5 major problems that ancestoral plants had to overcome in order to make the transition from water to land?

Question

and 5 solutions to those problems

Answer 1

Getting Water:  Roots and a vascular system

Answer 2

Water is scarce on land so protection from dessication needed. Plants developed a thick waxy cuticle  plus stomata for gas exchange. Reproduction eventually was freed from water dependency by the advent of pollen (reduced male gametophyte or haploid phase)  and the protection of female gametophytes in cones & flower ovaries. The ovary protected seeds (embryo and food stores).

Air is less dense than water so internal support needed. Structural support (cellulose & lignin) also roots as both anchors and a means of extracting water (& soluble nutrients) from soil. This in turn allowed vascular nutrient conduction rather than relying on passive diffusion. This allowed greater size.

Low thermocapacity of air so day night temperatures had a wide temperature range. This kept the early terrestrial plants close to regions with little variation day to night.

High oxygen content and light intensity is higher so plants needed greater protection from damage. New uses of pigments developed.