These bumps are called nodules
nodules
"symbiotic"
OK well free nitrogen is fixed by bacteria that live in the soil. some bacteria live in nodules, or bumps , on certain plant roots. the bacteria get food from the plants, and plants absorb fixed nitrogen from the bacteria. animals get nitrogen by eating plants or by eating prey that have eaten plants. fixed nitrogen may enter the soil in other ways too. a small amount of free nitrogen in the air by lighting. it is carried to the ground by rainfall. fixed nitrogen also enters the soil because of decomposers. decomposers break down dead organisms, and fixed nitrogen is released in the soil. the fixed nitrogen can be absorbed by plant roots.
Bumps
Clostridium Tetani
the bumps on the moon are called craters which has happened by comets and other objects.
The red bumps on a turkey's head are called CARUNCLES.
They are called milk glands(bumps) prepares baby's milk
Warts
They are called manarilose
osteoderms
The "bumps" you refer to are called the "lobes". They are a precise size that allows the valves to open and close correctly in an engine.