Minecraft wiki entry for Tick, associated text: Crops may grow or uproot.
Mushrooms may spread or uproot.
Vines may spread.
Fire may burn out or spread.
Ice and snow layers may melt.
Leaves may decay.
Farmland hydration is updated.
Cacti, sugar cane, kelp, bamboo, chorus flowers and sweet berry bushes may grow.
Grass blocks and mycelium may spread.
Grass blocks, mycelium, and nylium may decay (if and only if the condition is met).
Saplings may grow into a tree.
Lava may set fires nearby.
Lit redstone ore turns off.
Nether portal blocks may spawn a zombified piglin.
Turtle eggs crack or hatch.
Campfire smoke appears.
Budding amethyst may grow an amethyst bud on any of its sides as longs as there is no solid block.
Copper blocks (or any of its non-oxidized variants) may advance one stage in oxidation.
Pointed dripstone may fill a cauldron below.