# Free science diagrams to download

> Free labelled and unlabelled biology diagrams with printable worksheets and answer keys: plant cell, animal cell, cell membrane, mitochondria, mitosis…

URL: https://www.labcanvas.com/diagrams

Labelled and unlabelled biology diagrams with printable worksheets and answer keys: plant cell, animal cell, cell membrane, mitochondria, mitosis, meiosis, cell cycle, ear, digestive system, heart, human eye, neuron, microscope, water cycle, photosynthesis, dna structure, bacterial cell, virus. Download SVG, PNG or PDF free under CC BY 4.0, or open any diagram in LabCanvas to edit the colours and labels.

Last updated 26 October 2026

[![Labelled plant cell diagram: a box-shaped cell showing the cell wall with plasmodesmata, cell (plasma) membrane, cytoplasm, nucleus with nucleolus and nuclear envelope, rough ER, smooth ER, Golgi apparatus, ribosomes, mitochondrion, peroxisome, chloroplasts with grana, and a large central vacuole bounded by the tonoplast.](https://www.labcanvas.com/diagram-files/plant-cell-diagram/plant-cell-diagram.webp) Plant cell diagram](https://www.labcanvas.com/diagrams/plant-cell-diagram)

[![Labelled animal cell diagram: a rounded cell showing the plasma membrane, cytoplasm, nucleus with nucleolus and a nuclear envelope with pores, rough ER, smooth ER, Golgi apparatus, vesicles, mitochondria, lysosome, peroxisome, centrosome with two centrioles, cytoskeleton fibres and ribosomes.](https://www.labcanvas.com/diagram-files/animal-cell-diagram/animal-cell-diagram.webp) Animal cell diagram](https://www.labcanvas.com/diagrams/animal-cell-diagram)

[![Labeled diagram of a section of cell membrane (fluid mosaic model) with extracellular fluid above and cytoplasm below. Labels: extracellular fluid, carbohydrate chain, glycoprotein, glycolipid, channel protein, cholesterol, peripheral protein, integral protein, cytoskeleton filaments, cytoplasm, hydrophobic tails, phospholipid bilayer and hydrophilic head.](https://www.labcanvas.com/diagram-files/cell-membrane-diagram/cell-membrane-diagram.webp) Cell membrane diagram](https://www.labcanvas.com/diagrams/cell-membrane-diagram)

[![Labeled diagram of a mitochondrion in longitudinal section. Labels: outer membrane, intermembrane space, inner membrane, cristae, ATP synthase, matrix, mitochondrial DNA and ribosomes.](https://www.labcanvas.com/diagram-files/mitochondria-diagram/mitochondria-diagram.webp) Mitochondria diagram](https://www.labcanvas.com/diagrams/mitochondria-diagram)

[![Labeled diagram of mitosis in an animal cell with two homologous chromosome pairs (maternal red, paternal blue). Seven cells show interphase (chromatin, nucleolus), prophase (chromosome, centrosome), prometaphase (spindle fibres, nuclear envelope fragments), metaphase (metaphase plate), anaphase, telophase (nuclear envelope, cleavage furrow) and cytokinesis (daughter cells), with an enlarged chromosome showing sister chromatids and the centromere.](https://www.labcanvas.com/diagram-files/mitosis-diagram/mitosis-diagram.webp) Mitosis diagram](https://www.labcanvas.com/diagrams/mitosis-diagram)

[![Labeled diagram of meiosis with two homologous chromosome pairs (maternal red, paternal blue). Meiosis I: prophase I (tetrad, crossing over, nuclear envelope), metaphase I (homologous chromosomes on the metaphase plate), anaphase I (spindle fibres, centrosome) and telophase I (cleavage furrow). Meiosis II: prophase II, metaphase II (sister chromatids), anaphase II and telophase II, ending in four haploid daughter cells with swapped chromosome segments.](https://www.labcanvas.com/diagram-files/meiosis-diagram/meiosis-diagram.webp) Meiosis diagram](https://www.labcanvas.com/diagrams/meiosis-diagram)

[![Labelled cell cycle diagram drawn as a wheel: interphase with G1 phase, S phase and G2 phase takes most of the circle, and the M phase with mitosis and cytokinesis a smaller arc, with arrows showing the direction. G0 phase branches off G1. Stop signs mark the G1/S checkpoint, G2/M checkpoint and spindle checkpoint. Small sketches show a cell growing, DNA replicating, a cell preparing to divide, chromosomes lined up on the spindle and the cytoplasm dividing.](https://www.labcanvas.com/diagram-files/cell-cycle-diagram/cell-cycle-diagram.webp) Cell cycle diagram](https://www.labcanvas.com/diagrams/cell-cycle-diagram)

[![Labelled diagram of the human ear in section, divided into outer ear, middle ear and inner ear. Labels: pinna (auricle), external auditory canal, tympanic membrane (eardrum), malleus, incus, stapes, middle ear cavity, Eustachian tube, oval window, round window, semicircular canals, vestibule, cochlea and vestibulocochlear nerve.](https://www.labcanvas.com/diagram-files/ear-diagram/ear-diagram.webp) Ear diagram](https://www.labcanvas.com/diagrams/ear-diagram)

[![Labelled diagram of the human digestive system seen from the front, with the head in side view: mouth, tongue, salivary glands, pharynx, oesophagus, liver, gallbladder, stomach, pancreas, duodenum, small intestine, large intestine (colon), cecum, appendix, rectum and anus.](https://www.labcanvas.com/diagram-files/digestive-system-diagram/digestive-system-diagram.webp) Digestive system diagram](https://www.labcanvas.com/diagrams/digestive-system-diagram)

[![Labelled diagram of a human heart in frontal section, seen from the front: superior and inferior vena cava, right atrium, tricuspid valve, right ventricle, chordae tendineae, papillary muscle, pulmonary valve, pulmonary artery, pulmonary veins, left atrium, mitral (bicuspid) valve, left ventricle, interventricular septum, aortic valve and aorta, with blue arrows for deoxygenated blood and red arrows for oxygenated blood.](https://www.labcanvas.com/diagram-files/heart-diagram/heart-diagram.webp) Heart diagram](https://www.labcanvas.com/diagrams/heart-diagram)

[![Labelled diagram of the human eye in side section: eyelids lined by the conjunctiva, cornea, anterior chamber filled with aqueous humour, pupil, iris, lens held by suspensory ligaments from the ciliary body, sclera, choroid, retina with the fovea (macula), optic disc (blind spot), optic nerve and the vitreous humour filling the inside of the eyeball.](https://www.labcanvas.com/diagram-files/eye-diagram/eye-diagram.webp) Human eye diagram](https://www.labcanvas.com/diagrams/eye-diagram)

[![Labelled diagram of a multipolar motor neuron: branched dendrites around the cell body (soma) with its nucleus, the axon hillock, an axon wrapped in a myelin sheath made by Schwann cells with gaps called nodes of Ranvier, and branched axon terminals ending in synaptic knobs, with an arrow showing the direction of the nerve impulse.](https://www.labcanvas.com/diagram-files/neuron-diagram/neuron-diagram.webp) Neuron diagram](https://www.labcanvas.com/diagrams/neuron-diagram)

[![Labelled diagram of a compound light microscope in side view: eyepiece (ocular lens), body tube, arm, coarse focus knob, fine focus knob, base, revolving nosepiece, objective lenses (4x, 10x and 40x), stage clips holding a slide, stage, condenser, iris diaphragm and illuminator, with the light path shown running up through the specimen.](https://www.labcanvas.com/diagram-files/microscope-diagram/microscope-diagram.webp) Microscope diagram](https://www.labcanvas.com/diagrams/microscope-diagram)

[![Labelled water cycle diagram: the sun heats the ocean and water vapour rises by evaporation; transpiration rises from trees and sublimation from a snow-capped mountain; condensation forms clouds that the wind carries inland; precipitation falls on the mountains; surface runoff flows to the sea, infiltration soaks down to the water table, groundwater flow returns to the ocean, and collection happens in the ocean.](https://www.labcanvas.com/diagram-files/water-cycle-diagram/water-cycle-diagram.webp) Water cycle diagram](https://www.labcanvas.com/diagrams/water-cycle-diagram)

[![Labelled photosynthesis diagram: a chloroplast in cross-section showing the outer membrane, inner membrane, stroma, grana of thylakoids with their lumen, stroma lamellae, chloroplast DNA and ribosomes. Light and water enter the light-dependent reactions on the thylakoids, which release oxygen and pass ATP and NADPH to the Calvin cycle in the stroma; the Calvin cycle takes in carbon dioxide, gives out sugar and returns ADP + Pi and NADP+. The overall equation 6CO2 + 6H2O to C6H12O6 + 6O2 is shown in the corner.](https://www.labcanvas.com/diagram-files/photosynthesis-diagram/photosynthesis-diagram.webp) Photosynthesis diagram](https://www.labcanvas.com/diagrams/photosynthesis-diagram)

[![Labelled DNA structure diagram: on the left a right-handed double helix with its sugar-phosphate backbones, base pairs, a nitrogenous base and the major and minor grooves; on the right a flattened ladder section showing phosphates, deoxyribose sugars, the bases adenine, thymine, guanine and cytosine paired A-T and G-C, the hydrogen bonds between them (two for A-T, three for G-C), and the 5' and 3' ends of the antiparallel strands.](https://www.labcanvas.com/diagram-files/dna-structure-diagram/dna-structure-diagram.webp) DNA structure diagram](https://www.labcanvas.com/diagrams/dna-structure-diagram)

[![Labelled bacterial cell diagram: a rod-shaped bacterium showing the capsule, cell wall, plasma membrane, cytoplasm, nucleoid (DNA), plasmids, 70S ribosomes, an inclusion body, many short fimbriae, a long pilus and a flagellum anchored in the cell envelope.](https://www.labcanvas.com/diagram-files/bacterial-cell-diagram/bacterial-cell-diagram.webp) Bacterial cell diagram](https://www.labcanvas.com/diagrams/bacterial-cell-diagram)

[![Labelled virus diagram in two panels. Left: cross-section of an enveloped virus showing spike glycoproteins, the lipid envelope, a layer of matrix protein, a capsid made of capsomeres and the RNA genome. Right: a bacteriophage showing the head (capsid) containing phage DNA, the tail sheath, the base plate and the tail fibres.](https://www.labcanvas.com/diagram-files/virus-diagram/virus-diagram.webp) Virus diagram](https://www.labcanvas.com/diagrams/virus-diagram)

## What each diagram page includes

Every diagram has its own page, and every page is built the same way, so once you know one you know them all. At the top is the diagram in three versions you can switch between: **labelled**, with every part named; **unlabelled**, the same drawing with the labels removed; and a **worksheet**, with numbered blanks in place of the labels. Below it are the downloads: the labelled and unlabelled diagrams as SVG (vector, sharp at any size) and as 3200-pixel PNG with a transparent background, the worksheet as PNG, and a printable A4 PDF with the worksheet and its answer key.

Under the downloads, a table lists every labelled part with a one-line description of what it is or does, numbered in the same order as the blanks on the worksheet, so the table doubles as the answer key on screen. Each page then explains how to label the diagram step by step, compares it with a related structure or process in a table (plant against animal cells, mitosis against meiosis, and so on), adds extra explanation where it helps, and ends with a five-question quiz with the answers explained, frequently asked questions and the textbook sources for every fact.

## Diagrams by topic

- **Cells and their parts:** [animal cell](https://www.labcanvas.com/diagrams/animal-cell-diagram), [plant cell](https://www.labcanvas.com/diagrams/plant-cell-diagram), [bacterial cell](https://www.labcanvas.com/diagrams/bacterial-cell-diagram), [cell membrane](https://www.labcanvas.com/diagrams/cell-membrane-diagram), [mitochondria](https://www.labcanvas.com/diagrams/mitochondria-diagram), [virus](https://www.labcanvas.com/diagrams/virus-diagram).
- **Cell division and DNA:** [cell cycle](https://www.labcanvas.com/diagrams/cell-cycle-diagram), [mitosis](https://www.labcanvas.com/diagrams/mitosis-diagram), [meiosis](https://www.labcanvas.com/diagrams/meiosis-diagram), [dna structure](https://www.labcanvas.com/diagrams/dna-structure-diagram).
- **The human body:** [heart](https://www.labcanvas.com/diagrams/heart-diagram), [human eye](https://www.labcanvas.com/diagrams/eye-diagram), [ear](https://www.labcanvas.com/diagrams/ear-diagram), [neuron](https://www.labcanvas.com/diagrams/neuron-diagram), [digestive system](https://www.labcanvas.com/diagrams/digestive-system-diagram).
- **Processes and the lab:** [photosynthesis](https://www.labcanvas.com/diagrams/photosynthesis-diagram), [water cycle](https://www.labcanvas.com/diagrams/water-cycle-diagram), [microscope](https://www.labcanvas.com/diagrams/microscope-diagram).

All of them are also listed with pictures in the [Education](https://www.labcanvas.com/blog/education) section of the blog. For research figures rather than teaching diagrams, see the [figure templates](https://www.labcanvas.com/templates), which are drawn for papers and cite the studies they follow.

## Using the diagrams in class and for revision

For teaching, project the labelled diagram while you explain each part, then show the unlabelled version and ask the class to name the parts. The A4 worksheet PDF has the numbered diagram with lines to write on, and its answer key on the second page, so it works as homework, a starter activity or a quick test. For revision, cover the parts table, label the worksheet from memory and then check it against the table, and use the quiz at the end of the page to test the ideas behind the labels, not only the names. The SVG and PNG files drop straight into slides, handouts, posters and learning platforms; the transparent PNG sits cleanly on coloured backgrounds.

## Editing a diagram

Every diagram opens in the LabCanvas figure editor in your browser: click **Edit it in LabCanvas** on its page. It opens as separate shapes and text rather than a flat picture, so you can recolour parts to match your slides, translate or simplify the labels, remove parts your course does not cover, add arrows and notes, or combine two diagrams into one figure. You can then export the result as SVG, PNG or PDF at the size you need.

## How to credit or cite a diagram

The diagrams are free under the Creative Commons Attribution 4.0 licence (CC BY 4.0): you may copy, adapt and share them, including commercially and in publications, as long as you give credit. Each page shows a ready-made credit line to copy, in the form “Heart diagram by LabCanvas (labcanvas.com), CC BY 4.0”. Put it in the figure caption, on the slide or in the image credits. If you changed the diagram, say so, for example “adapted from”. In a thesis or report, cite the diagram page’s web address and the date you downloaded it, as you would any other online figure.

## How the diagrams are checked

The labels and descriptions follow open, peer-reviewed introductory textbooks, mostly OpenStax Biology 2e and Anatomy and Physiology 2e, and each page lists the chapters it used. The drawings are simplified teaching illustrations: they show the parts a school or first-year university course expects, in a clear arrangement, and they are not drawn to scale.

## Questions about the diagrams

### Are the diagrams free to use?

Yes. Every diagram is free to download and use, including in homework, teaching materials, slides, posters, websites and publications, under the Creative Commons Attribution 4.0 licence (CC BY 4.0). Credit “LabCanvas (labcanvas.com)”.

### Which formats can I download?

Each diagram comes as SVG (vector), as a 3200-pixel PNG with a transparent background, labelled and unlabelled, and as a printable A4 worksheet with numbered blanks and an answer key (PDF).

### Can I change the labels or colours?

Yes. Click “Edit it in LabCanvas” on a diagram page: it opens in the LabCanvas figure editor as separate shapes and text you can recolour, move and relabel.

### Are the diagrams accurate?

They follow the OpenStax Biology 2e and Anatomy and Physiology 2e textbooks, which each page cites. They are simplified teaching illustrations, not drawn to scale.