Biogeochemical Cycle

Biogeochemical cycle refers to the flow of an elements in nature between the organisms and the environment. This flow is cyclic and consistent. Elements within these cycles flow in various forms from the nonliving (abiotic) components of the biosphere to the living (biotic) components and back. Biogeochemical cycle is also known as inorganic-organic cycle. The … Read More


The outbreak of the Coronavirus disease 2019 (COVID-19 for short) has created a global health crisis (Figure 1). Not only do the high infection rates threaten the survival of millions, but the safety measures necessary to fight it also create a crisis in mental health and erode our sense of well-being. This course covers introduction … Read More

Structure of the Earth

To study seismic waves, topographic maps, plate tectonics, we should know the structure of the earth. Earth is the only planet known to have an atmosphere containing free oxygen, oceans of water on its surface, and life. This course covers the following: the structure of the earth  seismic waves topographic maps Structure of the Earth … Read More

Vaccines for COVID-19

More than a hundred different teams of scientists are developing vaccines for COVID-19. Developing vaccines from scratch is not the fastest option for stopping the ongoing pandemic no matter how effective they will be, but it is does constitute the desirable long-term solution. The time required to develop and deploy a safe and effective vaccine … Read More


Bacteria, (singular: Bacterium) are the simplest microscopic prokaryotes that belong to the Kingdom Monera. They lack membrane-bound nucleus and internal organelles. Bacteria live in a variety of habitats such as the soil, the ocean, and even the insides of the human gut. They exist either as free-living organisms or as parasites. These are most successful … Read More


Algae are a diverse group of undifferentiated aquatic organisms that contain chlorophyll. They range in size from microscopic organisms to giant kelp. They are important as primary producers and provide oxygen for other aquatic life. Algae are plant-like organisms that are photosynthetic and aquatic, with simple reproductive structures, but do not have true roots, stems, … Read More

Chemical Reaction

A chemical reaction is a process that involves rearrangement of the molecular or ionic structure of a substance. This involves breaking or formation of bonds between the atoms or ions. This course covers examples of chemical reaction , types of chemical bonds, and types of chemical reaction. When we hear the word chemistry, we envision … Read More

Rock Cycle

The rock cycle is the continuous process of the changing states of earth minerals. It describes the formation, breakdown, and reformation of a rock. To understand rock cycle, we must learn about types of rocks first. This course covers types of rocks and the rock cycle. Types of Rocks A rock is made of collection … Read More

Continental Drift Theory

Continental drift theory was developed in 1912 by Alfred Wegener, a German meteorologist, climatologist, and geophysicist.  This course covers Continental drift and Plate tectonic theory. Continental Drift According to Alfred Wegener, the continents had all originally been a part of one enormous landmass or supercontinent about 240 million years ago before breaking apart and drifting … Read More

Human Blood Types

Karl Landsteiner discovered the ABO human blood types in 1901. Until then, blood had been assumed to be the same for everyone, thus leading to many tragic consequences of blood transfusions. ABO blood groups are determined by the gene I (isoagglutinin). There are three types of alleles of gene I, namely, IA, IB and Io. … Read More