Molecular Biology Ppt - Copy

7/31/2019 Molecular Biology Ppt - Copy

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Assistant Professor

Department of Biotechnology

Government College of Technology

Coimbatore-641013

Lakshmi Priya ThyagarajanJan 30 2012 11:20 PM


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A few words about Father of Classical Genetics

Garden pea: experimental material of Mendelswork

Steps of Mendels Experiment

Mendels laws of inheritance

Deviation from Mendelian laws

Applications of Mendelian laws


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Monohybrid cross

Trait flower color

(purple & white)Pureline

Result:

F1 generation: all

purple flowersF2 generation: 75%

purple and 25%

white


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Incomplete Dominance

Co-dominance


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A gene can have more than two alleles, i.e.,

multiple allelism

e.g. human blood types

Phenotypes of some heterozygotes reveal

types of dominance other than full

dominance

Many genes have alleles that can kill theorganism (contd.)


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Hershey-Chase Experiment

Griffiths Experiment

Avery, Mc Leod and Mc Carty Experiments


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Transformation

Griffith discovered transformation in

1928, 17 years later Avery, MacLeod and

McCarty demonstrated that DNA was thetransforming principle.

What is its importance besides these

discoveries?

Steps involved in transformation

Co-transformation


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Transduction

Generalised and Specialised Transduction


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Conjugation


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Different forms of DNA


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DNA ---------------- RNA-------------- protein

Replication

transcription translation


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Replication DNA making a copy of itself Making a replica

Transcription DNA being made into RNA Still in nucleotide language

Translation RNA being made into protein

Change to amino acid language


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Eukaryotic topoisomerases can relax positive

supercoils.Relaxing the unbound positive

supercoil leaves the negative supercoil fixed

(through its binding to the nucleosome

histone core) and results in an overall

decrease in linking number. Indeed,

topoisomerases have proved necessary for

assembling chromatin from purified histones

and closed-circular DNA in vitro.

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Molecular Biology Ppt - Copy