Chapter 26.1, Problem 3R

Summary Introduction

To review:

The reason as to why the ribosomal ribonucleic acid (rRNA) genes of chloroplast, nucleus, and mitochondria are not closely related in corn.

Given:

Gene tree showing the evolutionary relationship among rRNA gene sequences from nuclear genomes of human, corn, prokaryotic Archaean, a proteobacterium, cyanobacterium, mitochondrial, and chloroplast genomes.

Introduction:

According to the endosymbiotic theory, certain cellular organelles such as mitochondria and chloroplasts are descendants of prokaryotic cells engulfed by an ancestor eukaryote. These bacteria-resisted digestion became part of the modern eukaryotic cell and performed vital functions of the cell such as oxidative phosphorylation and photosynthesis.