yourtraits.Traitsarecharacteristicsyouinheritfromyourparents;thismeansyourparentspasssomeoftheir

characteristicsontoyouthroughgenes.Forexample,ifbothofyourparentshavegreeneyes,youmightinherit

thetraitofgreeneyesfromthem.Orifyourmomhasfreckles,youmightinheritthattraitandwindupwitha

freckledface.Andgenesaren'tjustinhumans-allanimalsandplantshavegenes,too.

Geneshangoutalllineduponthread-likethingscalledchromosomes.Chromosomescomeinpairs,andthere

arehundreds,sometimesthousandsofgenesinonechromosome.Thechromosomesandgenesaremadeof

DNA,whichisshortfordeoxyribonucleicacid.

Chromosomesarefoundinsidecells,theverysmallunitsthatmakeupalllivingthings.Acellissotinythat

youcanonlyseeitthroughthelensofastrongmicroscope,andtherearebillionsofcellsinyourbody.Most

cellshaveonenucleus.Thenucleus,whichissortofegg-shaped,islikethebrainofthecell.Ittellseverypart

ofthecellwhattodo.Howdoesthenucleusknowsomuch?Itcontainsourchromosomesandgenes.Tinyas

itis,thenucleushasmoreinformationinitthanthebiggestdictionaryyou'veeverseen.

B.HowDoGenesWork?

C.WhatDoesAGeneConsistof?

D.HowDoNucleusCommandCells?

B.send

C.obtain

D.pass

B.Alllivingthingsreceivetraitsfromtheoldgenerations.

C.One'sgreeneyesmightbepassedonfromtheparents.

D.Amother'sfreckledfacemightaffectheryoung'sface.

B.genesexistinsidecellsthatmakeupal