Step-by-step explanation:
Answer to 1: There are a variety of reasons trees don't grow in this region. First, the permafrost prevents them from taking root, then those that do manage it have shallow root systems that are not an ideal anchor to withstand the high winds. Finally, low precipitation means there is not enough water to support trees.
Answer to 2: The primary factor which determines a biome is the climate. Temperature and precipitation essentially determines what kind of growing season or soil quality the terrain may have, which therefore affects the growth of plants living there.
Answer to 3: Humid
Answer to 4: Wet
Answer to 5: It's either the option dry, the option hot, or both answer choices
Answer to 6: Climate