1. A mouse brain.
This cross section shows the cerebellum of a mouse. The cerebellum is the brain’s locomotion control center. Every time you tie your shoelaces or throw a ball, thank your cerebellum.
2. Hair cells that sense sound in your ear.
These cells get their name from the hairlike structures that extend from them into the fluid-filled tube of the inner ear. When sound reaches your ear, the hairs bend and the cells convert this movement into signals that are sent to the brain.
Nearly half of our blood is composed of red blood cells. T cells, shown in orange, are an essential part of the immune system and platelets (green) clump together into clots to stop the bleeding when you get injured.
4. A zebrafish embryo.
This zebrafish embryo is just 22-hours-old. In another 14 hours, all of the major organs will have started to form.
5. A mouse’s eye with different cell types highlighted.
Each colour represents a different type of cell in the retina. There are nearly 70 different types in total.
6. Layers of nerve cells in the retina.
This image captures the many layers of nerve cells in the retina. The top layer in green is made up of cells called photoreceptors that convert light into electrical signals to send to the brain.
7. Anthrax bacteria being swallowed by an immune system cell.
Multiple anthrax bacteria, in green, are being enveloped by an immune system cell shown in purple.
8. A cell dividing.
This cell is preparing to divide. Two copies of each chromosome (blue) are lined up next to each other in the center of the cell. Next, protein strands (red) will pull apart these paired chromosomes and drag them to opposite sides of the cell before the cell splits into two daughter cells.
9. Anglerfish ovary.
This is a cross-section of an anglerfish’s ovary. Once matured, these eggs will be released in a gelatinous, floating mass.
10. Ebola virus.
After multiplying inside a host cell, the stringlike Ebola virus is emerging to infect more cells. Ebola is a rare, often fatal disease that occurs mainly in tropical regions of sub-Saharan Africa.
11. Larvae from a parasitic worm.
The parasitic worm that causes a disease called schistosomiasis hatches in water and grows up in a freshwater snail, as shown here.
12. Birth of a yeast cell.
Two yeast cells had sex and this is what happened afterwards. A mother and father cell fuse and create one large cell that contains four offspring. When environmental conditions are favorable, the offspring are released.
13. Pollen grains.
These are the horrible things that make you sneeze and your eyes itch in summer. Pollen grains are the male germ cells of plants, released to fertilize the corresponding female plant parts.
14. A fruit fly ovary.
A fruit fly ovary, shown here, contains as many as 20 eggs. Fruit flies are hugely useful in scientific research because they reproduce so quickly, with as many as three generations in a single month.
This human T cell (in blue) is under attack by HIV (in yellow), the virus that causes AIDS. The virus specifically targets T cells, which play a critical role in the body’s immune response against invaders like bacteria and viruses.
16. Zebrafish fin.
Originally from the waters of India, Nepal and neighboring countries, zebrafish can now be found swimming in science labs throughout the world.
17. Flower-forming plant cells.
The stem cells at the growing tip of this Arabidopsis plant will soon become flowers. Arabidopsis is well studied by biologists because its entire life cycle lasts just six weeks.
18. Developing nerve cells.
These developing mouse nerve cells have a nucleus (yellow) surrounded by a cell body, with long extensions called axons and thin branching structures called dendrites. Electrical signals travel from the axon of one cell to the dendrites of another.
19. Dividing cells.
This pig cell is in the process of dividing. The chromosomes (purple) have already replicated and the duplicates are being pulled apart by fibers of the cell skeleton known as microtubules (green).
20. Gecko lizard toe hairs.
Geckos have around 500,000 toe hairs, each of which is about one-tenth the thickness of a human hair. These hairs split into smaller hairs that fray into spatula-shaped structures, which lets geckos do amazing things like climb up walls.
Despite being primitive, jellyfish have a nervous system (stained green here) and muscles (red).