__Lily Pollen Grains__This enhanced light micrograph shows orange pollen grains within the stamen of a lily plant. All plants can sexually reproduce, and the process is called alternation of generations (which sounds like slang for a 1970s drug trip). When lilies get it on, the male pollen gametes find their way to the female ovule gametes hidden within the center of the flower in a long stalk called the carpel.

__Algae Colonies__Each green sphere is a colony of Volvox algae with more than 50,000 cells. Scientists study these glowing, freshwater organisms as models for how living creatures develop specialized cells and tissue. Strands of cytoplasm connect neighboring cells, allowing them to communicate, and slender flagella propel the colony through the water.

__Tip of a Corn Root__This above light micrograph shows a cross section of a corn root tip with the nuclei stained blue. Corn root tips are active sites of cell division. Before splitting in half, a cell has to wait until it has enough of everything—proteins, RNA, organelles—for two daughter cells.

__Marsh Plant Root__This psychedelic cluster shows the cross section of cells in the underground stem of a sweet flag plant. If you’ve been to wetlands, you’ve probably seen it with its thick grass-like stems and thin brown spikes. The plant roots grow sideways and sprout up new plants in a rhizome system. The micrograph shows the vascular bundle of cells that transport water and nutrients through the stems.

__Fava Bean Stem Cells__Plant stem cells chill in the tips of roots and shoots, active sites of cell division. In the above micrograph, you can see the nuclei stained dark blue—some caught in mid-mitosis.

__Cotton Bud__This micrograph shows a cross section of the floral bud of a cotton plant. You can see the petals curled around the outer circle, and the reproductive plant organs—stamens and style—radiating out from the center.

__Amphioxus Gills__These are the gills of an aquatic creature called the amphioxus, or if you’d like the more scientific name, Branchiostoma lanceolatum. This tiny invertebrate, usually no more than an inch long, spends most of its life buried in the sand with only its head peeking out to filter feed. But it does have a claim to fame. As the earliest classified Chordate, the amphioxus is a model for studying the evolution of vertebrates. You’re related to that little guy.

__Human Skin Cells__You’re looking at a cross section of human skin. The two dark pink layers at the top make up the epidermis, the tentacles reaching into the light pink dermis. The epidermis, or outer layer of skin, has four types of cells: keratinocytes give your skin strength, flexibility and waterproofing by producing keratin; melanocytes give your skin color by producing melanin; Merkel’s cells are thought to give you touch reception; and Langerhans’ cells are the first line of immune resistance, identifying foreign bodies on your skin.

__Human Embryonic Stem Cells__The blue blobs above are human embryonic stem cells living in culture. Scientists can reprogram your body cells to return to their embryonic state and start self-propagating. Clinical trials for this method started in 2014.

__Prostate Cancer Cells__In this micrograph, prostate cancer cells are living in culture. Normal cells have certain signs that let them know when to stop dividing. Telomeres, for example, hang out on the end of chromosomes. After each division, a bit of the telomeres disappears. Once they’re gone, the cell stops dividing or dies. Both embryonic stem cells and cancer cells express enzymes that repair telomeres, which means they can divide and proliferate unchecked. These are sometimes called immortal cells.

__Ebola Virus__In this epic scanning electron micrograph, red Ebola virions crawl out from a monkey’s kidney cell. Like cells, viruses have RNA or DNA nucleic acids that code for protein genes, but they don’t have the materials to build those proteins. They rely on the living cells to do that for them.

__Bone Cells__The most common cells in mature bones are osteocytes, which are the dark shapes in the above micrograph. Your bones are constantly remodeling in response to the stresses on your body. To build new bone, osteoblast cells lay down collagen fibers that mineralize into an osteoid. Sometimes, osteoblasts can’t get away fast enough and they are trapped within the mineralized osteoids—those are osteocytes.

__Striated Muscle Fibers__You have two types of common muscle cells: smooth and striated. Smooth muscles are responsible for involuntary and unconscious actions like passing food through the digestive system and controlling the size of the iris. Pictured above is a striated skeletal muscle, which denotes the fine parallel line patterns. These do voluntary things like moving your arms akimbo.