Discuss one example, based on your day-to-day observations, showing how loss of one species may lead to the extinction of another.

Explanation

Co-extinction is the extiction of two mutually related or interelated specials for instance a host fish extinction leads to the extinction of all those parasites exclusively found on it. Another example is plant pollinator mutualism, where extinction of one leads to the extinction of other.
Insect, aphids are polyphagous (feed on more than one plant species) or monophagous (feed on a particular species of plant). Monophagous insects may becomes extinct, if the plant species upon which they feed becomes extinct.