10 Spot size on ladybugs is controlled by one gene In a
Last updated: 12/13/2022
10 Spot size on ladybugs is controlled by one gene In a certain population of ladybugs you observe some individuals with small spots other individuals with medium spots and still other individuals with large spots You breed two homozygous ladybugs one ladybug has small spots and the other ladybug has large spots All the offspring from this cross cross 1 have medium spots Based on this result you hypothesize that the alleles that affect spot size are interacting in a particular way To test this hypothesis you take two of the offspring from cross 1 with medium spots and breed them From this second cross cross 2 you get 54 ladybugs with small spots 120 ladybugs with medium spots 46 ladybugs with large spots Use this information to answer the following questions Formatting rules for numerical answers enter probabilities as frequencies for example 0 14 enter numbers of individuals as whole numbers for example 5 round chi square values category values and test statistic to the hundredth decimal place for example 0 76 The DOMINANT phenotype s is are Medium spots The RECESSIVE phenotype s is are Small spots Large spots The most logical hypothesis is the alleles are interacting through incomplete dominance If the alleles are interacting in the way that you hypothesize then the probability of getting offspring with SMALL spots from cross 2 is 0 25 The probability of getting offspring with MEDIUM spots is 0 50 The probability of getting offspring with LARGE spots is 0 25 The probability of getting offspring with a combination of LARGE AND SMALL spots is 0 0 From cross 2 the expected number of offspring with SMALL spots is 55 The chi square value for this category is 0 02 The expected number of offspring with MEDIUM spots is 100 The chi square value for this category is The expected number of offspring with LARGE spots is 55 The chi square value for this category is 1 47 The chi square test statistic for this experiment is 4