Chapter 20, Problem 1RC

Summary Introduction

To draw: Basic structure of phylogenetic tree of life on the basis of SSU rRNA sequences and also determine the placement of Archaea.

Introduction: Phylogenetic tree refers to a diagram representing the evolutionary relatedness among the living organisms. One of the methods of construction of phylogenetic tree includes comparing small subunit (SSU) ribosomal ribonucleic acids (rRNAs) molecules.

Explanation of Solution

Pictorial representation: Figure 1 represents phylogenetic tree of life-based on SSU rRNA.

Fig.1: Phylogenetic tree of life

In order to form a phylogenetic tree, one method of classifying organisms include aligning and comparing the nucleotide sequences present in the gene that encode SSU rRNAs. The difference in the nucleotide sequence of the organisms indicates the evolutionary distance. In phylogenetic tree, Archaea, Bacteria, and Eukarya diverge from one point and then branch off.