Q85 - Complementation Analysis of Three White-Flowered Mutant Lines
A plant is normally red-flowered. Plant breeders obtained three genetically different pure mutated lines of white-flowered plants (designated as a, b and c). They performed crosses and observed progeny phenotypes as follows:
| Cross | Parents | Progeny |
|---|---|---|
| 1 | line a × line b | F1 all white |
| 2 | line a × line c | F1 all red |
| 3 | line b × line c | F1 all white |
| 4 | red F1 from cross 2 × line a | 1/4 red : 3/4 white |
| 5 | red F1 from cross 2 × line b | 1/8 red : 7/8 white |
| 6 | red F1 from cross 2 × line c | 1/2 red : 1/2 white |
Indicate in the answer sheet if each of the following statements is true or false.
Using the information and data, determine which of the statements are true or which are false.
A. Line (a) has only one homozygous mutated gene.
B. Line (b) shares two homozygous mutated genes with line c.
C. Line (c) shares one homozygous mutated gene with line a.
D. Line (b) has three homozygous mutated genes.
Question reproduced from IBO 2016, Theoretical Paper B, licensed under CC BY-NC-SA 4.0 - attributed to the International Biology Olympiad. Open the full exam PDF · Community solutions (unofficial)