Name: Period: Monohybrid Cross Video Review 1. What is the name of the little boxes used in order to predict offspring without having to breed? 2. Define Punnett Square: 3. Define a monohybrid cross: 4. Typically, where are the male vs. female alleles written on the Punnett square? 5. Describe the process needed to complete a Punnett square: 6. If a homozygous tall man and a heterozygous tall woman were to have a child, what are the possible genotypic and phenotypic ratios? 7. When diseases are tracked they are usually what type of diseases? 8. Define autosomal chromosomes: 9. What is an example of an autosomal disease? 10. Describe what happens to the individual who possess this disease: 11. If a woman s father had the disease, what would the probability of her having the disease be? Is it likely that the father was homozygous dominant? 12. Cystic Fibrosis is an autosomal recessive disease resulting in the body s production of excess mucous. What would the probability be for a couple who is heterozygous for the trait to have a child who is affected? 13. What s the chance of having a boy or girl? 14. Determine the genotype of the F1 generation when a heterozygous black rabbit is crossed with a homozygous brown (bb) rabbit. 15. White (W) hair is dominant over black (w) hair in sheep. A white male and a black female are parents of a black lamb. What is the probability that their next lamb will be white? 16. The offspring of two short-tailed cats have a 25% chance of having no tail, a 25% chance of having long tail, and a 50% chance of having a short tail. What can you hypothesize based on this information about the genotypes of the parents.
AMOEBA SISTERS: VIDEO RECAP MONOHYBRID CROSSES (MENDELIAN) Amoeba Sisters Video Recap: Monohybrid Crosses (Mendelian Inheritance) Vocabulary practice! Fill in missing boxes assuming that having hair for guinea pigs follows Mendelian inheritance, where the H dominant allele codes for hair and h codes for a lack of hair (hairless). Image Genotype Heterozygous or Homozygous? Phenotype HH 1. 2. 3. 4. Hairless 5. 6. Heterozygous 7. 8. An allele is a form of a gene. In the Punnett square on the right, how many H/h alleles does a baby guinea pig inherit from the mother? How many H/h alleles does a baby guinea pig inherit from the father?. If a baby girl guinea pig looks almost identical to its mother, does this then mean that it inherited more alleles from its mother? Explain. (Hint: Think about the vocabulary words dominant and recessive.)
AMOEBA SISTERS: VIDEO RECAP MONOHYBRID CROSSES (MENDELIAN) Mysterious Fred: A Guinea Pig Test Cross There is a teacher from Texas that loves hairless guinea pigs. In guinea pigs, the dominant allele H codes for the trait of having hair and the allele h codes for the trait of being hairless. (Assume Mendelian inheritance). Let s say that this teacher receives her wish of finding a hairless guinea pig at a pet store and names her Genevieve. She finds another guinea pig at a store with hair that she names Fred. While she can be certain of Genevieve s genotype, how could she determine what genotype Fred is? She can do a test cross! A test cross involves breeding an organism with a dominant trait (like Fred) with an organism that exhibits a recessive trait (like Genevieve). 9. Genevieve has the genotype. 10. Fred s genotype could be or. 11. If Fred was genotype and bred with Genevieve 12. Please draw Punnett Square below to show prediction for offspring. 13. If Fred was genotype and bred with Genevieve 14. Please draw Punnett Square below to show prediction for offspring. 15. Explain in your own words how the offspring from the test cross could help determine Fred s genotype. 16. What could be some weaknesses with using a test cross to determine Fred s genotype?
Name: Period: Ch 11 Genetics Problems 1. For each genotype, indicate whether it is heterozygous or homozygous: 2. For each of the genotypes below, determine the phenotype: 3. For each phenotype, list the genotypes. (Remember to use the letter of the dominant trait): 4. Set up the square for each of the crosses listed below. The trait being studied is round seeds (dominant) and wrinkled seeds (recessive): 1
Practice with Crosses. Show all work! 5. A TT (tall) plant is crossed with a tt (short plant). What percentage of the offspring will be tall? 6. A Tt plant is crossed with a Tt plant. What percentage of the offspring will be short? 7. A heterozygous round seeded plant (Rr) is crossed with a homozygous round seeded plant (RR). What percentage of the offspring will be homozygous (RR)? 8. In pea plants purple flowers are dominant to white flowers. If two white flowered plants are crossed, what percentage of their offspring will be white flowered? 2
Make your own Punnett squares in the space under the question. 1. Widow s peak is dominant to no widow s peak. Determine the genotype and phenotype ratios for a homozygous dominant female and a homozygous recessive male. 2. Dimples is dominant to no dimples. Determine the genotype and phenotype ratios for a heterozygous female and a homozygous dominant male. 3. Short hair is dominant to long hair in mice. Determine the genotype and phenotype ratios for a homozygous recessive female and a heterozygous male. 4. Cleft chin is dominant to no cleft chin. Determine the genotype and phenotype ratios for a heterozygous female and a heterozygous male. 5. Brown eyes are dominant to blue eyes. Determine the genotype and phenotype ratios for a homozygous dominant female and a homozygous dominant male. 3