Concept explainers
The genes for the trails that Mendel worked with are either all located on different chromosomes or behave as if they were. How did this help Mendel recognize the principle of independent assortment?
a. Otherwise, his dihybrid crosses would not have produced a 9:3:3:1 ratio of F2
b. The occurrence of individuals with unexpected phenotypes led him to the discovery of recombination.
c. It led him to the realization that the behavior of chromosomes during meiosis explained his results.
d. It meant that the alleles involved were either dominant or recessive, which gave 3:1 ratios in the F1 generation.

Introduction:
The principle of independent assortment states that the genes coding for different traits is passed on to the next generation independent of each other. This law of independence assortment holds true only in the case where the two pairs of characters are coded by genes that are present on two different chromosomes.
Answer to Problem 1TYK
Correct answer:
In case the genes for the trait would have been on the same chromosome, the ratio in the F2 generation would have been other than 9:3:3:1.
Explanation of Solution
Explanation/Justification for the correct answer:
Option (a) is given as the pairs are independently assorted the progeny can have different phenotypes. In case the genes are present on the same chromosome, they might show some degree of linkage. Furthermore, the presence of the genes on the same chromosome would have resulted in crossing over and alteration of the ratio of the F2 generation. Hence, Option (a) is correct.
Explanation for incorrect answers:
Option (b) is given as the discovery of the recombination as a result of the occurrence of the individuals with unexpected phenotypes. However, the process of recombination was discovered by the experiments conducted by Thomas Hunt Morgan and his colleagues on Drosophila. So, this is the wrong answer.
Option (c) is given as the results obtained during meiosis were due to the behavior of chromosomes. Mendel believed that the determinants of heredity never show blending and never gets modified. So, this is the wrong answer.
Option (d) is given as the 3:1 ratio in the F1 generation signifying that the alleles involved were either dominant or recessive. The principle of the independent assortment was introduced because of the dihybrid cross. So, this is the wrong answer.
Hence, options (b), (c), and (d) are incorrect.
Thus, the location of the chromosomes for the genes with which Mendel worked resulted in the unexpected phenotypes that helped him in recognizing the principle of independent assortment.
Want to see more full solutions like this?
Chapter 14 Solutions
Biological Science (7th Edition)
- Which of the following best describes why it is difficult to develop antiviral drugs? Explain why. A. antiviral drugs are very difficult to develop andhave no side effects B. viruses are difficult to target because they usethe host cell’s enzymes and ribosomes tometabolize and replicate C. viruses are too small to be targeted by drugs D. viral infections usually clear up on their ownwith no problemsarrow_forwardThis question has 3 parts (A, B, & C), and is under the subject of Nutrition. Thank you!arrow_forwardThey got this question wrong the 2 previous times I uploaded it here, please make sure it's correvct this time.arrow_forward
- This question has multiple parts (A, B & C), and under the subject of Nutrition. Thank you!arrow_forwardCalculate the CFU/ml of a urine sample if 138 E. coli colonies were counted on a Nutrient Agar Plate when0.5 mls were plated on the NA plate from a 10-9 dilution tube. You must highlight and express your answerin scientific notatioarrow_forwardDon't copy off the other answer if there is anyarrow_forward
- Human Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage LearningBiology: The Dynamic Science (MindTap Course List)BiologyISBN:9781305389892Author:Peter J. Russell, Paul E. Hertz, Beverly McMillanPublisher:Cengage LearningBiology Today and Tomorrow without Physiology (Mi...BiologyISBN:9781305117396Author:Cecie Starr, Christine Evers, Lisa StarrPublisher:Cengage Learning
- Biology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStaxConcepts of BiologyBiologyISBN:9781938168116Author:Samantha Fowler, Rebecca Roush, James WisePublisher:OpenStax CollegeHuman Biology (MindTap Course List)BiologyISBN:9781305112100Author:Cecie Starr, Beverly McMillanPublisher:Cengage Learning





