Cambridge Secondary (7-9). Stage 9. MCE Science. Workbook - Unit 3: Variation and Inheritance - Question 59

Study the food web of a rocky shore. Arrows point from food to the organism that eats it. Rising sea temperatures due to global warming caused the extinction of the periwinkle snail in this scenario. There was no significant effect of the extinction of the periwinkle snails on the gull population. Explain why this is so.