Papers | Singapore Junior Biology Olympiad Past

(c) If 320 offspring are produced, how many are expected to have purple flowers and pointed leaves? Show your working. (2 marks)

A plant with purple flowers and round leaves (heterozygous for both traits) is self-crossed.

(a) List two structural adaptations of the alveolus that maximize gas exchange. (2 marks) singapore junior biology olympiad past papers

(d) Name the principle illustrated by the independent assortment of these two genes. (1 mark)

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). (c) If 320 offspring are produced, how many

(a) State the genotype of the parent plant. (1 mark)

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. (a) List two structural adaptations of the alveolus

The diagram (described in text) shows a cross-section of a human lung alveolus and a fish gill filament.

(b) Using a Punnett square or branch diagram, determine the phenotypic ratio of the offspring. (4 marks)

(b) Explain the concept of countercurrent exchange in fish gills and explain why it is more efficient than concurrent flow. (4 marks)