Q38 — Chemical A, Gibberellin, and Wheat Seed Germination

Theoretical B Real exam question — full text reproduced under IBO's CC BY-NC-SA 4.0 license

Kazakhstan is one of the significant contributors to global wheat production and export. Researchers at Kazakh National University studied how chemical A affects wheat (T. aestivum) development.

Two-panel figure: panel A shows photographs comparing seed and isolated-embryo germination with and without chemical A (Ch-A) treatment; panel B shows a zymogram gel with bands for control, Phyt-X, and Phyt-X-with-Ch-A treatments, where dark bands indicate starch digestion by α-amylase. Figure 1. A The impact of chemical A (Ch-A) on the germination of seeds and isolated embryos (C: control). B The effect of chemical A on α-amylase activity in seeds (C: control). Briefly: wheat embryos were treated with chemical A and/or phytohormone X (Phyt-X), then total proteins were extracted and separated by polyacrylamide gel electrophoresis (PAGE). The gel was immersed in starch solution, then iodine solution was added — iodine reacts with starch to produce a dark black color and prevents a bright white color from appearing (as in panel B); glucose does not react with iodine.

On your answer sheet, indicate “T” for true statements and “F” for false ones.

A. Adding chemical A to the soil can reduce wheat cultivation time.

B. The seed coat to some extent imposes a barrier for chemical A.

C. In Figure 1B, the phytohormone X is more likely to be abscisic acid than gibberellin.

D. In Figure 1B, proteins are denatured and linearized before running PAGE.

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Question reproduced from IBO 2024, Theoretical Exam Part B, licensed under CC BY-NC-SA 4.0 — attributed to the International Biology Olympiad. Open the full exam PDF