Tiêu đề Moleculer basis of inheritance.pdf ✅

XII CLASS CBQ : CONCEPT BASED QUESTIONS CRTQ : CLASS ROOM TEACHING QUESTIONS SPQ : STUDENT PRACTICE QUESTIONS PREVIOUS YEAR QUESTIONS SEPARATE BOOK-LET (2016-2022) BOTANY No. of Volumes - 2 SNO. TOPIC NAME VOL 1 REPRODUCTION IN ORGANISMS 2. SEXUAL REPRODUCTION IN FLOWERING PLANTS 3. PRINCIPLES OF INHERITANCE AND VARIATIONS 4. MOLECULAR BASIS OF INHERITANCE 5. STRATEGIES FOR ENHANCEMENT IN FOOD PRODUCTION 6. MICROBES IN HUMAN WELFARE 7. BIO-TECHNOLOGY PRINCIPLES AND PROCESSES 8. BIO-TECHNOLOGY AND ITS APPLICATIONS 9. PLANT ECOSYSTEM VOL 1 VOL 2 Chapter Names : Active site edutech- 9844532971
1 MOLECULAR BASIS OF INHERITANCE CHAPTER 4 MOLECULAR BASIS OF INHERITANCE CO N T E N TS NEET SYLLABUS  Introduction  The DNA  The Search for Genetic Material  RNA World  Replication  Transcription  Genetic Code  Translation  Regulation of Gene Expression  Search for genetic material and DNA as genetic material;  Structure of DNA and RNA;  DNA packaging;  DNA Replication;  Central dogma;  Transcription,  Genetic code,  Translation;  Gene expression and regulation- Lac Operon; Active site edutech- 9844532971

3 MOLECULAR BASIS OF INHERITANCE H C2 CH2 HO OH phosphate group OH A deoxyribose sugar molecule linked with phosphate group at 5 position  CH HC CH 5 2 4 1 3 OH O O O P deoxyribose sugar STRUCTURE OF POLYNUCLEOTIDE CHAIN * The chemical structure of a polynucleotide chain (DNA or RNA). * A nucleotide has three components - a nitrogenous base, a pentose sugar (ribose in case of RNA, and deoxyribose for DNA), and a phosphate group. * There are two types of nitrogenous bases -Purines (Adenine and Guanine) and Pyrimidines (Cytosine, Uracil and Thymine). Cytosine, adenine, guanine are common for both DNA and RNA and Thymine is present in DNA. Uracil is present in RNA at the place of Thymine. * A nitrogenous base is linked to the pentose sugar through a N-glycosidic linkage to form a nucleoside, such as adenosine or deoxyadenosine, guanosine or deoxyguanosine, cytidine or deoxycytidine and uridine or deoxythymidine. * When a phosphate group is linked to 5’-OH of a nucleoside through phosphoester linkage, a corresponding nucleotide (or deoxynucleotide depending upon the type of sugar present) is formed. Two nucleotides are linked through 3’-5’ phosphodiester linkage to form a dinucleotide. * More nucleotides can be joined in such a manner to form a polynucleotide chain. * A polymer thus formed has at one end a free phosphate moiety at 5’ phosphate 5’-end of ribose sugar, which is referred to as 5’-end of polynucleotide chain. * Similarly, at the other end of the polymer the ribose has a free 3’-OH group which is referred to as 3’-end of the polynucleotide chain. * The backbone in a polynucleotide chain is formed by sugar and phosphates. The nitrogenous bases linked to sugar moiety project from the backbone * In RNA, every nucleotide residue has an additional -OH group present at 2’-position in the ribose, Also, in RNA the uracil is found at the place of thymine (5-methyl uracil, another chemical name for thymine). * DNA as an acidic substance present in nucleus was first identified by Friedrich Miescher in 1869. * He named it as ‘Nuclein’ However, due to technical limitation in isolating such a long polymer intact, the elucidation of structure of DNA remained elusive for a very long period of time. * It was only in 1953 that James Watson and Francis Crick, based on the X-ray diffraction data produced by Maurice Wilkins and Rosalind Franklin, proposed a very simple but famous Double Helix model for the structure of DNA. * One of the hallmarks of their proposition was base pairing between the two strands of polynucleotide chains. * However, this proposition was also based on the observation of Erwin Chargaff that for a double stranded DNA, the ratios between Adenine and Thymine and Guanine and Cytosine are constant and equals one. Active site edutech- 9844532971