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Page 1: content.kopykitab.com• The inheritable characteristics may be morphological / anatomical / physiological / reproductive and are known as traits. • Gregor Johann mendel carried
Page 2: content.kopykitab.com• The inheritable characteristics may be morphological / anatomical / physiological / reproductive and are known as traits. • Gregor Johann mendel carried
Page 3: content.kopykitab.com• The inheritable characteristics may be morphological / anatomical / physiological / reproductive and are known as traits. • Gregor Johann mendel carried
Page 4: content.kopykitab.com• The inheritable characteristics may be morphological / anatomical / physiological / reproductive and are known as traits. • Gregor Johann mendel carried
Page 5: content.kopykitab.com• The inheritable characteristics may be morphological / anatomical / physiological / reproductive and are known as traits. • Gregor Johann mendel carried
Page 6: content.kopykitab.com• The inheritable characteristics may be morphological / anatomical / physiological / reproductive and are known as traits. • Gregor Johann mendel carried
Page 7: content.kopykitab.com• The inheritable characteristics may be morphological / anatomical / physiological / reproductive and are known as traits. • Gregor Johann mendel carried
Page 8: content.kopykitab.com• The inheritable characteristics may be morphological / anatomical / physiological / reproductive and are known as traits. • Gregor Johann mendel carried
Page 9: content.kopykitab.com• The inheritable characteristics may be morphological / anatomical / physiological / reproductive and are known as traits. • Gregor Johann mendel carried
Page 10: content.kopykitab.com• The inheritable characteristics may be morphological / anatomical / physiological / reproductive and are known as traits. • Gregor Johann mendel carried

HEREDITY AND EVOLUTION 1

• Theinheritanceofcharacteristicsthroughgenerationsiscalledheredity.• Theinheritablecharacteristicsmaybemorphological/anatomical/physiological/reproductiveandareknownastraits.

• GregorJohannmendelcarriedoutseveralexperimentsonheredity.• Mendelconcludedthatoutofanypairofcontrastingcharacters,oneisdominantandtheotherisrecessive.• The homozygous dominant trait is denoted by two capital letters whereas the homozygous recessive trait isdenotedbytwosmallletters.

• Theexpressionofmorphologicalcharactersiscalledphenotype.• Theexpressionofgeneofanindividualforaparticulartraitiscalledgenotype.• The genotype of a character is influenced by genes. Genes are the factors which form the physical basis forinheritanceofcharacters.

• Thealternateexpressionofthesamegenearecalledalleles.• Thecontrastingpairofallelesmakeupanallelomorph.• Organismsdifferinexpressingphenotypewhichleadstovariation.• ChangesoccurringintheDNAofgermcellsareheritablewhereaschangestakingplaceinthenon-reproductivetissuesarenotinherited.

• CharlesDarwinproposedthatevolutionofspecies is influencedbynaturalselection,buthedidnotknowtheunderlyingmechanism.

• Evolutionisaslowprocessandhasoccurredovermillionsofyears,asrevealedbyfossilevidences.• Theageoffossilscanbedeterminedbyusingtherelativemethodortheisotopedatingmethod.• Evolutionhasresultedinthediversityoforganisms.• Allhumanbeings,whetherfairskinnedordarkskinned,belongtothesamespeciesi.e.,Homo sapiensthatoriginatedinAfrica.

• The human ancestors gradually migrated from Africa to various parts of the world such as Asia, Europe,AustraliaandAmerica.Thustheyspreadtodifferentpartsoftheearthandadaptedasbestastheycouldtotheirenvironmentalconditions.

• GeneticengineeringisthemodificationofthegeneticinformationoflivingorganismsbymanipulationofDNAbyadding,removingorrepairingpartofgeneticmaterial(DNA)andchangingthephenotypeoftheorganism.ItisalsoknownasgenemanipulationorrecombinantDNATechnology(r-DNATechnology)

• Bio-technology has contributed towards exploitation of biological organisms or biological processes throughmoderntechniqueswhichcouldbeprofitablyusedinmedicine,agriculture,animalhusbandryandenvironmentalcleaning.

1Heredity and Evolution

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