Storage products — Starch as the primary energy reserve is characteristic of which algal division?

Introduction / Context:
Energy storage compounds are central to algal systematics. Different divisions store photosynthate in distinct forms, and this biochemical fingerprint helps separate major groups.

Given Data / Assumptions:

• Chlorophyta (green algae) store as starch within chloroplasts, similar to land plants.
• Chrysophyta sensu lato (including diatoms, golden algae) store as chrysolaminarin or oils.
• Phaeophyta (brown algae) store laminarin and mannitol.
• Rhodophyta (red algae) store floridean starch (distinct from plant starch).

Concept / Approach:
Among the options, classic “starch” as in green lineages is associated with Chlorophyta. Though Rhodophyta have floridean starch, the conventional match for “starch” in basic MCQs is Chlorophyta.

Step-by-Step Solution:

Verification / Alternative check:
Biochemistry texts and phycology keys list starch for green algae and laminarin/mannitol for brown algae.

Why Other Options Are Wrong:

• Chrysophyta: chrysolaminarin/oils.
• Phaeophyta: laminarin/mannitol.
• Rhodophyta: floridean starch (chemically distinct from plant starch).

Common Pitfalls:
Confusing floridean starch with plant-like starch; exam convention points to Chlorophyta.

Final Answer:
chlorophyta