The hoverfly and the wasp are insects with bright yellow and black markings. The wasp has a sting to defend itself against predators, but the hoverfly does not have a sting. Hoverflies and wasps live in the same habitat.

Explain how having yellow and black markings helps the hoverfly survive.

This is an example of Batesian mimicry. The wasp is a "model" species that has a genuine defence mechanism (a sting) and advertises it with warning colouration (aposematism). Predators that try to eat a wasp get stung and learn to associate the bright yellow and black pattern with a painful experience. The hoverfly is a "mimic" species. It is harmless but has evolved to look like the dangerous wasp. Predators, having learned to avoid wasps, will also avoid hoverflies, granting the hoverfly protection from predation. This increases its fitness, meaning it is more likely to survive and pass on its genes.