Chapter 5, Problem 1CT

Scientists use the particular structure of nucleic acids and other chemical differences to separate the archaea from the bacteria. Can you think of other characteristics that could be used to distinguish not only between these two domains but also between them and protists?

Summary Introduction

To determine: The characteristics that distinguish archaea, bacteria, and protists.

Introduction: Biology is the scientific study of life and related biological aspects. In taxonomy of biological hierarchy, there is highest taxonomic rank of organism in a three-domain classification of taxonomy given by Carl Woese. The three domains of the biological hierarchy are archaea, bacteria, and eukarya. Prokaryotes are usually unicellular including bacteria and archaea, while eukaryotes are usually multicellular including protists, fungi, plants, and animals.

Explanation of Solution

Tabular representation: The characteristics that distinguish between archaea, bacteria, and protists other than nucleic acid structure and chemical differences are shown in Table 1.

Table 1: The characteristics that distinguish between archaea, bacteria, and protists

Criteria	Archaea	Bacteria	Protists
Nuclear envelope	It is absent in archaea.	It is absent in bacteria.	It is present in protists.
Membrane-enclosed organelles	Membrane-enclosed organelles are absent in archaea.	Membrane-enclosed organelles are absent in bacteria	Membrane-enclosed organelles are present in protists.
Peptidoglycan in cell wall	Peptidoglycan is absent in archaea.	Peptidoglycan is present in bacteria.	Peptidoglycan is absent in protists.
Membrane lipids	Some branched hydrocarbons are present in archaea.	Unbranched hydrocarbons are present in the bacteria.	Unbranched hydrocarbons are present in protists.