AQA Biology GCSE Topic 1: Cell Biology Notes

A compilation of key terms and definitions related to Cell Biology.

Prokaryotic cells

Cells that do not have a nucleus or other membrane-bound organelles, such as bacterial cells.

Eukaryotic cells

Cells that have a nucleus and other membrane-bound organelles, such as animal and plant cells.

Organelle

A specialized structure within a cell that performs a specific function.

Differentiation

The process by which cells become specialized for specific functions.

Mitosis

The process of cell division that results in two identical daughter cells.

Stem cells

Undifferentiated cells that can divide to produce more cells and can differentiate into specialized cell types.

Diffusion

The movement of particles from an area of higher concentration to an area of lower concentration.

Osmosis

The movement of water across a semi-permeable membrane from a dilute solution to a concentrated solution.

Active transport

The movement of particles against their concentration gradient, requiring energy.

Chloroplasts

Organelles in plant cells where photosynthesis takes place.

Mitochondria

Organelles where aerobic respiration occurs, providing energy for the cell.

Cytoplasm

The liquid substance inside a cell where chemical reactions occur and organelles are found.

Cell wall

A rigid outer layer found in plant and bacterial cells providing structure and support.

Cell membrane

The semi-permeable membrane surrounding the cell, controlling what enters and leaves.

Nucleus

The organelle that contains DNA and controls the cell's activities.

Bacterial plasmids

Small circular strands of DNA found in bacterial cells.

Xylem cells

Specialized cells in plants that transport water and minerals from roots to shoots.

Phloem cells

Specialized cells in plants that transport the products of photosynthesis throughout the plant.

Zone of inhibition

The area around an antibiotic disc where bacteria cannot grow, indicating the effectiveness of the antibiotic.

Culture medium

A nutrient-rich solution used to grow microorganisms in a laboratory.

Magnification

The process of enlarging the appearance of an object using a microscope.