CIE/Edexcel Biology – Core Vocabulary

Vocabulary flashcards covering key biological terms from the student’s CIE/Edexcel notes.

Organelle

A component inside a cell that carries out a particular task.

Cell

The basic functional unit of living organisms.

Tissue

A group of cells with similar structures working together to perform a particular function.

Organ

A group of tissues working together to perform a specific function.

System

A group of organs with related functions working together to perform a body function.

Sensitivity

Ability to detect or sense changes in the environment (stimuli) and make responses.

Species

Organisms that can reproduce successfully and produce fertile offspring.

Enzyme

A protein that acts as a biological catalyst, speeding up reactions without being used up.

Catalyst

A substance that speeds up the rate of a reaction without being used up in the process.

Metabolic

Relating to the chemical processes within the body.

Metabolic reaction

A chemical reaction occurring inside living organisms.

Diffusion

Movement of molecules from a region of higher concentration to a region of lower concentration down a concentration gradient.

Absorption

Movement of small food molecules and ions through the intestinal wall into the blood.

Assimilation

Movement of digested food molecules into body cells where they are used and become part of the cells.

Peristalsis

Wave-like contractions of circular and longitudinal muscles of the alimentary canal that move food along.

Sphincter muscle

Special ring-like muscle that can open or close a tube at certain points.

Mucus

Sticky secretion from goblet cells; traps dirt/bacteria in airways and lubricates food in the alimentary canal.

Breathing (Ventilation)

Mechanism that moves air into and out of the lungs, allowing gas exchange.

Respiration

Chemical reaction that releases energy from foods such as glucose.

Transpiration

Loss of water vapour from leaves to the air through the stomata.

Translocation

Movement of sucrose and amino acids in the phloem from sources to sinks.

Potometer

Apparatus designed to measure water uptake in a leafy shoot.

Hormone

A chemical substance produced by an endocrine gland and transported in the bloodstream.

Selective breeding

Human selection of individuals with desirable characteristics and breeding them together.

Variation

Differences between individuals of the same species.

Food chain

Chart showing the flow of energy (food) from one organism to the next, beginning with a producer.

Food web

Network showing the transfer of energy between organisms, beginning with producers.

Trophic level

The position of an organism in a food chain, food web, or ecological pyramid.

Herbivore

An animal that obtains energy by eating plants.

Carnivore

An animal that obtains energy by eating other animals.

Decomposer

Organism that gets energy from dead or waste organic matter (saprotroph).

Habitat

The place where an organism lives.

Population

Group of individuals of the same species living in the same place at the same time.

Bioaccumulation

Build-up of pollutants (e.g., insecticides) in the fatty tissue of an organism.

Community

Populations of different species living together in the same place.

Ecosystem

A unit containing all organisms and their environment, interacting together in a given area.

Biodiversity

Range and variety of living organisms within an ecosystem.

Homozygous

Having identical alleles at a particular locus on both homologous chromosomes (e.g., HH or hh).

Heterozygous

Having different alleles at a particular locus on the homologous chromosomes (e.g., Hh).

Mutation

A rare or random change in DNA.

Mutagen

An agent that causes mutations.

Genome

All the genes present in an organism.

Superovulate

Release of many eggs, often induced for in-vitro procedures.

In vitro

In a test tube or Petri dish outside a living organism.

Stem cell

Unspecialised cell that can divide by mitosis and differentiate into specialised cells.

Inheritance

Transmission of genetic information from generation to generation.

Specialised cell

A cell with specific features enabling it to perform a particular function.

Chromosome

Thread-like structure in the nucleus made of DNA and protein; carries genetic information.

Adaptive feature

Inherited characteristic that helps an organism survive and reproduce in its environment.

Fitness

Probability of an organism surviving and reproducing in its environment.

Sustainable resource

Resource produced as rapidly as it is removed so that it does not run out.

Sewage

Waste matter from human communities, including urine, faeces, and household wastewater.

Sense organ

Group of receptor cells that respond to specific stimuli such as light, sound, touch, temperature, or chemicals.

Antibiotic

Chemical produced by microorganisms that kills bacteria.

Reservoir (Pathogen)

Organism or environment that harbours a pathogen without ill effects, acting as a carrier.

Immune response

Body’s reaction to antigens involving lymphocytes, antibody production, and phagocytosis.

Accommodation (Eye)

Changes in the eye that allow focus on objects at different distances.

Stereoscopic vision

Having two eyes. Each eye forming a slightly different image. The brain combines the information from each eye giving us the stereoscopic vision. This help us to judge the depth and the distance of the object and the speed of the object more accurately.

Recessive allele

Allele expressed in the phenotype only when two copies are present (homozygous recessive).

Codominance

Inheritance pattern where neither allele is dominant; both are expressed in the phenotype.

Sex-linked

Allele located on the X chromosome; more commonly affects males.

Carrier

Heterozygous individual carrying a recessive allele for a condition but not expressing it.

Mutated allele

Allele altered by sudden change during DNA replication, producing a different phenotype.

Transgenic

Relating to DNA transferred from one species to another.

Transgenic organism

Organism that contains gene(s) from a different species.

Polygenic

A characteristic controlled by many genes.

Recombinant

Containing DNA from another species.

Gene

Section of DNA that codes for a particular protein.

Allele

Alternative form of a gene; different versions of the same gene.