MEMORY CAPSULES & MEMORY CHARTS
Different types of nucleic acids present in viruses
Many animal viruses.
Many plant viruses TMV
Zoophages-polio virus, Influenza virus
Phyto phages-Wound tumour virus,Maize rough dwarf virus,Rice dwarf virus
Zoo phages-Reo virus
Blue tongue virus
Shape – Rod. Length – 300 nm
Diameter – 18 or 19 nm
No. of capsomeres – 2,130 Symmetry – Helical
Type of Nucleic acid – ss RNA Type of virus – Phytophage
Diameter of central hole – 4nm/40A° No. of amino acids in a polypeptide chain – 158
Length of m RNA involved in the synthesis of each capsomer of TMV – 1621.8A°
No. of nucleotides present in the mRNA involved in the synthesis of each capsomer of TMV – 477
No. of nucleotides in the RNA – 6500 Length of RNA – 22100 A°
Ø Length of head – 65 nm
Ø Breadth of head – 95 nm
Ø Shape of head – Hexagonal
Ø Shape of virus – Tad pole
Ø Shape of tail – Rod
Ø Type of nucleic acid – ds DNA
Ø Length of tail – 95 nm
Ø Diameter of tail core – 8 nm
Ø No. of capsomeres in tail – 144
Ø Capsomere rings in tail – 24
Ø Shape of the tail plate – Hexagonal
Ø No. of capsomeres in each ring – 6
Ø No. of appendages attached to the tail – 12
Ø Approximate length of bacteriophage – 160 nm
Ø Approximate length of bacteriophage DNA – 1,60, 000 nm = 0.16 mm
Sequence of changes takes place during lytic cycle
Collision between the virions and the bacterial cells- The phages get attached to the surface of the host at specific sites - Secretion of lysozyme - Formation of a hole in bacterial cell wall due to the action of lysozyme - Injection of phage DNA in to the host cell - Degradation of host DNA - Synthesis of coat proteins - Replication of phage DNA- Synthesis of different components of capsid - Assemblage of components and formation of complete virions - Host cell wall ruptures due to the action of lysozyme and the virisons are released.
Anton van leeuwenhoek
Louis Pasteur and Robert koch
Lederberg and Tatum
Lederberg and Zinder
Pierie and Bawden
Gierrer and Schramm
Frankel and Conrat
Franklin et al
Felix ‘d’ Herelle
Discovered pencillin from a fungus penicillium notatum
Isolated an antibiotic from a bacterium Streptomyces griseus
Discovered bacteria, coined the term “Animal cules”.
Coined the term “Bacteria”.
Discovered the pathogenic nature of Bacteria.
Proposed three kingdom classification and placed bacteria under protista.
Proposed five kingdom classification, placed bacteria under monera.
Developed gram staining technique.
Discovered bacterial transformation in Streptococcus pneumoniae.
Discovered bacterial conjugation in E.coli
Discovered transduction Salmonella typhimurium
Discovered an ever largest bacterium Thiomargarita namibiensis
Developed vaccine for small pox
Developed vaccine for rabbies, coined the term virus, proposed germ theory of disease and established Pasteur research institute
Said that A virus is a virus, former director of Pasteur research
Discribed viruses as “contagium vivum fluidum”.
Chemical analysis of viruses.
Discovered that the TMV is made up of nucleic acid and proteins.
Proved the nature of nucleic acid as infections agent and genetic material
Discovered that the genetic material in TMV is RNA
Described the structure of TMV
Coined the term bacteriophage
Breaking of flowers
Whitening or yellowing of entire leaf
Loss of chlorophyll in isolated patches
Loss of chlorophyll in the tissues close to veins
Loss of chlorophyll in the lamina except in areas of veins
Loss of chlorophyll in circular spots.
Loss of colour at certain parts and formation of dark colour at certain parts
Peach yellowing disease
Tobacco mosaic disease, Bean mosaic, Papaya mosaic , Cauliflower mosaic
Bhendi vein clearing
Citrus vein banding
Tomato spotted wilt, cherry ring spot, papaya ring spot
Swollen shoot of cocoa
Tulip mosaic break
TRANSMISSION OF VIRUSES
(Post fertilized form of ovule)
(First cell of male gametophyte)
Phanerogamic parasites (Cuscuta)
(Complete stem parasite)
Potato virus, Sugar cane virus, Banana virus
Potato virus, TMV
Bean mosaic, Lettuce mosaic
Cherry ring spot virus
Rice tungro, potato leaf roll, papaya mosaic
Soil borne viral diseases
TNV, soil borne viral diseases.