7. plant growth increases the length of shoots and roots, while growth results in an increased girth as layers of woody tissue are laid down.

Primary plant growth increases the length of shoots and roots, while secondary growth results in an increased girth as layers of woody tissue are laid down.

Explanation:

Primary growth is as a result of rapid cell division in the shoot apical and root apical meristem. Primary growth leads to an increase in the length of the shoot and the root.

Secondary growth is as a result of cell division in the lateral meristems (vascular cambium and the cork cambium) thereby making the root and stem thick. Secondary growth leads to an increase in thickness or girth of the plant as layers of woody tissue are laid down.

the correct answer is 4) heat and pressure

metamorphic rocks arise from transformation of existing rocks types, in a process called metamorphism. during metamorphism the original rock(prolith) change into metamorphic rock by heating (150-200c) and pressure of more than 1000 bar. the original rock can be sedimentary, igneous, or existing metamorphic rock.