Punne%SquareandDyhybridCrosses

SpongeBobGene8cs1&2

Scien&stsatBikiniBo.omshavebeeninves&ga&ngthegene&cmakeupoftheorganismsinthiscommunity.

Usetheinforma&onprovidedandyourknowledgeofgene&cstoanswereachques&on.

1.   Foreachgenotypebelow,indicatewhetheritisaheterozygous(He)ORhomozygous

(Ho).

TT_____Bb_____DD_____Ff_____%_____dd_____Dd_____ff_____Tt_____bb_____BB_____FF_____

Whichofthegenotypesin#1wouldbeconsideredpurebred?

Whichofthegenotypesin#1wouldbehybrids?

2.Determinethephenotypeforeachgenotypeusingtheinforma&onprovidedaboutSpongeBob.Yellowbodycolorisdominanttoblue.

YY________________Yy________________yy________________Squareshapeisdominanttoround.

SS________________Ss________________ss________________

3.Foreachphenotype,givethegenotypesthatarepossibleforPatrick.Atallhead(T)isdominanttoshort(t).

Tall=_______________Short=_______________Pinkbodycolor(P)isdominanttoyellow(p).

Pinkbody=_____________Yellowbody=_________________

4.SpongeBobSquarePantsrecentlymetSpongeSusieRoundpantsatadance.SpongeBobisheterozygousforhissquareshape,butSpongeSusieisround.CreateaPunne.squaretoshowthepossibili&esthatwouldresultifSpongeBobandSpongeSusiehadchildren.HINT:Readques&on#2!A. Listthepossiblegenotypesandphenotypesfortheirchildren.

B.Whatarethechancesofachildwithasquareshape?____outof____or____%C.Whatarethechancesofachildwitharoundshape?____outof____or____%

5.PatrickmetPaYatthedance.Bothofthemareheterozygousfortheirpinkbodycolor,whichisdominantoverayellowbodycolor.CreateaPunne.squaretoshowthepossibili&esthatwouldresultifPatrickandPaYhadchildren.HINT:Readques&on#3!A. Listthepossiblegenotypesandphenotypesfortheirchildren.

B.Whatarethechancesofachildwithapinkbody?____outof____or____%C.Whatarethechancesofachildwithayellowbody?____outof____or____%

6.EveryoneinSquidward’sfamilyhaslightblueskin,whichisthedominanttraitforbodycolorinhishometownofSquidValley.Hisfamilybragsthattheyarea“purebred”line.Herecentlymarriedanicegirlwhohaslightgreenskin,whichisarecessivetrait.CreateaPunne.squaretoshowthepossibili&esthatwouldresultifSquidwardandhisnewbridehadchildren.UseBtorepresentthedominantgeneandbtorepresenttherecessivegene.A. Listthepossiblegenotypesandphenotypesfortheirchildren.

B.Whatarethechancesofachildwithlightblueskin?____%C.Whatarethechancesofachildwithlightgreenskin?____%D.WouldSquidward’schildrens8llbeconsideredpurebreds?Explain!

7.AssumethatoneofSquidward’ssons,whoisheterozygousforthelightbluebodycolor,marriedagirlthatwasalsoheterozygous.CreateaPunne.squaretoshowthepossibili&esthatwouldresultiftheyhadchildren.A. Listthepossiblegenotypesandphenotypesfortheirchildren.

B.Whatarethechancesofachildwithlightblueskin?____%C.Whatarethechancesofachildwithlightgreenskin?____%

8.Mr.KrabbsandhiswiferecentlyhadaLil’Krabby,butithasnotbeenahappyoccasionforthem.Mrs.Krabbshasbeenupsetsinceshefirstsawhernewbabywhohadshorteyeballs.Sheclaimsthatthehospitalgoofedandmixedupherbabywithsomeoneelse’sbaby.Mr.Krabbsishomozygousforhistalleyeballs,whilehiswifeisheterozygousforhertalleyeballs.Somemembersofherfamilyhaveshorteyes,whichistherecessivetrait.CreateaPunne.squareusingTforthedominantgeneandtfortherecessiveone.A. Listthepossiblegenotypesandphenotypesfortheirchildren.

B.Didthehospitalmakeamistake?Explainyouranswer.

1.  Usetheinforma8onforSpongeBob’straitstowritethephenotype(physicalappearance)foreachitem.

(a)LL-______________(e)Rr-_______________

(b)yy-_______________(f)ll-_______________

(c)Ss-_______________(g)ss-_______________

(d)RR-_____________(h)Yy-______________

2.Usetheinforma8oninthechartin#1towritethegenotype(orgenotypes)foreachtraitbelow.

(a)  Yellowbody-___________(e)Stubbynose-___________

(b)Roundpants-___________(f)Roundeyes-____________

(c)Ovaleyes-______________(g)Squarepants-___________

(d)Longnose-_____________(h)Bluebody-____________

3. Determine the genotypes for each using the information in the chart in #1.

(a) Heterozygous round eyes -_____ (c) Homozygous long nose - ______

(b) Purebred squarepants - ______ (d) Hybrid yellow body - ______

4.OneofSpongeBob’scousins,SpongeBillyBob,recentlymetacutesquarepantsgal,SpongeGerdy,atalocaldanceandfellinlove.Useyourknowledgeofgene8cstoanswertheques8onsbelow.(a) IfSpongeGerdy’sfatherisaheterozygoussquarepantsandhermotherisaroundpants,whatishergenotype?CompletethePunne%squaretoshowthepossiblegenotypesthatwouldresulttohelpyoudetermineGerdy’sgenotype.WhatisGerdy’sgenotype?(b)SpongeBillyBobisheterozygousforhissquarepantsshape.Whatishisgenotype?(c)CompletethePunne%squaretoshowthepossibili8esthatwouldresultifBillyBob&Gerdyhadchildren.(d)Listthepossiblegenotypesandphenotypesforthekids.(e)Whatistheprobabilityofkidswithsquarepants?(f)Whatistheprobabilityofkidswithroundpants?

5.SpongeBob’sauntanduncle,SpongeWilmaandSpongeWilbur,havethebiggestroundeyesinthefamily.Wilmaisbelievedtobeheterozygousforherroundeyeshape,whileWilbur’sfamilybragsthattheyareapureline.CompletethePunne%squaretoshowthepossibili8esthatwouldresultifSpongeWilmaandSpongeWilburhadchildren.(a) Givethegenotypeforeachperson.(b) Wilma–Wilbur-(b)CompletethePunne%squaretoshowthepossibili8esthatwouldresultiftheyhadchildren.(c)Listthepossiblegenotypesandphenotypesforthekids.(d)Whatistheprobabilitythatthekidswouldhaveroundeyes?(e)Whatistheprobabilitythatthekidswouldbeovaleyes?

6.SpongeBob’smotherissoproudofhersonandhisnewwife,SpongeSusie,astheyareexpec8ngali%lesponge.Sheknowsthattheyhavea50%chanceofhavingali%leroundpants,butisalsohopingthenewarrivalwillbeblue(arecessivetrait)likeSpongeSusieandmanymembersofherfamily.IfSpongeBobisheterozygousforhisyellowbodycolor,whatarethechancesthatthebabyspongewillbeblue?CreateaPunne%squaretohelpyouanswerthisques8on.

7.SpongeBob’sauntisfamousaroundtownforheri%y,bi%ystubbynose!Sherecentlymetacutesquarepantsfellowwhoalsohasastubbynose,whichisarecessivetrait.Woulditbepossibleforthemtohaveachildwitharegularlongnose?Whyorwhynot?CreateaPunne%squaretohelpyouanswerthisques8on.

8.IfSpongeBob’sauntdescribedin#7wantedchildrenwithlongnoses,whattypeoffellowwouldsheneedtomarryinordertogiveherthebestchances?CreateaPunne%squaretohelpyouanswerthisques8on.

Dihybrid Cross: a cross that shows the possible

offspring for two traits

Fur Color: B: Black b: White

Coat Texture: R: Rough r: Smooth

In this example, we will cross a heterozygous individual with another

heterozygous individual. Their genotypes will be:

BbRr x BbRr

Dihybrid Cross

BbRr x BbRr Step 1: Find ALL possible gametes that can

be made from each parent. Remember, each gamete must have one B

and one R.

Dihybrid Cross BbRr x BbRr

Possible gametes: BR Br bR br

Step 2: Arrange all possible gametes for one parent on

the top of your Punnett Square and the other parent

on the side

Dihybrid Crosses: a cross that shows the possible offspring for two traits

Fur Color: B: Black b: White

Coat Texture: R: Rough r: Smooth

BbRr x BbRr BR bR

br

bR

Br

BR

br Br

Step 3: Fill in the Punnett Square

(find the possible genotypes of the

offspring)

Dihybrid Crosses: a cross that shows the possible offspring for two traits

Fur Color: B: Black b: White

Coat Texture: R: Rough r: Smooth

BbRr x BbRr BR bR

br

bR

Br

BR

br Br

BBRR BbRR BbRr

BBRr BBrr BbRr Bbrr

BbRR BbRr bbRR bbRr

BbRr Bbrr bbRr bbrr

BBRr

BR bR

br

bR

Br

BR

br Br

BBRR BbRR BbRr

BBRr BBrr BbRr Bbrr

BbRR BbRr bbRR bbRr

BbRr Bbrr bbRr bbrr

BBRr

How many of the offspring would have a

black, rough coat?

How many of the offspring would have a black, smooth coat?

How many of the offspring would have a

white, rough coat?

How many of the offspring would have a white, smooth coat?

Fur Color: B: Black b: White

Coat Texture: R: Rough r: Smooth

BR bR

br

bR

Br

BR

br Br

BBRR BbRR BbRr

BBRr BBrr BbRr Bbrr

BbRR BbRr bbRR bbRr

BbRr Bbrr bbRr bbrr

BBRr

How many of the offspring would have black, rough coat?

How many of the offspring would have a black, smooth coat?

How many of the offspring would have a

white, rough coat?

How many of the offspring would have a white, smooth coat?

Fur Color: B: Black b: White

Coat Texture: R: Rough r: Smooth

Phenotypic Ratio=

9:3:3:1

Practice in your notes…

In pea plants, yellow seeds (Y) are dominant over green seeds (y), and rounded peas (R) are dominant over wrinkled peas (r).

Cross (what do you have to draw?) a plant that is

heterozygous for both traits with a plant that is homozygous recessive for both traits. Draw a Punnett square to show all possible offspring, and determine the genotypic and phenotypic ratios.

YyRr X yyrr

YR yR

yr

yr

yr

yr

yr Yr

YyRr yyRr yyrr

YyRr Yyrr yyRr yyrr

YyRr Yyrr yyRr yyrr

YyRr Yyrr yyRr yyrr

Yyrr