Key points to remember
- World’s most ancient known life is 3.5 billion years old cast of a filamentous cyanobacterium obtained from western Australia.
- Euphenics: Science of making phenotypic improvement to human after birth.
- Norman E. Borlaug: Nobel prize (1970) à Green revolution
- Major component of bacterial cell wall à Peptidoglycan
- Nucleolus : Responsible for rRNA synthesis ( NORs)
- Zygonema: Homologous chromosome paired to form bivalent
- Diplonema: Chiasmata formation
- Diakinesis: terminalization
- Lethal: All die before reproduce usually recessive
- Semi lethal : 10% survive
- Sub vital: same individual die
- Vital: no effect on survival
- Supra vital: Increased survival
- Dihybrid ratio: 9:3:3:1
- Duplicate gene action: 15:1
- Complementary gene: 9:7
- Modifying/ Supplementary gene: 9:3:4
- Inhibitory gene: 13:3
- Masking gene: 12:3:1
- Polymeric gene: 9:6:1
- Additive gene” 1:4:6:4:1
- Recombination frequency between two genes can’t exceed 50%.
- DNA capable of replication: replicon
- Helicase/ Primase: Unwind DNA
- DNA gyrase: Removes positive super coiling in DNA
- Replicons: a) Eukaryotes: Several replicons b) Prokaryotes: Single replicons
- Replication process : Initiation à elongation à termination
- Protein involved in replication : DNA polymerase I, II, II, primase, Gyrase, Helicase, Ligase, Endonuclease
- DNAà RNA = transcription
- RNA à Protein = Translation
- Prokaryotes: Polycistronic mRNA
- Eukaryotic : Monocistronic mRNA
- Clover leaf model of tRNA was given by Robert Holley in 1965.
- Mutation that arise due to single change in nucleotide sequence à point mutation
- Mutation that arise due to change in no. and structure of chromosome –. Chromosomal mutations
- Mutable sites within a gene is hot spots
- Haemophilia is a biochemical mutation
- Transition : Purine replaced by purine
- Transversion: Purine replaced by pyrimidine
- Chloroplast are referred as plastids before chlorophyll develops