So let’s start-off with Monera. Monera. I already swam you through them a bit. They are the prokaryotes – meaning that they do not have well defined nucleus. They have two sub types: the bacteria and the Archaea. Bacteria are like everywhere. I hate to break this tube but there is more single celled organisms than human beings on this planet. They actually invario… in a nice way actually. They form 80 % of the cells in your body. And don’t worry! They are actually ok to have around, occasionally useful as well as they hang out in your digestive system and aid the digestion. For example, some of them also help in fixing nitrogen which is super useful to plants and helps them manufacture food. And then some of them are really harmful and can cause some diseases.
Archaea and Bacteria are called prokaryotes as I mentioned before. Because prokaryotic means before nucleus. And true to the name they do not have a well-defined nucleus. In fact, they do not have any organs at all but they do have genetic information in the form of DNA and RNA.
And yes, they came before the eukaryotes. And it’s the fact that all life from the planet has evolved from the prokaryotes. And our oldest, weirdest relatives are Archaea. Nothing takes back more than Archaea. Stages which have been found 3.8 billion years ago. This is just a billion year after years have formed and the planet was bombarded with comets and meteors, UV radiations stuff and still you had the archaea hanging out there as if nothing ever happened. The earth has calmed down a lot. Since then an archaea actually misses all these violence and because of that they still found the most extreme forms of environment on earth including volcanic hot springs, oil wells in deep down the ocean in hydrothermal effects.
One type of archaea infact is found in the temperature of 113 degree centigrade. Not Fare height, Celsius. Because 100 degree centigrade is actually you know the temperature water boils at. Bacteria are as widespread as archaea but not that ancient. The record show them to be around 1.5 billion years ago but some records are also there that were there 3 billion years. They are also super super adaptable and come in so many shapes sizes and colors: rods, cylindrical, circles, coils. You have bacteria, you actually have them all. Some of them are parasitic, which means that they are going to give you a really really tough time by causing diseases and make you immediately run for the antibiotic. And since there are so many types of bacteria, scientist have come up with the basic way of classifying them based on the way the cell membrane react with stain called the Gram stain.
So one type of bacteria with thick wall because gram positive bacteria has a huge group which streptococcus, staphylococcus, bacilli, clostridium, and listed here are few and they are responsible for deadly diseases like leprosy and tuberculosis.
And then you have the gram negative bacteria which have thin walls, which do not stain with gram stain. They help fix nitrogen in the atmosphere and help the plants grow and then there are some which actually cause food poisoning. Cyanobacteria are the only bacteria that use photosynthesis to make their own food. And since they are such ancient forms, they look alien like and not really like life the way you think about it.
These guys are so adaptable and it’s probably their adaptability that has allowed them to hang around for so many years. But you know what…there is no denying it but all multi-cellular organisms like banyan tree or lion cub or the zebra or you and me have all descendant from this unicellular organism long…long…long time before and they haven’t changed much in the last few billion years they have liked they look and well settled down the generations that way and did not feel the need to change. Some of them evolved for millions and millions of years and formed multi-cellular organism and that’s what we will look at it today. We will climb up that revolutionary ladder together and see where exactly all these changes happened and how we all have actually come into being.