Molecular Genetics
Molecular Genetics
The phenotype of a cell or organism is determined jointly by the organisms genotype and environment The genotype consists of the genes that control the trait of interest A gene is a segment of a DNA molecule (or RNA in some viruses) The genome of an organism is (i) the sum of all of the DNA in one set of chromosomes (broad sense); (ii) the sum of all of the genes in one set of chromosomes (narrow sense) DNA – Deoxyribonucleic acid o Purines (A, G) o Pyrimidines (C, T)
Chargaff rule: T + C = G = A; T = A and G = C; but A + T = G + C
Junk DNA? – some non-coding regions are transcribed into Ribosomal RNA (rRNA) and transfer RNA (tRNA), but most of their functions are unknown o Non-coding regions: 2% in Bacterium DNA. 98% in human DNA Eukaryotes – in eukaryotes genes are composed of introns and exons o Exons – code for protiens o Introns – non-coding
The phenotype of a cell or organism is determined jointly by the organisms genotype and environment The genotype consists of the genes that control the trait of interest A gene is a segment of a DNA molecule (or RNA in some viruses) The genome of an organism is (i) the sum of all of the DNA in one set of chromosomes (broad sense); (ii) the sum of all of the genes in one set of chromosomes (narrow sense) DNA – Deoxyribonucleic acid o Purines (A, G) o Pyrimidines (C, T)
Chargaff rule: T + C = G = A; T = A and G = C; but A + T = G + C
Junk DNA? – some non-coding regions are transcribed into Ribosomal RNA (rRNA) and transfer RNA (tRNA), but most of their functions are unknown o Non-coding regions: 2% in Bacterium DNA. 98% in human DNA Eukaryotes – in eukaryotes genes are composed of introns and exons o Exons – code for protiens o Introns – non-coding
