CAIE IGCSE Biology 17.4.11 Genetic Diagrams to Predict Questions

Practise using genetic diagrams to predict monohybrid cross results and calculate 1:1 or 3:1 phenotypic ratios.

Syllabus
2026–2028
Course
Biology 0610

Exam points

  • use genetic diagrams to predict the results of monohybrid crosses
  • calculate phenotypic ratios limited to 1:1 and 3:1

CAIE IGCSE Biology 17.4.11 Genetic Diagrams to Predict Questions question 1

[Maximum number: 2]

Fig. 2.1 shows a dwarf sunflower and a tall sunflower, Helianthus annuus. The height of the dwarf sunflower is 0.45 m and the height of the tall sunflower is 4.5 m .

not to scale

not to scale

Dwarf plants like the one in Fig. 2.1 have mutant alleles.

Two tall sunflower plants were crossed. 25\% of the offspring produced were dwarf.

Explain how it is possible for two tall parent plants to have this percentage of dwarf offspring.

All question bank results loaded