Chapter 18, Problem 14A

Summary Introduction

To determine:

The difference in the modern life on earth if the cyanobacteria were never evolved in the past.

Introduction:

The bacteria are the single cellular prokaryotic organism. They lack a true nucleus and have a very simple cellular design. They are known to be existing since life begin on the earth. Some of the bacteria are free-living, but many of them are parasitic and commensal in nature. Cyanobacteria one of such bacteria that have capability to perform photosynthesis and some of them can also perform nitrogen fixation.

Explanation of Solution

In the past, the cyanobacteria were the only organism which have ability to reduce the carbon and nitrogen present in the atmosphere. This helped the bacteria to evolve and give rise to different types of photosynthetic organism.

In case, the cyanobacteria would not have been evolved in past, the plant species would not have existed. Even if somehow, they managed to evolve, the evolution processes have been very slow, and there is no chance that modern life could have been in so much diverse form. The species evolution and diversity would have been very less and many of species, including humans would have never existed.