The organism that can carry out both autotropic and heterotrophic modes of nutritions is

Step 1: Analyze the question The question asks which organism can feed both autotrophically (making its own food, usually by photosynthesis) and heterotrophically (taking in ready-made food). Organisms that do both are called mixotrophs.

Step 2: The concept

• Autotrophic nutrition: the organism has chlorophyll and makes food by photosynthesis.
• Heterotrophic nutrition: the organism feeds on organic matter made by others, by ingestion or absorption.
• Euglena is the classic example of an organism with both modes of nutrition.

Step 3: Go through the options

• A. Chlamydomonas: a green alga with chloroplasts. It is mainly autotrophic. It can take up acetate in the dark, but it is not the standard textbook example for this question.
• B. Eudorina: a colonial green alga that is purely autotrophic.
• C. Euglena: in the presence of light, it photosynthesizes using its chloroplasts (autotrophic). In the dark, or when light is lacking, it absorbs dissolved organic nutrients or ingests food particles (heterotrophic). It has a flexible body, a flagellum, and an eyespot, and it shows features of both plants and animals.
• D. Spirogyra: a filamentous green alga with spiral chloroplasts. It is purely autotrophic.

Step 4: Answer The organism that can carry out both autotrophic and heterotrophic nutrition is Euglena, which is option C.

Exam tip: Remember "Euglena = Even both". Whenever WASSCE, NECO or JAMB asks about an organism that is both plant-like and animal-like, or feeds in both ways, think of Euglena first. Spirogyra, Eudorina and Chlamydomonas are the "green algae that only make their own food" group.