What are the two broad categories of fibrous connective tissue based on their relative abundance of fibers?

Collagen and Elastin

Explanation:

Collagen:These are the dominant fibre type in most connective tissues.A principal feature of this fibrous connective tissue is its flexibility combined with great tensile strength.Examples include dermis,tendons,ligaments and organ sheath(such as the sclera,or "white" of the eye.

Elastin:It is a dense connective tissue.It functions to give the connective tissue it's elasticity.Examples include the the wall of the aorta and the elastic ligament of the spine

answer; /// i believe the correct answer is (reactants);

genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).