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Showing posts with the label polygenic

Dunaliella salina - Overview

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                 Dunaliella salina Dunaliella salina is a unicellular microalgae belong to division Chlorophyta . It is found in salinity environments such as salted brines, salt evaporation ponds, and hypersaline lakes  .It is able to tolerate varying NaCl concentrations, ranging from 0.2% to approximately 35% . Thus, Dunaliella salina is a hyper-halotolerant organism found in high densities in saline lakes.  The ability to tolerate high salt concentrations is advantageous, since competition is minimal in high salt concentration areas.  How D.salina   tolerate high salt concentration? D. salina has adapted to survive in high salinity environments by accumulating glycerol to balance osmotic pressure. Note :  D. salina is also adapted to solar radiation using β-carotene to protect against ionizing energy.                 Red Colour of Salt Brines  Dunaliella salina...
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Pleiotropy,polygenic inheritance,lethal genes

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Link of basic terminology(part1) link of mendel work(part2) link of exception of law of domiance ,back and reciprocal cross(part3) Pleiotropy :   Tendency of gene to produce multiple phenotypic effect. ** When a gene control more than one character.This phenomenon is called pleiotropy.Such genes are called pleiotropic genes . **In case of more than one character controlled by a single gene, all the characters are not equally influenced i.e.one character may show dominance,whereas another character may show incomplete dominance, codominance or dominance.Therefore,    dominance is not an autonomous feature of a gene oe its product,it is also dependent on interaction or effect of the product of that gene on a particular character. ** Example: Starch branching enzyme gene (control size of starch grain and shape of grain), phenylketonuria (control synthesis of phenylalanine hydroxylase enzyme,  depigmentation,mental retardation,hair loss,arthritic joints), Heterozygous f...
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