Trees in the rainforest are so tall because they compete for sunlight. Hope this helps!
Answer:
mtDNA is used, consider forensic laboratories to characterize bone remains and identify individuals who have other evidence
The disadvantage of using mtDNA in relation to nuclear DNA is that it does not identify individuals unambiguously, it only detects relationships between groups of individuals
Consequently plant roots will get more moisture with less effort. It also improves soil structure due to alternate drying and cooling and soil aeration which helps in multiplication of micro-organisms. This is the reason that farmers plough their field during summer.
Hope this helps!
~ Kana ^^