A cell is the smallest structural and functional unit of all living organisms, acting as the fundamental building block that can live on its own, replicate, and power life functions (e.g., in a human body or bacteria). These microscopic, self-contained units typically contain a nucleus, cytoplasm, and a cell membrane.
Cellular respiration
Cellular respiration is the metabolic process in which cells break down glucose and other organic molecules using oxygen to produce energy in the form of ATP (adenosine triphosphate), releasing carbon dioxide and water as waste products.
Diffusion
Diffusion is the net movement of particles (atoms, ions, or molecules) from a region of higher concentration to a region of lower concentration.
DNA
DNA (deoxyribonucleic acid) is the hereditary molecule that carries genetic instructions for the development, functioning, growth, and reproduction of all known organisms. Shaped like a double helix (a twisted ladder), it resides in the nucleus of cells, determining individual traits through a unique code.
Ecosystem
An ecosystem is a community of living organisms (plants, animals, microorganisms) interacting with each other and their non-living environment (sunlight, air, water, soil) in a specific area.
Enzyme
An enzyme is a biological catalyst, usually a protein, that accelerates specific chemical reactions within living cells without being consumed in the process.
Homeostasis
Homeostasis is the body's self-regulating process that maintains a stable, constant internal environment despite changing external conditions.
Molecule
A molecule is a stable, electrically neutral group of two or more atoms held together by chemical bonds (usually covalent).
Nucleus
The nucleus is a membrane-bound organelle in eukaryotic cells that acts as the control center, protecting genetic material (DNA) and regulating growth and metabolism. It contains chromosomes, directs protein synthesis, and is essential for cell reproduction.
Organ
An organ is a specialized structure composed of different tissues that work together to perform specific functions within a multicellular organism, such as the heart, lungs, or liver.
Organism
An organism is any individual living thing, such as a plant, animal, fungus, or microorganism (bacterium/archaeon), that functions as an autonomous unit.
Osmosis
Osmosis is the spontaneous, passive movement of solvent molecules (usually water) through a selectively permeable membrane from a region of higher water potential (lower solute concentration) to a region of lower water potential (higher solute concentration).
pH
pH is a logarithmic scale (typically 0–14) used to specify the acidity or basicity of an aqueous solution.
Photosynthesis
Photosynthesis is the biological process where plants, algae, and some bacteria convert light energy (sunlight) into chemical energy, creating glucose (food) and releasing oxygen.
Tissue
Tissue is a group of similar cells and their extracellular matrix, working together to perform a specific function in animals or plants.