A student uses a respirometer to measure oxygen consumption in crickets at 20°C and 30°C.
(b) Explain the concept of countercurrent exchange in fish gills and explain why it is more efficient than concurrent flow. (4 marks)
(b) Predict the relative rate of oxygen consumption at 30°C vs 20°C. Explain your answer in terms of enzyme kinetics and metabolic rate. (3 marks)
(a) List two structural adaptations of the alveolus that maximize gas exchange. (2 marks) singapore junior biology olympiad past papers
A plant with purple flowers and round leaves (heterozygous for both traits) is self-crossed.
In Arabidopsis thaliana , flower color is controlled by a single gene with two alleles: Purple (P) dominant over white (p). Another unlinked gene controls leaf shape: Round (R) dominant over pointed (r).
Below is a structured set of original questions (Section A: Multiple Choice, Section B: Structured/Free Response), followed by a detailed answer key and performance analysis guide. Subject: Junior Biology Olympiad Time: 1 hour 30 minutes (simulated) Total Marks: 60 Section A: Multiple Choice (30 marks) Questions 1 to 15. Each correct answer earns 2 marks. Select the single best answer. A student uses a respirometer to measure oxygen
(d) Name the principle illustrated by the independent assortment of these two genes. (1 mark)
(a) State the genotype of the parent plant. (1 mark)
(b) Using a Punnett square or branch diagram, determine the phenotypic ratio of the offspring. (4 marks) Explain your answer in terms of enzyme kinetics
This is a development of modeled exactly on the style and difficulty of the Singapore Junior Biology Olympiad (SJBO) . Since actual past papers are copyrighted, this serves as a faithful simulation for training.
(c) The student forgot to include a control vial with glass beads (no crickets). Explain why a control is necessary. (2 marks)