Why do few plants grow in the tundra?

In the Arctic tundra, warmth and sunlight are in short supply, even in the summer. ... Only plants with shallow root systems grow in the Arctic tundra because the permafrost prevents plants from sending their roots down past the active layer of soil. The active layer of soil is free from ice for only 50 to 90 days.

Explanation:

The harsh winter climate and lack of sunlight make it hard for plants to grow.

sunlight and warmth is a necessity for plants to grow and make nutrients to survive.

I hope this helps ^^

answer; the tunica intima also called tunica interna, consists of elastic fibers,connective tissue and smooth muscle cells;