Simple Genetics Practice Remote Edition Key-1

Genetics Practice Problems (Remote Edition) 1. For each genotype below, indicate whether it is heterozygous (He) or homozygous (Ho) AA __Ho___ Pp __He___ Ee __He___ gg __Ho___ Bb _He____ Dd _He____ ff __Ho___ HH __Ho___ 2. For each of the genotypes below determine what phenotypes would be possible. Purple flowers are dominant to white Brown eyes are dominant to blue PP __purple__ Pp __purple___ pp __white___ BB __brown___ Bb __brown___ bb ___blue___ 3. For each phenotype below, list the genotypes (remember to use the letter of the dominant trait) Straight hair is dominant to curly Tail spikes are dominant to plain tails __HH___ straight __TT___ spikes __Hh___ straight __Tt___ spikes __hh___ curly __tt___ plain *Letters chosen can vary 4. Complete the Punnett squares for each of the crosses listed below. Tall (T) plants are dominant to short (t). Tt x tt _T_ _t_ _t_ Tt tt _t_ Tt tt What percentage of the offspring are tall? __50___ short? __50___ Tt x Tt _T_ _t_ _T_ TT Tt _t_ Tt tt What percentage of the offspring are tall? _75____ short? _25____ 5. A homozygous tall plant is crossed with a short plant. _T_ _T_ _t_ Tt Tt _t_ Tt Tt What percentage of the offspring are tall? __100___ short? __0___ 6. In pea plants, purple flowers are dominant to white. Complete the chart showing the genotypes and phenotypes possible Genotype Phenotype PP purple Pp purple pp white 7. A heterozygous purple flowered plant is crossed with one that is white. _P_ _p_ _p_ Pp pp _p_ Pp pp What percentage of the offspring are purple? __50___ white? __50___ 8. Two heterozygous purple flowered plants are crossed. _P_ _p_ _P_ PP Pp _p_ Pp pp What percentage of the offspring are purple? __75___ white? __25___ 9. In guinea pigs, the allele for short hair is dominant to long hair. What genotype would a heterozygous short haired guinea pig have? ___Hh__ What genotype would a homozygous short haired guinea pig have? __HH___ What genotype would a long-haired guinea pig have? __hh___ Show the cross for two heterozygous guinea pigs. _H_ h _H_ HH Hh _h_ Hh hh What percentage of the offspring will have short hair? __75___ long hair? ___25__ 10. Also in guinea pigs curly hair is dominant to straight. Show the cross between two homozygous curly haired guinea pigs _H_ _H_ _H_ HH HH _H_ HH HH What percentage of the offspring will have curly hair? __100___. 11. Punnett squares can also be used to predict genotypes of the parents. A guinea pig with short hair is crossed to one that has long hair. Over a period of years, a scientist keeps records of the offspring and finds that 44 of them have curly hair and 46 of them have straight hair. Based on this data, what are the genotypes of the parents: __Hh___ x __hh___ Show the Punnett square of this cross to explain your reasoning. _H_ _h_ _h_ Hh hh _h_ Hh hh 12. In another laboratory, a short haired guinea pig is crossed with a long haired one, and over the course of several years, not a single offspring has long hair. Show the cross that explains this situation. _H_ _H_ _h_ Hh Hh _h_ Hh Hh Genetics Practice Problems (Remote Edition) 1. For each genotype below, indicate whether it is heterozygous (He) or homozygous (Ho) AA _____ Pp _____ Ee _____ gg _____ Bb _____ Dd _____ ff _____ HH _____ 2. For each of the genotypes below determine what phenotypes would be possible. Purple flowers are dominant to white Brown eyes are dominant to blue PP _____ Pp _____ pp _____ BB _____ Bb _____ bb _____ 3. For each phenotype below, list the genotypes (remember to use the letter of the dominant trait) Straight hair is dominant to curly Tail spikes are dominant to plain tails _____ straight _____ spikes _____ straight _____ spikes _____ curly _____ plain 4. Complete the Punnett squares for each of the crosses listed below. Tall (T) plants are dominant to short (t). Tt x tt _T_ _t_ __ __ What percentage of the offspring are tall? _____ short? _____ Tt x Tt __ __ __ __ What percentage of the offspring are tall? _____ short? _____ 5. A homozygous tall plant is crossed with a short plant. __ __ __ __ What percentage of the offspring are tall? _____ short? _____ 6. In pea plants, purple flowers are dominant to white. Complete the chart showing the genotypes and phenotypes possible Genotype Phenotype 7. A heterozygous purple flowered plant is crossed with one that is white. __ __ __ __ What percentage of the offspring are purple? _____ white? _____ 8. Two heterozygous purple flowered plants are crossed. __ __ __ __ What percentage of the offspring are purple? _____ white? _____ 9. In guinea pigs, the allele for short hair is dominant to long hair. What genotype would a heterozygous short haired guinea pig have? _____ What genotype would a homozygous short haired guinea pig have? _____ What genotype would a long-haired guinea pig have? _____ Show the cross for two heterozygous guinea pigs. __ __ __ __ What percentage of the offspring will have short hair? _____ long hair? _____ 10. Also in guinea pigs curly hair is dominant to straight. Show the cross between two homozygous curly haired guinea pigs. __ __ __ __ What percentage of the offspring will have curly hair? _____. 11. Punnett squares can also be used to predict genotypes of the parents. A guinea pig with short hair is crossed to one that has long hair. Over a period of years, a scientist keeps records of the offspring and finds that 44 of them have curly hair and 46 of them have straight hair. Based on this data, what are the genotypes of the parents: _____ x _____ Show the Punnett square of this cross to explain your reasoning. __ __ __ __ 12. In another laboratory, a short haired guinea pig is crossed with a long haired one, and over the course of several years, not a single offspring has long hair. Show the cross that explains this situation. __ __ __ __