A. Porphyra is an algae plant with chloroplasts, which can carry out photosynthesis and autotrophic. A is correct;

B, locusts are animals, there is no chloroplast in cells, and they feed on ready-made organic matter, which belongs to heterotrophy. B error;

C Penicillium belongs to fungi, and there is no chloroplast in the body, which is saprophytic and heterotrophic. C error;

D Penicillium belongs to fungi, and there is no chloroplast in the body, so it is saprophytic and heterotrophic. D error.

So choose: a