Found 122 Articles for Biology Articles

Darwin explained evolution as “descent with modification” whereby organisms evolve and accumulate changes from their ancestors which help them adapt and survive. Since Darwin, there have been many speculations and attempts to understand exactly how the origin of species occurs- has evolution been a result of one species being transformed into another, or is it due to branching off from an ancestral species? Although both events lead to evolution, the difference between them lies in whether they are occur in the same lineage (anagenesis) or split into different lineages (cladogenesis). Moreover, is evolution a result of gradual changes over time ... Read More

A metabolic pathway involves a series of chemical reactions wherein a particular molecule undergoes transformations, resulting in a specific product(s). Each step in a metabolic pathway is catalyzed by enzymes. Metabolic reactions manage the resources of the cell via two kinds of processes, namely the anabolic pathway and the catabolic pathway. The former is a constructive pathway and involves biosynthesis or the building of new molecules. Such reactions require energy input, usually in the form of ATP. The latter on the other hand, is a degradative pathway, leading to the breakdown of substances. These kinds of pathways would require an ... Read More

Living things are classified into five kingdoms including animal, plant, fungi, protista and monera. In kingdom animalia, all members are multicellular organisms, however they do not express the similar organisational pattern. Animals can be categorised into five different groups including mammals, fish, amphibians, birds, and reptiles. They all depend on the environment such as air, food, water, and shelter to survive. Amphibians are the only vertebrates that spend a part of their life in water and a part on land. Therefore, they are different from other groups of animals. Lobe-finned fish evolved into the first amphibian about millions of years ... Read More

Amoebiasis is a form of gastroenteritis i.e., the inflammation of the gastrointestinal tract, and is generally associated with poor sanitation conditions. This disease is caused by an amoebozoa known as Entamoeba histolytica and is the third leading cause of death due to parasitic diseases around the world, following Malaria and Schistosomiasis. It accounts for as many as 100, 000 deaths per year, globally, and more than 500.000 people are infected per year! Entamoeba spp. are infective amoebozoans, known to cause infections in all classes of vertebrates, along with some invertebrates. Although humans are hosts to about six species of Entamoeba, ... Read More

Nutrient cycling is an important process that ensures the harmonious functioning of the ecosystem. Nitrogen is amongst the most crucial nutrients for a living organism and hence, its cycling between the atmosphere and biosphere is essential. The nitrogen in the atmosphere is not bioavailable and is subject to important transformations− biological nitrogen fixation, assimilation, ammonification, nitrification and denitrification, being converted from one chemical form to the other. The process of ammonification is essential in making nitrogen available for growth of plants and animals, and is discussed at length in this article. What is Ammonification? Once nitrogen has been fixed into ... Read More

The man-made barrier that is created across the river or underground streams to limit the flow of water is a dam. By doing this way artificial lakes or artificial reservoirs are created. This then has further uses. Such as irrigation, household uses, flood suppression, industrial use, aquaculture, generation of electricity, etc. Their structure is made with the help of bricks, clays, concrete, cement, Iron rode, etc. Even though it has many advantages but there are some disadvantages too. As dams are constructed across the river, it will affect the ecosystem of the river. Since the river is home to many ... Read More

The human body is equipped with a powerful immune system to protect from harmful substances. The purpose of the immune system is not confined strictly to setting a fight against an invader. It keeps a memory of the invader after a successful recognition. There are some breaches where the immune system attacks unexpected components. When an individual's immune system attacks common substances that are harmless to fellow individuals it is termed an Allergy. Autoimmunity is the condition where an individual's immune system mistakenly attacks the self cells and tissues. What is an Allergy? Allergy is the body's reaction to typical ... Read More

What is the Alimentary Canal? Humans have a complex body plan and hence possess a digestive tube with two openings, a mouth which is the anterior end and an anus which is the posterior end. The food material moves along the alimentary canal in a single direction, passing through a series of specialised organs. Such a tube whose primary function is to facilitate movement of the food particles and ultimately aid in nutrition is referred to as the Alimentary Canal. The human alimentary canal consists of the buccal cavity, the oesophagus, the stomach, the small and large intestine and the ... Read More

Algae are commonly thought of as slimy, green films formed in stagnant waters (freshwater and marine). An Alga (plural− algae) can be microscopic or macroscopic spanning a few feet in length depending on species. Though algae are considered culprits spoiling the beauty of transparent freshwater, they are the main source of atmospheric oxygen supporting many life forms on earth. Algae are a large and diverse group. Understanding them requires tons of knowledge in terms of their characteristics, occurrence, and life cycle. The study of algae is called phycology and people carrying out extensive studies on algae are called phycologists. What ... Read More

Atmosphere is a thin protective blanket of air or gases surrounding the earth. Air is an essential element of nature that supports life on earth. The contamination of the atmosphere by harmful chemicals or biological and physical materials is one of the most serious global problems. This problem is termed as Air pollution. It may be caused by natural or man-made activities. But air pollution is majorly caused by human activity. It is injurious to the health of human beings and other living organisms and damages climate and materials. Now it is very important to acknowledge the cause and ... Read More