Scribd
Upload
262 views18 pages

Heredity Practice Problems Key

heredity

Uploaded by

Toha Putra
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF or read online on Scribd
262 views18 pages

Heredity Practice Problems Key

heredity

Uploaded by

Toha Putra
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF or read online on Scribd
You are on page 1/ 18
Punnett Square Practice Problems Gamete Formation ‘Name Hour 1. Kelp, a large, multicellular type of algae, has air bladders in the blades to help them float near the surface of the ocean where they can get more sunlight. Assume that having many air bladders is a dominant trait, What gametes would be produced by a heterozygous individual? Key : ML oir Mmm 2 SS aic Bodders Genotype Mm "| Gametes: O-@& 0h ean What gametes would be produced bj a homozygous dominant individual? Genotype MM Gametes @) 100% 2. In humans, sickle cell anemia is a disease caused by a mutation of a single locus gene that codes for an important blood protein. The allele for the normal protein is dominant to that for the one causing sickle cell anemia, What gametes would be produced by an individual who suffers fro 1m sickle cell anemia? Key Se F normal D2 scKo Col Genotype XQ. Gametes © 100% What gametes would be produced by recessive cross? GS x pao individuals resulting from a homozygous dominant x homozygous Resulting genotype Gametes @ & Sa S«@ SOA A each 3. In areas of the very deep and damp southeastern United States lives what is, essentially, a giant lying cockroach known as a Palmetto bug. wings are dominant to bent ones. What gametes will be produced by an indi for antennae and heterozygous for wir ings? Assume that long antennae are dominant to short antennae and that normal ividual that is homozygous dominant Key L. slong antentee Me antennas 2 Aotmnal WARDS, Genotype LUNn Gametes one &® nd> loont wings _ What gametes will be produced by an individual that is heterozygous for antennae and homozygous recessive for wings? Genotype LUnn Gametes @ « & BOR dy each 4, In horses, the color black is due to by a homozygous black pacer? trotting gait is due to a dominant allele and the pacing gait to the recessive. a dominant allele and chestnut color is due to the recessive allele. The ‘What will be the gametes produced Key Genotype Gametes 1B. = Black Eee sueiaiet Bett 2 teatting, th pacing \oor Suppose we eross the black pacer above with a homozygous chestnut trotter. What will be the gametes produced by the offspring? Parental Genotypes BV’ x DTT Parental Gametes. ® <& Bott Resulting genotype of offspring Bote ‘Gametes produced by the offspring 25% chond@ ch each 5. Suppose you are designing a new Jurassic Park and you would like to have the crowd drawing presence of Velociraptor without the danger of having your crowds eaten. You have managed to come up with two varieties, very aggressive, which is apparently a dominant trait in Velociraptors, and non-aggressive. They also come in two colors, red, whiel is dominant, and green, Now you have a green female that is homozygous dominant for aggression and a non-aggressive male that is homozygous dominant for color. What gametes will be produced by the male and female? Key ; R= red Parental Genotypes @ ochA ot REan. Parental Gametes @® “eD ‘What gametes will be produced by the offspring of these two Velociraptors (providing of course that the female doesn't dismember the male before mating)? Cross Reo Resulting genotype of the offspring Gametes produced by the offspring Reha (Bh Ge EA) eS 25% chonce each Monohybrid Crosses iG In rabbits the allele for black coat color is dominant over the allele for brown coat color. What would the genotypic ratio and phenotypic ratio be for a cross between an animal homozygous for black coat color and one homozygous for brown coat color? Parental genotypes Parental gametes eS = tb ®-® Genotypic description and Ratio. ‘Phenotypic description and Ratio (00% Bo beter ea) (00% Bock 2. White hair in sheep is caused by the dominant gene while black hair is male and a black female are parents of a black lamb. What is the probability that their next lamb will be white? What are the genotypic and phenotypic ratios? recessive. A heterozygous white Key Parental genotypes Parental gametes IW. = Waite GW QD oo YS) gan > black = ww © ‘Cross 7 @ 7 @) Probability next lam| ite Genotypic description and Ratio BO% chance Nexk Who * wows wv) No vw tol ss WUE us Phenotypic description and Ratio Wiwite ? Brack ind 3. Albinism is recessive in humans. An albi man marries a woman who is not albino, but had an albino father. What is the probability of this couple having a child that is not an albino? What are the genotypic and phenotypic ratios? Key AL> Not abbing lag. = GAbinn Parental genotypes C= On Behe Parental gametes “e e« © Probability child is not albino 5O% chance. rid is vot albino Genotypic description and Ratio Ket om uel Phenotypic description and Ratio ot allsinn ? albing bey 4, Todd and Melissa are college students who are planning to get married. They are currently taking a genetics course and decided to determine the eye color of any possible children they might have. Blue eyes are recessive to brown eyes. Todd has brown eyes, like his three brothers. His mother and grandmother have blue eyes, but his father and all other grandparents have brown eyes. Brown eyed Melissa has one blue eyed sister and one brown eyed sister and a mother with blue eyes. Her father and all of her grandparents have brown eyes. Construct an accurate Punnett square to determine the possible eye colors of their yet to be born children, What are the genotypic and phenotypic ratios? Parental genotypes [Todd = BL Moussa, Bb © Genotypic description and Ratio BB Bb bb he ge Phenotypic description and Ratio er ; Bue Fees = 5, In Teenage Mutant Ninja Turtles, heterozygous for a green shell, m: genotypic and phenotypic ratios of their possible offspring? , green shells are dominant over brown shells. Leonardo, who is jarries the lovely Mona Lisa, who has a brown shell. What are the Ke; a. Bageen Shells ggy7 bowen shells Parental genotypes leonardo Ga Movin. Lisa 9 Parental gametes @ cms E} a @S& Genotypic description and Ratio Ga 9% cet Phenotypic description and Ratio Arsen? Brown Soh Sal Re In humans, polydactyly (an extra finger on each hand or toe on each foot) is due to a dominant gene, When one parent is polydactylous, but heterozygous, and the other parent is normal, what are the genotypic and phenotypic ratios of their possible offspring? 6. Key Parental genotypes Parental gametes E_ = Qolyhastyl FR x AE ©e-® Lee = norwok x @) Phenotypic description and Ratio Cross © © eee and Ratio a crap ate © £e uel v4 Dihybrid Crosses In human, aniridia, (a type of blindness resulting from absence of an iris) is due to a dominant gene. igraine (a sickening headache) is due to a different dominant gene. A man with aniridia, whose mother was not blind, marries a woman who suffers from migraine. The woman’s father did not suffer from migraine. In what proportion of their children would both aniridia and migraine be expected to occur? Key Parental genoiypes Parental gametes Az anicidio. OA VG So laa.= Wormald IM_ = Migcatet er © Cros: Proportion of Children with both ae. anitidia and migraine toe of GY faim an.Mmn, 25% ee (=) Rew om, hnindte, ond Migraines) In 2, In watermelons, solid green color is dominant over striped pattern, and short shape is dominant over long shape. What is the probability of each phenotype of possible offspring if'a heterozygous solid, long, ‘watermelon cross pollinates with a heterozygous solid, heterozygous short watermelon? Key Parental genotypes Parental gametes soid een a Goa * GySa - 2 shot e 20 long A826 Cross Description and probability of each © & © (@2) GaSo Game Gf Goo be) Gyn Gao 9% aye possible phenotype 3 aed (37.52) shied = 3 (27.54) [Sauce Grea ts (\2.62) Lory rset <4 (12.52) heterozygous for both traits? 3. Having two eyebrows is dominant over having one large eyebrow (uni-brow). Also having six fingers is dominant over having five fingers. What is the probability of each possible phenotype of their offspring if a ‘man that has one eyebrow and is heterozygy gous for having six fingers reproduces with a woman that is Key E_ = Aun eyporus lee = Unibrowd TEL + tn Plegecs leg 2 Cive rogers Parental genotypes Bo ee¥k 2 REL Parental gametes “@@ @O® LE Gece Cert at eck Gael TAKE eeFl ene Description and probability of each possible phenotype Tis boust - 2 33.5) Six reps S ( olormunt . 1 (2.5%) ee § « ) Incomplete Dominance 1. Yellow coat color in guinea pigs is produced by the homozygous genotype, and cream color by the heterozygous genotype. White is produced by the homozygous genotype. What genotypic ratios are expected by crosses between cream colored guinea pigs? Describe the phenotypic ratio. Parental genotypes Ny «YY Parental gametes © @® x or Genotypic description and Ratio WY? yy veze Phenotypic description and Ratio Nellans : Cream + Wie, Wez a S22) beh Wh 2. Inhumans hair texture is controlled by incomplete dominance. A curly haired individual and a straight haired individual have all wavy haired children. If two wavy haired people have children, what will the phenotypic ratio be? Key Parental genotypes Parental gametes Wy Carty Mw * Hh oc Hey = Noung, x Whe Sstrasghl @© w & Cross ® ® Phenotypic description and Ratio + Way yt Skeaighet W ik Gals 4 ‘i a. In Japanese four o’clock flowers, color is inherited by genes that show incomplete dominance. In such lowers, a cross between a homozygous red flower and a homozygous white flower will always result in pink flowers. a. What is the genotypic and phenotypic ratio for a cross between a plant with red flower and a plant with pink flowers? Rey ERe ced Ace pine cee WWte Parental genotypes Wx Ke Parental we : @« © Cross: @ & @® ew & Genotypic description and Ratio ee: Re a Phenotypic description and Ratio Red : Vina A= | b, A plant breeder wants to produce only pink Japanese four o°clock flowers. Can he do so by crossing pink Japanese four o’clock flowers with white Japanese four o’elock plants? Use a Punnett square to support your answer. @ Be oe Cross Resulting phenotypes Possible? Be x ey 602 Pine No oo © SMH Unite. having 2 eyebrows is dominant o 4, Hair texture in humans is incompletely dominant. Curly hair plus straight hair gives you wavy hair. Also, ver one eyebrow. If two individuals are heterozygous for both traits, what is the probability of each phenotype in their future offspring? Parental gametes Key Parental genotypes Heroes We * AREY both con Ree Whe Stcaight ened G® © © lee * Uni-orws Cross Description and probability of each a possible Phenotype bs. weed 2o0us * UMEE Wee WMEE Ener. pear ee, bus “ie © Grd tite Utter. Whe thee (Ge) WEE Hike WWE bree (re) Wk hee hike Wee Traighkt, Zone! Ee 154) Ay, uaitows = & ‘Co: 26%) Jay, wartomo * (12.5%) eputerwa = (26%) 5. Remember that hair texture is incompletely dominant, (With a curly hair person that mates with a strait hair person resulting in wavy hair children). Widow’s peak is dominant to not having a window’s peak. Ifa couple has wavy hair and both do not have a widow’s peak, what is the phenotypic ratios of the children? Jou emo vrdouds Reale Key Parental genotypes Parental gametes ec tate Wane | "Roy GS) Strtighh x ee Widows Reak @® o Cross. «&) Ke) GD Behe Hho (5) how Nawis Description and probability of each _ possible phenotype oe zd (25a) Wha % (s02) ote 4 (s2) Codominance 1. In shorthorn cattle, the hybrid between red and white is roan, having red and white hairs intermingled. If'a roan is bred with a white, what will the phenotypic ratio be? Key ci ¢ ated OW CECt F roan coat Lot cms white at Parental genotypes co ecw Parental gametes ©O€ Q eo ()éc? ee’ Phenotypic description and Ratio + Vhtt Multip! les /Codominance Suppose a man who is homozygous for type A blood marries a woman with type AB blood. What blood types would you expect to find among their children? Parental genotypes Parental gametes Key TATE oe DLA] a aa [TAT + Type SB Yee gq re ®D E @) Cross. S Possible Blood types & & Tyee K oe Tyee * A (56% chonee fh, 2. Aman with type AB blood is mai who has type O blood. What should the legal judgment be? irried toa woman with type O and he questions the legitimacy of her child, Parental genotypes uM Th = tye AB Ls Ter ¢ Parental gametes WW ® ® Oe & Cy Tt Te & | Possible Blood types of children “Type A oe ha, [Type $ Tegal judgement The child ts mot WS 3. A child has blood type AB, and the mother has blood type A. a, What are the possible genotypes of the cl b. What is the genotype of the child? how the moe aPs Be vate we Der Oe z d. What could be the possible genotypes of the father? ©. Could the father be type ©? Explain. np ole twee Chitlc needs to ak Hho TS alee Carn sonendhere wis potter? TATA or CXL Seung nett oe that ee. child with type AB blood et re 4, Mrs, Doe and Mrs. Jones had babies at the same hospital at the same time, Mrs. Doe took home a girl and named her Nancy. Mrs. Jones received a boy and named him Richard, However, Mrs. Jones was sure she hhad had a girl and brought a law suit against the hospital. Blood tests showed the Mr. Jones was type O. Mrs. Jones was type AB. Mr. and Mrs. Does were both type A. Nancy was type B and Richard was type O. Head an exchange occurred? Explain! (Use Punnett squares for evidence to support your claim) AY s = ub Me ie, ae C - Seas TTS tie Dee Tet o TL ee ‘oe © Sine —— ri &) Ti eye O here Kor Type Tues x cr 0 On ose * Gu 4 Bichild MI’ cid pe quotkun ak “tho waserte. 5. Mike and Carol Brady are expecting their first child together. Mike, however, has noticed that Sam the Butcher has been hanging around the house at weird times and often when his lady friend Alice is not around, When baby Brady is born, Mike notices that its blood type is B+. Mike is concerned because he has AB- blood and Carol has O+. Sam the butcher has A+ blood. Is Mike just being silly and will they have this situation settled in 30 minutes, or will we get the “to be continued” message for paternity ne in ‘upcoming ae + (1 Re 3 Gas, auld oe ee Mike Brady i. (xAt* re a Be hg, fea he. Gra Basy OF (iLRe) 4 Covel co i Som Ke CINK) Caml x Mike Cool * Sau & @ © VGag) Tree TH¥e Tikh Tere Thee Tice Tr) FA i Thee Tire VG) vce Uke Resi lod types YO ice ae, As Rr, B* o¢ Be Ree Or oc O- i Linked Gene Problems 1, In the high-pressure, deep, dark depths of the ocean's abyssal plains lives an organism called a viper fish. These fish resemble transparent eels with overlarge heads and very long, pointy teeth. Because of where they live, very little is know about these fish but for the sake of this problem, we shall assume that some of them can produce biochemical lights along the length of their bodies and some cannot. In addition, some have very large eyes while some have almost no eye at all. Further, we shall assume that these two traits are each controlled by single locus genes with the production of lights and large eyes being the dominant alleles for each. Lastly, assume that these genes are linked closely on the same chromosome, It is very difficult in the vast expanses of the deep ocean for two viper fish to find each other, but suppose that a female heterozygous for both traits (the two dominant alleles are on one chromosome and the two recessive are on its homolog in this individual) happens to meet a male that is homozygous dominant for lights and homozygous recessive for eyes. What are the possible genotypes of their offspring? Key Parental genotypes (show with | Parental gametes @howadth Lo Lejats chromosomes), a) py 0 ) Li A Uagits Qe. f te Ge) Ee = Bis eyes fees ro eyes io? LLee it K ac) “@ © \® uke Ute Possible genotypes of offspring 50% LLEe 50% LL ee TOA Lights + caged 50% Lights no eupas A What are the possible phenotypes of the offspring of the cross above? 2. Snow leopards live in the high reaches of the Himalayas and have several adaptations to deal with living most of the time in snow. They have wide paws with hair between the toes to allow them to run on top of the snow crust. Assume that wide paws and hair between the toes are both dominant traits and are on the same chromosome. Suppose that two snow leopards, heterozygous for both traits, mate. Suppose further that in the female, the two dominant alleles are on the same chromosome of the homologous pair, while in the ‘male, each chromosome of the pair has one dominant and one recessive allele. What percentage of each genotype will be produced? tne Ho baie Key Parental genotypes (show with Parental gametes (show-with We = wide Paws chromosomes) : chromosomes) ow = Narra. por'S g Wolh y me @® ey LL = Hie oho foes i “@ an ‘Cross wee WW Woks Wall oath : 8 f f Description and probability of each possible phenotype oF Watlh Wide paws wf haic > (Son) ods paws no hic + (2s) Noriow pus hair a (25%) ‘What percentage of the offspring will have narrow paws with hair between the toes 3. Suppose you have a bunch of whit 24 ite mice, some that are only white and some with black spots. There are also some of your mice with black eyes and some with pink eyes. Assume that the genes for hair color and eye color are linked and that plain white is dominant to black spots and that black eyes are dor ant to pink eyes. You decide to cross a female that is homozygous dominant for hair color (you just happen to know the ‘genotype of each mouse since they’ve been in this lab breeding population for several generations) and heterozygous for eye color with a male that is heterozygous for both traits. In the male, each homologous chromosome contains a dominant and recessive allele from the two genes, What genotypic ratio do you expect in the offspring? Ail= dain white Loup 2 Wiad SPS YR WRB WBE Parental gametes fehow-with obvomosomes) (QB) @ (we) ® Genotypic description and ratiok WWBlo WIN *WsBB ¢ WB} pike Ved Parental genotypes (show with chromosomes} wy I@wuiee v ¥ What percentage of the offspring wil aCe ill have black spots and pink eyes? _ 4. A group of spiders known as orb weavers often construct patterns with threads visible in the ultraviolet spectrum into the centers of their webs. These pattems mimic the centers of flowers and provide a lure for unwary flying insects that can see in the ultraviolet range. Suppose that in a particular species of orb weavers, the gene controlling the type of pattern placed in the center of the web is linked to a gene controlling whether the spider has green spots. In this case, the allele for a UV pattem that is a solid circle is dominant to the allele for a UV pattern that is a target pattern, The allele for green spots is dominant to the allele for no spots. Suppose a female heterozygous for both traits (and with the dominant alleles of the two traits on one homologous chromosome and the recessive alleles on the other homolog) mates with a male that is homozygous recessive for pattern type and heterozygous for spots. What percentage of each phenotype will be found in the offspring? Parental genotypes (show with aegegm) Peo Sy VeGs te Parental gametes (show-with le Description and probability of each possible phenotype Sahid cece . 4 (

You might also like