousands of genes. A gene is a section of a DNA strand that is made up of a series of bases which contains the information for cells to make one specific protein. 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. DNA strand genes proteins chromosomes centromere nucleolus nucleus cell gel electrophoresis system DNA added
\|xiBAHBDy01762sz\ Human Karyotype © Copyright NewPath Learning. All Rights Reserved. 94-4703 www.newpathlearning.com Modern Genetics T T C G G A A A C C C C G G G G T T T J T A A C G G 1 2 3 6 7 8 9 10 11 12 13 14 19 20 21 22 XX (female) XY (male) 15 16 17 18 4 5 or DNA Fingerprinting Each person has a unique set of DNA. As a result of this uniqueness, it can be used to produce a genetic fingerprint known as _____________________________. It is a method used by scientists to solve crimes, determine familial relationships or to track hereditary diseases. Chromosomes, Genes and DNA ___________________ are made up of DNA. DNA, or __________________________, is the __________________________ in humans and almost all other organisms. The hereditary information in DNA is stored as a code made up of four chemical bases: ________________, ________________, ________________ and ________________. The order, or sequence, of these bases, determines the information available for building and maintaining an organism, similar to the way in which letters of the alphabet appear in a certain order to form words and sentences. DNA bases pair up with each other, ___ with T and C with ___, to form units called _______________________. Each chromosome contains thousands of genes. A ________________ is a section of a DNA strand that is made up of a series of bases which contains the information for cells to make one specific ________________. A _________________ is a picture of the complete set of ___________________ 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 _______________ and a normal female karyotype is represented __________________. Individuals with chromosomal disorders include ________________________________ (47, XY, +21) and ________________________________ (45, X) among others. DNA strand nucleolus nucleus cell DNA added gene A B c D e F G h i a b C d E f g H I Key Vocabulary Terms adenine Down syndrome base pairs gel electrophoresis centromere genes chemical bases guanine chromosomes hereditary diseases cytosine karyotype DNA thymine DNA fingerprinting Turner’s syndrome 1. 2. 3. 4. ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ _____________________ _____________________