Modern genetics

by hafiz m Waseem university of education Lahore

1. MODERN GENETICS HAFIZ M WASEEM UNIVERSITY OF EDUCATION LAHORE

2. Context Introduction Definition Structure of DNA Central dogma DNA replication Transcription Translation Mutation Genegic engineering Medical Genetics research

3. MODERN GENETICS What Is Genetics? The study of gene ,heredity,variation ,and mchanism of heredity from one generation to next generation. Inheritance Classicla Genetics Based on visible results of reproductive acts. It is basically the mendlian Genetics Modern Genetics . The modern genetics is the study of DNA and how it serves as the molecular basis of heredity.

4. MODERN GENETICS DEFINITION “That body of Method and analysis that percieve genetics as the study of economy of nucleic acid and associated compound.” Modern genetics  focuses on the chemical substance that  genes  are made of, called deoxyribonucleic acid, or DNA, and the ways in which it affects the chemical reactions that constitute the living processes within the cell.

5. MODERN GENETICS Why Mendle is clled the father of modern gendtics ? Modern genetics began with the work of the   Augustinian friar   Gregor Johann Mendel . His work on pea plants, published in 1866, established the theory of Mendlian inheritance. Mendel work suggested that heredity was not acquired . He proposed that “Each trait is control by particles he called them unit factor Now it is known as gene. But t he importance of Mendel’s work does not gain understanding until 1900 after his death

6. Modern Genetics . The modern genetics is the study of DNA and how it serves as the molecular basis of heredity begans 1920s it became clear that chromosome contained gene for genetics trait. A number of experiment were important in establishing that DNA was the genetic material of living organisms. Mendel “unit of inhertance” Gene Chromosome Nucliec Acid

7. Modern Genetics A number of experiment were important in establishing DNA was indeed the genetic material of living orgnism _ Griffith Experiment(1928) _ Harshey and chase experiment (1952) _Griffith Experiment(1928) Griffith was studying two strain of bacteria streptococcus pneumoniae which cause pneumonia and other factor infection smooth strain (s) Rough strain (R):

8. Griffith Experiment Griffith concluded that the genetic instruction had been transferred to rough bacteria from dead smooth bacteria . He called this the process of Transformation

9. _ Harshey and chase experiment (1952) They proofed that DNA Rather than protein carry the heredity information of life EcoliBactaria : Bactariophage is a virus that infect bactaria only contain a protein coat capsid and DNA carried the genetic instruction to make more viruses protein capsid : labelled with Radioactive Sulphur s35 _DNA : labelled with radioactive phosphorus p38 Bacterial cells that are infected with the two types Bactariophage and examine labeled viral protein did not enter into infected bactaria While labeled viral DNA did enter into infected Bactaria so it is concluded that, DNA Is the molecule that carries the genetic information to make new viruses

10. Nucleic Acid DNA(Heredity material ) DNA was discovered in 1869 by Swiss researcher  Friedrich Miescher The three-dimensional structure of DNA, first proposed by James D. Watson and Francis H. C. Crick in 1953, consists of two long helical strands that are coiled around a common axis to form a double helix DNA Nucloetide

11. Nucleic Acid RNA Ribonucleic acid is a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes Types of RNA There are three types of RNA: mRNA , tRNA , and rRNA . mRNA is the intermediary between the nucleus, where the DNA lives, and the cytoplasm, where proteins are made. rRNA and tRNA are involved in protein synthesis. Additional RNAs are involved in gene regulation and mRNA degradation.

12. Central Dogma DNA Replication The first step of central dogma is DNA replication It is a process in which DNA produce its copy in which one strand is new and other is old as it conserved in new molecule and thus DNA replication is said to be semiconservative.

13. Central dogma Transcription: Transfer of the genetic message from DNA to mRNA . The genetic information are not translated directly into protein but first is transcribed into messenger RNA Transcription involve numerous enzyme that unwind a region of a DNA molecule ,initiate and mRNA synthesize and modify the mRNA after transcription is complete . Unlike DNA only one or few genes are exposed and only one of two DNA strand s transcribe. DNA unwind and RNA is made by reading the DNA template.  DNA serves as a template for the synthesis of mRNA from RNA nucleotides in the nucleus.

14. Central dogma The process of protein formation from mRNA is called translation mRNA molecules carrying a specific code determined by the base sequence of the DNA template move from the nucleus to the cytoplasm. Strands of mRNA carrying codons transcribed from DNA, move the ribosomes in the cytoplasm. Codon : a triplet in a DNA molecule  . Triplet : grouping of three nitrogenous bases in DNA or RNA molecules Different triplets of nitrogenous bases in tRNA molecules pick up specific amino acids in the cytoplasm and carry them to mRNA at the ribosomes Amino acids are put into position on the ribosome with instructions from the triplet codes of tRNA and mRNA. With the aid of enzymes and ATP (energy), the amino acids are bonded to form a polypeptide chain (protein) on the ribosom

15. Mutation A mutation is a change in a DNA sequence. Mutations can result from DNA copying mistakes made during cell division, exposure to ionizing radiation, exposure to chemicals called mutagens, or infection by viruses. Germ line mutations occur in the eggs and sperm and can be passed on to offspring, while somatic mutations occur in body cells and are not passed on.

16. Type of Mutation Micro mutations :it is also called point mutation Macro mutations Numerical Aberration Aneuploidy Euploidy Structural Aberration Deletion Duplication Inversion Insertion Translication  

17. Genetic engineering T he group of applied techniques of genetics and biotechnology used to cut up and join together genetic material and especially DNA from one or more species of ocharacteristics Cultivating plant and breeding domestic animals Selective breeding Gene manuplation Cloning Recombinent DNA

18. Recombinent DNA Recombinant DNA , molecules of DNA from two differen species that are inserted into a host organism to produce new genetic combinations that are of value to  science , medicine, agriculture, and industry. Steps Isolation of the  Gene  of Interest ( DNA  Sequence) -  Gene  Therapy. Insertion of the Isolated  Gene  into a Vector. Selection of Transformed Host Cells. Expression of the  Gene  introduced into the host.

19. Medical Genetic Research Screening :Analysis of body fluid Genetic counseling Karyotyping Gene therapy Gene therapy  is an experimental technique that uses  genes  to treat or prevent disease. 

20. References   Griffiths AJ, Miller JH, Suzuki DT, Lewontin RC, Gelbart, eds. (2000).  "Genetics and the Organism: Introduction" . An Introduction to Genetic Analysis (7th ed.). New York: W.H. Freeman.  ISBN   978-0-7167-3520-5 . ^  Hartl D, Jones E (2005) ^   "the definition of genetics" . www.dictionary.com. Retrieved 25 October 2018. ^   "Genetikos ( γενετ - ικός )" . Henry George Liddell, Robert Scott, A Greek-English Lexicon. Perseus Digital Library, Tufts University.  Archived  from the original on 15 June 2010.   Griffiths AJ, Miller JH, Suzuki DT, Lewontin RC, Gel bart,