IB Biology Ultimate Guide (copy)

Cell Biology

The study of the structure and function of the cell, the basic unit of life.

Cell Theory

States that all living organisms are composed of cells, cells are the smallest units of life, and all cells come from pre-existing cells.

Prokaryotic Cells

Cells that lack a nucleus and membrane-bound organelles, typically found in bacteria.

Eukaryotic Cells

Cells that contain a nucleus and various organelles, including plant and animal cells.

Plasma Membrane

A phospholipid bilayer that controls the movement of substances in and out of the cell.

Mitosis

A type of nuclear division used for growth, repair, and asexual reproduction, consisting of four stages: prophase, metaphase, anaphase, and telophase.

Cyclins

Proteins that regulate the progression of cells through the cell cycle.

Endosymbiotic Theory

Explains the origin of eukaryotic cells as a symbiotic relationship between primitive eukaryotic and prokaryotic cells.

Stem Cells

Undifferentiated cells with the potential to become various specialized cell types.

Microscopy

The use of microscopes to visualize cells and their components.

Water

The universal solvent, essential for life due to its properties like cohesion and adhesion.

Macromolecules

Large biological molecules, including carbohydrates, lipids, proteins, and nucleic acids.

Enzymes

Biological catalysts that speed up chemical reactions by lowering activation energy.

Nucleic Acids

Biomolecules that store and transmit genetic information; includes DNA and RNA.

DNA Replication

The semi-conservative process by which a cell copies its DNA before cell division.

Transcription

The process of copying a segment of DNA into messenger RNA (mRNA).

Translation

The process of synthesizing proteins from mRNA at the ribosome.

Genetic Code

The set of rules by which information encoded in genetic material is translated into proteins.

Gene Expression

The process by which information from a gene is used to synthesize a functional product, typically a protein.

Biotechnology

The manipulation of living organisms or their components to develop products and processes.

PCR

Polymerase chain reaction, a technique used to amplify specific DNA sequences.

Genetic Engineering

The direct manipulation of an organism's genome using biotechnology.

Mutations

Changes in the DNA sequence that can affect genetic information.

Natural Selection

The process by which organisms with advantageous traits are more likely to survive and reproduce.

Speciation

The process by which new species arise, often through mechanisms like geographic isolation.

Fossil Record

The historical documentation of past life forms through fossilized remains.

Comparative Anatomy

The study of similarities and differences in the structures of different species.

Homeostasis

The maintenance of a stable internal environment in an organism.

Nervous System

The system that transmits electrical signals throughout the body to coordinate responses.

Endocrine System

The system of glands that secrete hormones to regulate physiological processes.

Reflexes

Automatic rapid responses to stimuli, mediated by the spinal cord.

Circulatory System

The system responsible for transporting nutrients, gases, hormones, and waste products throughout the body.

Respiratory System

The system that enables gas exchange between an organism and its environment.

Excretory System

The system responsible for removing metabolic waste products from the body.

Gene Cloning

A technique used to create multiple copies of a specific gene.

Transgenic Organisms

Organisms that contain a gene or genes which have been artificially inserted instead of the organisms acquiring them through reproduction.

Ecosystem

A community of living organisms interacting with their physical environment.

Biodiversity

The variety of life forms within a given ecosystem, region, or on the entire planet.

Conservation Biology

The scientific study of the preservation and protection of biodiversity.

Gene Flow

The transfer of genetic variation from one population to another.

Ecological Succession

The process by which ecosystems change and develop over time following a disturbance.

Population Ecology

The study of how populations grow, interact, and change over time.

Community Ecology

The study of interactions among species within a community.

Carbon Cycle

The process by which carbon is exchanged among the biosphere, geosphere, hydrosphere, and atmosphere.

Nitrogen Cycle

The series of processes by which nitrogen and its compounds are interconverted in the environment and in living organisms.

Primary Succession

The development of plant and animal life in an area without topsoil.

Secondary Succession

The process of regrowth and reestablishment of an ecosystem after a disturbance that does not remove the soil.

Genetics

The study of heredity and the variation of inherited characteristics.

Genetic Disorders

Diseases or conditions caused by mutations or alterations in genes.

Human Genome Project

An international research initiative to map all the genes of the human genome.

Alleles

Different versions of a gene that may result in different traits.

Phenotype

The observable physical or biochemical characteristics of an organism, as determined by both genetic makeup and environmental influences.