Living Environment Regents Practice Test

How do green sea slugs acquire the ability to photosynthesize?

1. From consuming algae that contains chloroplasts

2. From their symbiotic relationship with microorganisms

3. From inherent genetic traits

4. From exposure to sunlight only

The correct answer is: From consuming algae that contains chloroplasts

Green sea slugs, specifically the Elysia chlorotica species, acquire the ability to photosynthesize primarily through the consumption of algae that contain chloroplasts. When these slugs eat the algae, they incorporate the chloroplasts from the algal cells into their own tissues, a process known as kleptoplasty. The retained chloroplasts remain functional within the slug's cells, allowing it to capture sunlight and convert it into energy through photosynthesis, much like plants. The other options provide alternative concepts related to photosynthesis and organism interactions but do not accurately describe the primary method by which green sea slugs acquire this capability. While symbiotic relationships with microorganisms and inherent genetic traits could explain certain aspects of energy acquisition or adaptations in other organisms, they do not specifically apply to the mechanism through which green sea slugs utilize photosynthesis. Exposure to sunlight alone does not impart the ability to photosynthesize without the crucial components obtained from the algae, reinforcing the importance of the consumption process in their unique adaptation.