How do sieve tube member (stm) cells differ from tracheids? stm cells function as living cells; tracheids function as dead cells
stm cells lack a companion cell; tracheids have a companion cell stm cells occur in angiosperms; tracheids only occur in gymnosperms stm cells have secondary cell walls; tracheids?
Sieve tube member cells are living cells, have companion cells and are typical for gymnosperms. Tracheids have secondary cells walls and are functioning like dead tubes that enable the flow of water through the plant. Tracheid occurs in vascular plants, both angiosperms, and gymnosperms.
<u><em>Nitrous oxide is removed from the atmosphere when it is absorbed by certain types of bacteria or destroyed by ultraviolet radiation or chemical reactions.</em></u>
