The Mesozoic Era started about 225 million years prior to the present era, the amphibians were declining after a long period of supremacy among the animals and the reptiles were gradually replacing them. Many of them became very large fearsome and came to dominate the animal life practically everywhere. As a result, giant reptiles, dinosaurs, and other monstrous beasts become very abundant and spread into all habitats. For this reason, the Mesozoic era is also called the Age of Reptiles or the Age of Dinosaurs. Continue reading Mesozoic Era – the Age of Reptiles.
The Kingdom Protista includes diverse kinds of predominantly water-dwelling unicellular eukaryotic microorganism. Protists, like Monerans, have an immense reproductive potential. In an optimal environment, they may reproduce several times a day. This is mainly by asexual reproduction, using the process of mitosis. However, they also reproduce sexually. Continue reading Sexual Reproduction – An Important Innovation of the Early Protists.
In 1868, T. H. Huxley described protoplasm as the “physical basis of life”. Protoplasm is a clear, colorless and jelly-like substance which seemed to make up the contents of the cell. It was also described as “substance of life” or “living material”. Continue reading What is the physical basis of life?
It is a well-known fact that DNA acts as a genetic material in most of the organisms on this planet earth. However, it is also clear that RNA also acts as a genetic material, but only in some viruses (for example, Tobacco Mosaic Viruses, QB Bacteriophage, etc.).
Continue reading Why Nature Preferred DNA over RNA?
The origin of new species from the existing one is called Speciation. It occurs when a group within a species migrates to a new area with different environmental conditions and develops its own unique features. Speciation has taken place over the course of evolution and may have played an important role in driving biodiversity on planet Earth. Continue reading What is Speciation?