Dr. Bio samples some pond water to observe under the microscope. She finds the specimen above, which seems to have a clear shell or wall with yellowish pigmentation within. No flagella or cilia are observed. Recognizing that this is clearly a unicellular organism, Dr. Bio's best guess as to its classification is:

His best guess to it's classification is a Diatom

diatoms

Explanation:diatoms are aquatic algae which may live in marine and freshwater environment.they are golden brown.they can occurs as floating or dwelling in the bottom of the water body.

Diatoms are unicellular and they posses cell walls composed of pectin and silica deposits.they occur in varying shape.each half of its cell is called a valve and the whole cell is called a frustule.

Diatoms may have one or many chloroplast which contains chlorophyll,carotenoids and xanthophyll.thus makes the organism appear golden or yellow in colour.

They are primary producers and are easily fossilized to form diatomaceous earth.

protein synthesis is an example of feedback mechanism which in homeostasis