AQA GCSE Biology - Cell Biology (4.1–4.3) - Key Vocabulary

Vocabulary-style flashcards covering cell structure, cell division, and transport in cells as described in the GCSE Biology cell biology content.

Eukaryotes

Cells with a true nucleus and membrane-bound organelles; include plant and animal cells.

Prokaryotes

Cells that lack a nucleus; have a single circular DNA loop (and plasmids) and are typically bacteria.

Nucleus

Organelle that contains genetic material (DNA) and controls cell activities.

Cytoplasm

Jelly-like interior of the cell where many metabolic reactions occur; contains cytosol.

Cell membrane

Phospholipid bilayer surrounding the cell that controls what enters and leaves.

Mitochondria

Organelle where respiration occurs to release energy (ATP) for the cell.

Ribosomes

Small particles where protein synthesis takes place.

Chloroplasts

Plant/algal organelles where photosynthesis occurs; contain chlorophyll.

Permanent vacuole

Large, central vacuole in plant cells filled with cell sap; helps maintain turgor.

Cell wall

Rigid layer of cellulose in plant cells that provides structural support.

Plasmids

Small circular DNA molecules in bacteria that carry extra genes.

Sub-cellular structures

Components inside cells (e.g., nucleus, membranes, mitochondria, ribosomes).

Cell differentiation

Process by which cells become specialised in form and function.

Stem cells

Undifferentiated cells capable of giving rise to multiple cell types; sources include embryos, adult bone marrow, and plant meristems.

Meristem

Plant tissue containing undifferentiated cells that can differentiate into various plant cells.

Electron microscope

Microscope with high magnification and resolving power, revealing fine sub-cellular detail.

Magnification

Ratio of image size to real size (magnification = image size ÷ real size).

Real size

The actual size of an object being viewed.

Image size

The size of the object as it appears in an image or on a photograph.

Light microscope

Optical microscope with lower magnification/resolution than an electron microscope; used to observe cells.

Culturing microorganisms

Growing microbes in nutrient media under aseptic conditions.

Binary fission

Amoeba-like division by which bacteria reproduce to form two identical cells.

Agar plate

Nutrient gel surface used to culture microorganisms and observe colonies.

Zones of inhibition

Clear areas around antibiotics/antiseptics on an agar plate where bacteria have not grown.

Diffusion

Movement of particles from high to low concentration; can occur across membranes.

Osmosis

Diffusion of water across a partially permeable membrane from dilute to concentrated solution.

Active transport

Movement of substances against a concentration gradient using energy (from respiration).

Exchange surfaces

Surfaces with features like large surface area, thin membranes, good blood supply, and ventilation to enable efficient material exchange.

Surface area to volume ratio

Key factor in exchange efficiency; larger SA:V improves the rate of exchange in organisms.

Tissue

Group of similar cells that work together to perform a specific function.

Organ

Structure made of tissues that performs a particular function in an organism.

Chromosomes

DNA molecules located in the nucleus; carry a large number of genes; normally paired in body cells.

Mitosis

Nuclear division that produces two identical nuclei and new cells.

Cell cycle

Series of stages: growth, DNA replication, mitosis, cytokinesis.

DNA replication

Process by which DNA is copied prior to cell division.