• Biology is the scientific study of life and living organisms, including their structure, function, growth, evolution, and distribution.
  • All living organisms are composed of cells, which are the basic units of life. Cells can be either single-celled (unicellular) or multicellular, and they exhibit various specialized structures and functions.
  • The theory of evolution by natural selection, proposed by Charles Darwin, is a fundamental concept in biology. It explains how species change and adapt over time through the accumulation of genetic variations that provide a survival advantage.
  • DNA (deoxyribonucleic acid) is the hereditary material that contains the genetic instructions for the development, functioning, and reproduction of all known living organisms. It consists of a unique sequence of nucleotides and carries the genetic code.
  • The cell theory states that all living organisms are composed of one or more cells, and cells are the basic structural and functional units of life. This theory was developed by Matthias Schleiden and Theodor Schwann in the 19th century.
  • Organisms are classified into a hierarchical system of taxa based on their shared characteristics. The main levels of classification are domain, kingdom, phylum, class, order, family, genus, and species.
  • Photosynthesis is a vital biological process carried out by plants, algae, and some bacteria. It converts sunlight, carbon dioxide, and water into glucose (a form of stored energy) and releases oxygen as a byproduct.
  • The nervous system is responsible for processing information and coordinating responses in animals. It consists of specialized cells called neurons that transmit electrical signals, enabling communication and control within the body.

  • The immune system defends the body against harmful pathogens such as bacteria, viruses, and parasites. It comprises a complex network of cells, tissues, and organs that work together to recognize and eliminate foreign invaders.
  • Genetics is the branch of biology that focuses on the study of heredity and variation in living organisms. It explores how traits are inherited from one generation to the next and how genetic information is expressed and regulated.
  • Homeostasis is the ability of an organism to maintain stable internal conditions despite changes in the external environment. It is essential for the proper functioning of cells and the overall well-being of an organism.
  • Ecosystems are dynamic communities of organisms interacting with their physical environment. They involve the flow of energy and cycling of nutrients between living organisms and their surroundings.
  • Biotechnology applies biological knowledge and techniques to develop practical applications in various fields, such as medicine, agriculture, and industry. Examples include genetic engineering, the production of biofuels, and the development of new drugs.
  • Evolutionary biology investigates the processes and patterns of evolution, including speciation, adaptation, and the origin of new species. It combines evidence from fossils, genetics, comparative anatomy, and other sources.
  • Ecology is the study of the relationships between organisms and their environment. It examines topics such as population dynamics, community interactions, ecosystems, and the impact of human activities on the natural world.