MOLECULAR BASIS OF INHERITANCE 1 скачать в хорошем качестве

MOLECULAR BASIS OF INHERITANCE 1

Molecular Basis of Inheritance | Introduction - Nucleic Acid | Class12th | Part 1 |#NEET | #CBSE | #Concept#nucleicacids#nucleotides#nucleosides DNA and RNA: Location and Discovery DNA (Deoxyribonucleic Acid) Location: In Eukaryotes: DNA is primarily located in the cell nucleus, where it forms part of the chromosomes. Small amounts of DNA are also found in mitochondria (mtDNA) and, in plants, in chloroplasts (cpDNA). In Prokaryotes: DNA is found in the cytoplasm in a region called the nucleoid. Prokaryotes often have a single circular chromosome, and some also contain small, circular DNA molecules known as plasmids. Discovery: 1869: Friedrich Miescher, a Swiss physician, discovered a substance he called "nuclein" (now known as DNA) in the nuclei of white blood cells. He was the first to identify DNA as a distinct molecule. 1953: James Watson and Francis Crick, with contributions from Rosalind Franklin and Maurice Wilkins, discovered the double helix structure of DNA, revealing how genetic information is stored and replicated. RNA (Ribonucleic Acid) Location: In Eukaryotes: RNA is synthesized in the nucleus (where it is transcribed from DNA) and then processed before being transported to the cytoplasm. In the cytoplasm, RNA plays various roles in protein synthesis and gene regulation. Types of RNA include messenger RNA (mRNA), transfer RNA (tRNA), ribosomal RNA (rRNA), and various small RNAs (such as microRNA, siRNA, etc.). In Prokaryotes: RNA is found in the cytoplasm, where it is involved in protein synthesis and regulation of gene expression. Prokaryotic cells do not have a nucleus, so RNA synthesis occurs in the cytoplasm directly from DNA. Discovery: 1868-1869: Johann Friedrich Miescher also identified RNA alongside DNA in the nuclei of cells, though his primary focus was on DNA. 1930s-1950s: The functions of RNA in protein synthesis were discovered through various studies. Severo Ochoa and Arthur Kornberg made significant contributions to understanding RNA synthesis and its role in genetics. The Central Dogma of Molecular Biology, proposed by Francis Crick, outlined the flow of genetic information from DNA to RNA to protein.