AQA Biology Unit 1 - Cell Biology Basics Flashcards

Vocabulary-focused flashcards covering cell structure, microscopy, cell division, transport, and practical skills for AQA Biology Unit 1.

Cell

The basic structural and functional unit of living organisms.

Cell membrane

Controls movement of substances into and out of the cell.

Cytoplasm

Where most chemical reactions occur.

Nucleus

Part of the cell that controls activities and contains DNA arranged into chromosomes.

Mitochondria

Site of aerobic respiration which releases energy.

Ribosomes

The site of protein synthesis.

Chloroplasts

Found in plant cells; the site of photosynthesis and contains chlorophyll.

Vacuole

Contains cell sap and maintains pressure inside a plant cell.

Turgor pressure

Pressure created when water pushes against the cell wall.

Plant cell wall

Made of cellulose; provides support and strength to the cell.

Plasmids

Small loops of DNA found in bacterial cells.

Prokaryotes

Cells, such as bacterial cells, that do not contain a nucleus.

Circular DNA loop

The form of genetic material found in the cytoplasm of bacterial cells instead of a nucleus.

Slime capsules

Structures in some bacteria used for protection.

Flagella

Bacterial structures used for movement.

Magnification

How much larger an image is compared to the real object.

Magnification formula

$$\text{Magnification} = \frac{\text{image size}}{\text{real size}}$$

Real size formula

$$\text{Real size} = \frac{\text{image size}}{\text{magnification}}$$

Micrometre (µm)

A unit of measurement where $1000\,\mu\text{m} = 1\,\text{mm}$.

Resolution

The ability to distinguish between two points.

Electron microscope

A microscope with higher resolution because it uses electrons with much shorter wavelengths than light.

Specialised cell

A cell adapted for a specific function.

Acrosome

Part of a sperm cell that releases enzymes to penetrate the egg.

Nerve cell

A cell adapted to transmit electrical impulses via a long axon and branched connections.

Lignin

A substance that strengthens xylem vessels.

Phloem vessels

Vessels that transport dissolved sugars.

Cell cycle

The series of stages leading to cell division.

Mitosis

The stage of the cell cycle where chromosomes are separated into two nuclei, producing two genetically identical daughter cells.

Tumours

Formations caused by cells dividing uncontrollably.

Stem cells

Undifferentiated cells able to become different cell types.

Meristem cells

Important cells in plants that allow continuous growth.

Diffusion

Net movement of particles from high to low concentration.

Osmosis

Movement of water through a partially permeable membrane from dilute to concentrated solution.

Active transport

Movement against a concentration gradient using energy released from respiration.

Reliability

Consistency of results in experiments.

Accuracy

How close results are to the true value.