Question

Biology: terms used in Biology

Accepted Answer

The following is a categorized list of common biology terms with concise definitions.

Cell Biology

Cell — The basic structural and functional unit of all living organisms.
Organelle — A specialized structure within a cell (e.g., mitochondrion).
Plasma membrane — Selectively permeable lipid bilayer that surrounds a cell.
Cytoplasm — Gel-like fluid inside the cell that contains organelles.
Nucleus — Organelle that stores DNA and controls cell activities.
Mitochondrion — Organelle that produces ATP by cellular respiration.
Ribosome — Molecular machines that synthesize proteins.
Endoplasmic reticulum (ER) — Network for protein (rough ER) and lipid (smooth ER) synthesis.
Golgi apparatus — Modifies, sorts, and packages proteins and lipids for transport.
Lysosome — Organelle containing enzymes for digestion and recycling.

Genetics & Molecular Biology

DNA (deoxyribonucleic acid) — Molecule that carries genetic instructions.
Gene — Segment of DNA that codes for a protein or functional RNA.
Allele — Alternative form of a gene (e.g., dominant or recessive).
Chromosome — Condensed DNA-protein structure carrying genes.
Genotype — The genetic makeup of an organism.
Phenotype — Observable traits resulting from genotype + environment.
Mutation — A change in DNA sequence; can be neutral, harmful, or beneficial.
Transcription — Process of copying DNA into RNA.
Translation — Process of synthesizing proteins from mRNA.
Mitosis — Cell division producing two genetically identical daughter cells.
Meiosis — Cell division producing gametes with half the chromosome number.

Natural selection — Differential survival and reproduction of organisms due to variation.
Adaptation — Heritable trait that increases an organism’s fitness in an environment.
Speciation — Formation of new species from ancestral populations.
Population — Group of individuals of the same species living in an area.
Community — Interacting populations of different species in a location.
Ecosystem — Community plus its physical (abiotic) environment.
Biodiversity — Variety of life at genetic, species, and ecosystem levels.

Homeostasis — Maintenance of a stable internal environment (e.g., temperature).
Tissue — Group of similar cells performing a common function.
Organ — Structure made of tissues that performs a specific job (e.g., heart).
Organ system — Group of organs working together (e.g., circulatory system).

Enzyme — Protein that speeds up chemical reactions (biological catalyst).
ATP (adenosine triphosphate) — Primary energy currency of the cell.
Photosynthesis — Process by which plants convert light energy into chemical energy.
Cellular respiration — Process of breaking down glucose to make ATP.
Pathogen — Organism that causes disease (e.g., bacterium, virus).
Antibiotic — Drug that kills or inhibits bacteria (not effective against viruses).

Make flashcards (term on one side, concise definition on the other).
Group terms by concept (e.g., all cell organelles together) to build connections.
Use diagrams (cells, pathways, food webs) — visuals help retention.

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