This is possible to a degree by using in-game commands made available by enabling cheats. However, this command won't necessarily change a biome's blocks, but an area's biome classification.

In Minecraft, you can place and remove blocks using your bare hands or a designated tool based on the block's type of block.

How to Get a Command Block in Minecraft Despite the fact that you can obtain any blocks in the creative mode, you can’t find the command block in the creative inventory.

Minecraft: Education Edition can now teach kids how to code with the new Code Builder tool and the 'Agent', an in-game robot. Mojang will add Command Blocks in Education Edition later this year.