How Traits are Inherited© Copyright NewPath Learning. All Rights Reserved. 94-4421Visit www.newpathlearning.com for Online Learning Resources.spermeggfertilized cell(zygote)FertilizationWhen an egg and sperm come together at fertilization, the embryo receives a copy of each parent’s chromosomes. AAAACCCCGGGGTTTTBBbbBbfatherhomozygousBBhomozygousbbheterozygousBbmotherchildXWhat Is Heredity?Heredity is the passing of traits or characteristics from one generation to the next. What is a Trait?The production of different proteins determines the traits of an organism. A trait is an inherited characteristic.Humans have 46 chromosomes that are present in 23 pairs. One chromosome in each pair is inherited from the mother, and the other from the father. The inherited genes on these chromosomes contain DNA sequences that are related to particular traits. A person inherits two copies of each gene. Homozygous & Heterozygous AllelesA person can inherit two of the same alleles, called homozygous. Or a person can inherit two different alleles, called heterozygous.DNAgenegeneproteintraitfather mothereyebrowshapeeyebrow shapeBbfather motherallelesAlleles - Alternate Gene FormsGenes exist in alternate forms called alleles. For example, the gene that determines eyebrow shape has two alleles—one codes for bushy eyebrows and the Bbspermeggfertilized ceeeeeeeellllllllllllllllllllll(zygote)When an egg and sperm come together at fertilization, the embryo receives a copy of each parent’s chromosomes. AAAAAAAAACCCCCCCCGGGGGTTTTTTTTTTTTTTTTTTBBBBBBBBBBBBBBBbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbBBBBBBBBBBBBBBBBBBBBBBbbbbbffffffattttttttthhhhhhhhhhhhhheeeeeeeeeeeeeerrrrrrrrrrrhommmmmmmmmmmmmmmmozzzzzzzzzyyyyyyyyyyyyyyyyyygggggggggggggggggooooooouuuuuuuuuuuuuussssssssssBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBhhhhhhhhooooooooooooooommmmmmmmmmmmmmmmooooooozygoouuuuuuuuuusssssssssssssssssbbbbbbbbbbbbbbbbbbbbbbbbbbhhhhhhhhhhhhhheteeeeeeeeeeeeeeerrrrrrrrrrrrroooooooooooozygousBbmotherchildHeredity is the passing of traits or characteristicsfrom one generation to the next. The production of different proteins determines the traits of an organism. A trait is an inherited characteristic.HHHHHuuuuuuuuuuuuuummmmmmmmmmmmmmmmmaaaaaaaaaaannnnnnnnssssssssss hhhhhhhhhhhhhhaaaaaaaaave 444444444444444466666666666666 cccccccccccchhhhhhhhhhhhhhhhrrrrrrrrrooooooooooooommmmmmmmmmmmmmmmooooooooooooosomes tttttthhhhhhhhhhhhhhhhhaaaaaaaaaattttttttttttt aaaaaaaaaaaaaaaarrrrrrrrrrreeeeeeeeeee ppppppppppppprresent in 23 ppppppppppppppppppppaaairrrrrrrrsssssssssssss.. OOOOOOOOOOOOOnnnnnnnnnnne cccccccccchhhhhhhhhhhhhhhhrommmmmmmmmmmmmmmmmooooooooooooossssssssssoooooooooooooommmmmmmmmmmmmmmmmmmeeee in each ppppppaaaaaaaaaaaaaiiiiiiiiiiiiiirrrrrrrrrrrrr iiiiiiiis iiiiiiiiiiiiiiinnnnnnnnnnnnnnnnnhhhhhhhhhhhhhheeeeerited from tthhhhhhhhhhhhheeeeeeeeeeeeeee mothhhhhhhhhhhhheeeeeeeeeeerrrrrrrr, aaaaaaaaaannnnnnnnnd thhhhhhhhhhhhheeeeeeeeeeeee ooootttttttttttttthhhhhhhhhhhhhhhhhhhheer frommmmmmmmmmmmmmmmmm tttttttthe fattttttthhhhhhhhhhhhhhhheeeeeeeeeeeeeerrrrrrrrrrrr... TTTTTTTTTTTTTTTThhhhe inhheeeeeeeeeeeeeerrrrrrrrrrrrriiiiiiiteeeeeeeeeedddddddddddddd genes ooooooooooonnnnnnnnnnnnn ttttttthese cccccccccchhhhhhhhhhhhhhhhhhrrrrrrrrrrrrooooooooooommmmmmmmmmmoooooooooooooooosssssssssssooooooooomes contain DDDDDDDDDDDDDDDDDDDDNNNNNNNNNNNNNNNNAAAAAA ssssssssssseeeeeeeeeeeeeeqqquuuuuuuuuuuuuueeeeeeeeeeeeeeences that are rrreeeeeeeeeeeellllllllaated ttooooo pppppppppppppppaaaaaaaaaaaaarrrrrrrrrrtttttttttttttiiiiiiiiiiicccccular traits. A ppppppppppppppppppppeeeeeeeersooooooooonnnnnnnnnnnnn iinnnnnnnnnnnnnnhhhhhhhhhhhhhhherits two copiiiiiiieeeeeeeeeeeesssssssssssssss oooooooofffffffffffffff eeeeeeeeeeeeeaaaaaaaaaaacch gene. A person can inherit two ooooooooooooooooooooffffffffff thee ssssssssaaaaaaaaaaaaammmmmmmmmmmmmmmmeeeeeeeeeeeeeeeeeee aaaaaaaaaaaaaaalllllllllllllllllllllleeeeeeeeelllllllllleeeeees, called homozygous. Or a person ccccccccccaaaaaaaaaaaaaaaaannnnnnnnnnnnnnn iiinhhhhhhhhhhhhhhheeeeeeeeeeeeerrrrrrrrrrrrrrriiiiiiiiiiitttttttttt ttwo differentalleles, called heterozyyyyyyyyyyyygggggggggous.DNAenegegenepppppppppppppprrrrrrrrrrrooooooooooootttttttteeeeeeeeeeeeeeeeeiiiiiiiiinnnnnnnnnnnnntttttttttttttttttrrrrrrrrrraaaaaaaaaaaaaiiiiiiiiiitttttttttttttttffffaaaaaaaatttttthhhhheeeerrrrrrr mmmmmmmmmothereyebrowshapeeyebrow shapppppppppppppppppeeeeeeeeeeeeeeeeebbbbbBBBbbbbbfather motherallelesGGGGGGGGGGGGGGGGGGGGGGGGeeeeeeeeeeeeneeeeeeeeeeeeeesssssssssssss eeeeeeeeeeeeeeeexxxist in alternate forms called alleles. For eeeexxxxxxxxxxxxxaaaaaaaaaaaaammmmmmmmmmmmmmmmmmmmmpppppppppppppppppppllllle, the gene that determines eyebrow shape has ttttttttttttttwwwwwwwwwwwwwwwwwwwwooooooooooooooooo aaaaaaaaaaaaalleles—one codes for bushy eyebrows and the
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