View a gallery of images and videos of over 200 types of cells

A gallery of medical illustrations from NIH

The National Institutes of Health provides educational materials for broad use. The institute hosts a Flickr account with many different image galleries, including this one (with over 70 images to date) that illustrate and annotate curious phenomena, from the life cycles of a malaria parasite to the comparison of male and female bladders. Explore the gallery here.

Explore what each organelle does within various types of cells

In "Cell Anatomy Viewer," users can explore interactive illustrations of animal, plant, fungal, and bacterial cells. Clicking on an organelle, such as a lysosome, the nucleolus, or the Golgi complex, provides descriptions of its characteristics and functions.

The secret lives of cells

Cutting-edge microscopy has revealed previously unseen interactions of biological molecules within their cellular environment, enabling scientists to observe and analyze the molecules in a holistic view. This podcast explains the minute advancements made over the last few decades in observing cells, revealing how scientists have come and what the future holds for the field.

View a collection of images and videos of coral reefs from around the world.

Take a 360-degree look at biochemical activity from within a human cell

In this tour, users can observe the dynamic processes that occur within the basic units of the human body, including the production and transport of proteins and the assembly and disassembly of microtubules—thin, cylindrical structures that provide structural support and a means of moving material within the cell.

What is a cell? A great quick overview.

YourGenome.org furnishes a collection of information on cells and how they work. Every body has trillions of cells, each serving a specific function: making proteins, processing chemicals, and creating energy. Every cell contains a genome, a set of instructions for the cell's function. Brush up on your cells for a better grasp on genetics.

The inner life of a cell

White blood cells are responsible for protecting the human body from infection. This video uses biophysical data from Harvard researchers to accurately demonstrate what goes on inside one white blood cell as it works within the immune system.

View a colorful gallery of solar features, including coronal loops and filamentary prominences, curated by the National Solar Observatory.

View a collection of historical documents about molecular biology's history

The collection features materials related to those involved in the discovery of DNA and provides historical context for the discoveries of RNA, various viruses, and important bioproteins. The items include photographs, business correspondence, manuscripts, and scientific instruments.

Stem cell therapies

Stem cells' special attributes interest researchers developing new therapeutic tools for a variety of health problems. Much of this research is done with support from the National Institutes of Health (NIH). This page offers a snapshot of research programs funded by the NIH and the health problems those programs focus on.

Explore human anatomy with these beautiful images

The Human Organ Atlas offers detailed 3D images of dozens of human organs. It was created with very bright X-rays from a particle accelerator, which is formally called a synchroton imaging method.

Explore a gallery of space-based images and animations of Earth

This collection compiles shots of well-known locations, such as US national parks, and natural features, including aurora borealis and fall foliage, to provide a high-level view of Earth's surface.

View a gallery of bioluminescent organisms, including jellyfish and mushrooms

Some species produce a quick flash of light, while others glow steadily with an eerie glow, often to seek attention or in response to being disturbed. Snails, worms, fungi, and other organisms highlight that this ability evolved independently, rather than from one common ancestor.

Explore over 46,000 pages of Charles Darwin's manuscripts

The American Museum of Natural History hosts almost 35,000 digitized folios related to evolution within the fields of botany and zoology from Darwin's Beagle voyage. High-resolution color images, geological findings, and annotated books from Darwin's personal library are also viewable.

View a gallery of biofluorescent animals, which contain cells that emit various colors when exposed to ultraviolet light.

View a media gallery from the assembly of Voyager 1 and 2

This archive includes the many steps it took to put together each Voyager probe. Photos focus on individual parts, like the 8-track tape deck, the large dish-shaped antenna, and its long arm magnetometer boom.

See rare Civil War photographs preserved by the National Archives

The Civil War was the first major American conflict documented by a camera, with its images distributed widely to the public. The National Archives' digital collection offers thousands of original Civil War images: portraits, battlefields, hospitals, and everyday life.

View a gallery of diatoms—algae surrounded by glass-like shells—captured via microscope.

Explore 3D models of some of the most dangerous viruses, allowing us to understand these and other pathogens in new ways.

Explore the abundance of different types of cells in the human body

Lacking a nucleus and other organelles to maximize space for oxygen-carrying hemoglobin and enhance maneuverability through narrow capillaries, there are about four times as many red blood cells and platelets as all other cell types in the body combined. However, about half of the body's cell biomass consists of skeletal myocytes, or muscle fibers.

View the fluorescently stained internal structures of a tardigrade

The photograph won the Olympus Global Life Science Light Microscopy Americas regional award in 2019. Using chemicals from biofluorescent organisms, the image illuminates internal structures with multiple hues in an otherwise mostly colorless organism.

Explore the National Cancer Institute's archive on cancer treatments, including complementary and alternative medicine.

View a gallery of stunning images taken by the James Webb Space Telescope

While the James Webb telescope collects an astounding amount of scientific data, a major part of its allure is its ability to return stunning, high-resolution images. These images include nearby stars, distant galaxies, and some of the oldest structures in the universe.

All publicly available DNA sequences are available at GenBank

The National Institutes of Health's database stores comprehensive, annotated DNA sequences as part of the International Nucleotide Sequence Database Collaboration. It encourages unrestricted data access within the scientific community while allowing submitters to retain intellectual property rights over their data.

Examine this captivating animation 'building' a human—illustrating the roughly 40 weeks of fetal development.

View galleries of images taken by the Hubble Space Telescope

With more than 1.7 million observations made since 1990, the Hubble Space Telescope has captured images of space missions, planets, stellar nurseries, interstellar comets, star clusters, galaxies, and more. This search tool allows users to sort and filter across these celestial objects to explore over 35 years of Hubble's astrophotography.

More than 100,000 scientific publications between 1953 and 2018 reported using HeLa cells—the cancerous cells nonconsensually taken from a Black woman named Henrietta Lacks in 1951.

'Immortal' HeLa cells—cancerous cells widely used in biomedical research after they were nonconsensually taken from a Black woman named Henrietta Lacks—proliferate easily, causing millions of dollars of damage annually by contaminating lab cell cultures.

View a gallery of photographs of Neptune taken during NASA missions.

Explore the differences between healthy and cancerous cells using a DNA microarray

In this simulation, you will learn how scientists use microarrays to experiment on thousands of genes at the same time. By determining which genes are on or off, users can identify those that contribute to cancer formation.

Some organisms are composed of a single cell visible to the naked eye

By incorporating tough, cellulose-rich cell walls, rapid movement of molecules via cytoplasmic streaming, and other biological techniques, some unicellular organisms can bypass the physical limitations that restrict the size of cells. Organisms such as the Stentor coeruleus and Acetabularia can be seen without microscopes.

60 years after seeing Henrietta Lacks as a patient, her doctor still remembered the unique cervical tumor that gave rise to the 'immortal' cell line now commonly used in biomedical research—it was purple, shiny, and soft—an appearance he said is very different from a typical tumor.

View a sample of the bioluminescent tree of life

This diagram shows 42 different light-producing organisms, from bacteria and fungi to worms, fish, and crustaceans. It illustrates how the ability to produce light has appeared multiple times across the tree of life, rather than stemming from a single ancestor.

Aging is a complex biological process affecting our cells, tissues, and organs.

This interactive website features nearly 40,000 photos from Wikipedia for you to create visual mosaics with.

The human body in 3D

Zygote Body is a free human anatomy tool that allows users to explore the intricacies of the human body in stunning detail. With the click of a mouse, users can isolate by body system or view anatomical structures from any angle. Check out this...

How 3D printing inside cells paves the way for microscopic machines

In 2026, scientists in Slovenia developed a method to 3D print a small elephant, several microscopic geometric objects, and barcodes for cell labeling within living human cells, which continued to grow and divide thereafter. The experiment opens the door to fabricating devices within cells to study and manipulate cellular functions.

Bioluminescent reaction enzymes are often used in biomedical research

Near-infrared luciferase systems allow researchers to image and analyze cellular activity in living animals because they penetrate tissue more deeply than visible light. This provides a means of studying gene expression and protein interactions without harming the animals.

This is what happens inside your body when you're sick

This video details the biology of what happens inside the human body during illness.

Explore a gallery of astronomical images curated by the European Space Agency, which includes illustrations and images of aurorae, planets, stars, galaxies, stellar nurseries, exoplanets, and black holes.

Explore how cells respond to signals from their environment

In "Dropping Signals," users can drag stimuli, such as hormones and light, into various cellular environments to observe cellular responses. These include changing their shape, enabling the transport of chemicals into or out of the cell via the cell membrane, or dividing to compensate for surrounding damaged cells.

View a gallery of plants made to shine using ultraviolet-induced visible fluorescence photography, in which organisms re-emit the ultraviolet light they are exposed to in vibrant, glowing colors.

The National Institute on Drug Abuse's resource library

The National Institute on Drug Abuse website is an in-depth and highly prolific resource on addiction science. Explore the vast scope of this website to access comprehensive guides, data visualizations, and educational materials on all facets of addiction and its treatment.

Cells cannot grow forever due to escalating inefficiency in transporting chemicals

As cells get larger, their volume grows much faster than the surface area through which nutrients and waste products pass, creating a bottleneck that eventually causes cells to die. This forces nearly all organisms visible to the naked eye to comprise enormous numbers of smaller cells, such as the approximately 30 trillion found in the average adult human.

View an illustrative journey of sperm cells navigating toward fertilization

In this series of comic-style panels, a "fellowship" of sperm cells travels through fictionalized versions of reproductive anatomy on their way to an egg cell. Each panel includes informative commentary on each step of the adventure, with research insights provided by a reproductive biologist, a biomedical scientist, and an andrologist.

In 2026, researchers at the University of Minnesota created the world's first synthetic cell—a cell made from non-living chemical components—that can eat, grow, divide, and compete with other cells for resources.

The first line of 'immortal' human cells, which can divide indefinitely and are used in scientific research, was nonconsensually taken from a Black woman.

Pictures of paintings: a virtual art museum

If you can't get to the art museum, maybe try bringing the art museum to you. This independent project presents photographs of select classic, public-domain paintings in an interactive format so you can get the full museum effect from home. Note:...

Explore an interactive 3D model of the brain

The brain contains about 86 billion neurons—nervous system cells—and controls vital bodily functions via electrochemical signals. Neurons form circuits through axons, and different brain regions use these circuits to perform specific tasks.

Henrietta Lacks' tumor cells became the first recognized 'immortal' cell line about 75 years ago, but researchers are still investigating the specific mechanisms that enabled the cells to continuously grow and divide in the laboratory.