Read the passage and answer the question: 

Read the passage and answer the question: 
The metamorphosis of a butterfly epitomizes one of nature’s most intricate and captivating transformations. The life cycle initiates with the deposition of fragile eggs, often hidden on the underside of leaves, ensuring immediate access to nourishment upon hatching.
once emerged, the larva- or caterpillar – enters a phase of relentless consumption, devouring foliage to fuel its rapid growth. During this stage, it undergoes multiple molts, shedding its rigid exoskeleton to accommodate its expanding form. this insatiable feeding period is essential for amassing the energy required for the subsequent, dramatic metamorphosis.
The transition into the pupal stage, encapsulated within a chrysalis, marks an  extraordinary biological phenomenon. Inside, the caterpillar’s structures are enzymatically dismantled and reconstructed into entirely new forms – wings, antennae, and compound eyes emerge through a sophisticated process known as histogenesis.
Upon completing this hidden transformation, the adult butterfly struggles free, its crumpled wings needing to be inflated with hemolymph and dried before flight is possible. Once airborne, the butterfly’s existence centres on reproduction, perpetuating the species before its ephemeral life concludes.
Though often romanticized, the butterfly’s life cycle underscores a rigorous narrative of survival, adaptation, and evolutionary precision, offering profound insights into the fragile balance of ecosystems.

Which sentence  contains a relative clause?