Gene-Seed

In the Warhammer 40,000 universe, Gene-seed is the material that allows for the creation of the superhuman Space Marines. There are 19 types of Gene-Seed, each used to create one of the 19 specialized organs implanted into the body of a human warrior to create a Space Marine.

Secondary Heart
This is the first and least difficult implant to install. The Secondary Heart increases blood supply and pumping capacity,is capable of taking over entirely should the primary heart fail, and enables Marines to survive low-oxygen conditions and traumatic injury.

Ossmudula
This implant uses specially created hormones, combined with a diet high in ceramic-based chemicals, to considerably strengthen the skeleton of a Space Marine. Two years after the implantation, the Marine's skeleton will be exponentially stronger; and the rib cage will be fused into a solid mass of interlaced bone plates.

Biscopea
Implanted into the chest cavity, this small, spherical implant bolsters muscle growth throughout the Marine's body

Haemastamen
Implanted into a main blood vessel, the Haemastamen alters the Marine's blood composition to carry oxygen and nutrients more efficiently. It also acts as a growth control for many of the later implants.

Larraman's Organ
This organ manufactures Larraman Cells. These serve the purpose of platelets, but act faster and more effectively. When a Marine is wounded, Larraman Cells are released, attached to leukocytes. At the site of the injury, they form a skin substitute of near-instant scar tissue, effectively preventing massive blood loss and infection.

Catalepsean Node
Implanted into the back of the brain, this implant allows a marine to function in situations where sleep is impossible to safely attain. Instead, when deprived of sleep, the Catalepsean Node, 'cuts in', allowing the Marine to 'switch off' sections of the brain sequentially, while remaining awake and alert. The longest any Space Marine has ever been on active combat duty without rest is 328.7 hours, achieved by a squad of the Crimson Fists.

Preomnor
The Preomnor is a decontamination chamber inside the chest cavity, effectively a 'pre-stomach'. It chemically analyzes ingested materials and neutralize toxins. The Preomnor enables the Marine to eat normally inedible substances and resist poisons.

Omophagea
Implanted into the spinal cord, this organ is designed to absorb DNA related to experience or memory. This enables the Marine to gain information, in a survival or tactical sense, simply by eating an animal indigenous to an alien world or situation. This organ may also have led to the various flesh-eating or blood drinking rituals performed by some chapters, notably the Blood Angels and their successors.

Multi-lung
The multi-lung is a 'third' lung, able to absorb oxygen from environments poor in oxygen. Breathing is accomplished through a sphincter in the trachea. A similar muscle closes the primary lungs off in toxic environments, while oxygen is absorbed by filtering out the poisonous elements in the multi-lung.

Occulobe
Essentially, this organ allows technicians to enhance a Marine's eyesight, granting him exceptional vision and the ability to see normally in low-light environment.

Lyman's Ear
This implant renders a Marine immune to dizziness and nausea(see Cochlea), and enables a Marine consciously filter out "white noise".

Sus-an Membrane
This implant allows a Marine to enter a catatonic or "suspended animation" state. It can allow a mortally wounded Space Marine to survive his injuries, and bring the metabolism to a standstill. However, specific stimulations from an external source are required to bring a suspended Space Marine back to full life. The longest recorded period of this state was Brother Silas Err of the Dark Angels for 567 years.

Melanochrome
Linked to pigment cells in skin, this allows the Marine's skin to shield him from dangerous levels of radiation.

Oolitic Kidney
This organ works in conjunction with the Preomnor, filtering blood to rapidly remove toxins.

Neuroglottis
This organ allows a Marine to assess a wide variety of things simply by taste. From poisons to chemicals to animals, a Marine can even track its quarry by taste alone.

Mucranoid
Altering sweat glands, this organ secretes an oily substance that coats the skin, protecting it from extreme temperatures and to some extent, vacuum environments.

Betcher's Gland
Implanted into multiple locations inside a Marine's mouth, these glands transforms a Marine's saliva into corrosive, blinding acid, strong enough to work through iron bars. It is generally accepted that the marines have a coating of somekind inside their mouth to prevent their own tissue from being burnt by this acid.

Progenoid Glands
Implanted into both the neck and chest cavity, these serve to collect and cultivate the gene-seed from a Space Marine's body, and to safeguard it for the continuity of a Chapter.

The Black Carapace
The last and possibly most important of all implants, this neuroreactive material is implanted directly under the skin. After a few hours, the material hardens and interlinks with the Marine's own nervous system. Points are then cut into the Carapace which allows a Marine to directly interface with his Power Armor.

Creating Gene-seed Implants
The gene-seed of a chapter is passed down through the Progenoid Glands, (the 18th implant) that collects and stores genetic data. They mature over a period of five to ten years, and can be harvested at any time after reaching maturity, up until a short time after death. Each gland contains the seed for one of each of the specialized organs necessary to create a Space Marine. Thus, a Marine's death means another will be added to the ranks, and the fallen hero lives on in some small way in each new warrior that follows in his footsteps.