The immune system is the body’s defense mechanism against harmful invaders such as bacteria, viruses, fungi, and parasites. It consists of a network of cells, tissues, and organs, including white blood cells, the lymphatic system, bone marrow, and the spleen, all working together to protect the body. The immune system is divided into two main par

The human brain is one of the most complex and powerful organs in the body, responsible for controlling thoughts, emotions, memory, decision-making, and all bodily functions. It is composed of approximately 86 billion neurons, which communicate through electrical and chemical signals. The brain is divided into different regions, each specialized fo

 Evolution is the process by which species change over time through variations in traits that are passed down from one generation to the next. These changes occur due to mutations in DNA, which can result in new characteristics. When these traits improve an organism’s ability to survive and reproduce in its environment, they are more likely to b

An ecosystem is a community of living organisms interacting with their physical environment. These interactions form a network of energy flow and nutrient cycling, ensuring the survival of all species within it. Ecosystems can be as small as a pond or as large as a forest, ocean, or the entire planet. They include both biotic (living) components, s