Which vascular plant group once had tree-sized individuals

What kingdom will you classify this organism
April 18, 2020
Research findings for a particular pathogen
April 18, 2020

Which vascular plant group once had tree-sized individuals

Q1. What are two instances where microorganisms may someday be utilized to synthesize biopolymers most usually associated with products of the petrochemical industry today? Why are these studies important in the long term?

Q2. Which lower vascular plant group once had tree-sized individuals (ca. 250- 300 mya) in swampy areas; their fossilized remains became a significant part of most coal deposits in the US?