You have an organism with the following characteristics - it grows as single cells. It is heterotrophic and has a cell wall that does not contain peptidoglycan. What are the possible identities for this organism? What other information do you need to know about it in order to get a definitive identification

Yeast or archaea

presence/absence of nucleus and membrane-bound organelles.

Explanation:

A unicellular organism that is heterotrophic with cell walls that lack peptidoglycan could be a yeast or an archaea.

Archaea, even though could be autotrophic or heterotrophic grows as single cells and their cell walls lack peptidoglycan.

Yeasts represents a group of unicellular fungi. They are also heterotrophic and lacks peptidoglycan in their cells walls (they have chitin instead).

In order to arrive at a more definitive identification, an information about the presence or absence of nucleus and other membrane-bound organelles will suffice.

Archaea do not have nucleus and membrane-bound organelles while yeast cells have both attributes.

Halophiles of Archaea domain

Explanation:

The Archaea are characterized as single cells. They can exihibit both the autotrophic and heterotrophic mode of nutrition. Their cell walls do not contain peptidoglycans but contain pseudo-peptidoglycans etc. Their environmental conditions also need to be known to give a definitive identification and also are their organelles membrane bound.