Question

A lichen is an organism that structurally appears to be a single organism. But a lichen is actually two different organisms—a fungus and green algae—living together as one organism. The fungal partner derives its nutrition from the photosynthesizing algae. How does a lichen differ in its photosynthetic activity from Elysia chlorotica, the sea slug that’s considered to be a photosynthesizing animal?

Answer 1

Lichens are a symbiotic association between a fungus and an algae or a cyanobacterium. The fungus benefits from the photosynthetic activity of the algae or cyanobacterium, while Elysia chlorotica, the sea slug, incorporates chloroplasts from algae to perform photosynthesis.

Step-by-step explanation:

Lichens are a symbiotic association between a fungus and an algae or a cyanobacterium. The fungus provides support and protection while the photosynthetic partner provides energy through photosynthesis. This relationship is considered to be a controlled parasitism, as the fungus benefits while the photosynthetic organism is harmed to some extent.

In contrast, Elysia chlorotica, the sea slug, is considered a photosynthesizing animal. It consumes algae and incorporates their chloroplasts into its own cells through a process called kleptoplasty. The slug then uses the chloroplasts to perform photosynthesis and produce its own energy.

Answer 2

Lichens can photosynthesize only because of the living algal partner, while Elysia chlorotica incorporates chloroplasts from algae into its cells.