line of descent vs blood

line of descent and blood both are nouns.

Word	Noun	Adjective	Verb	Adverb
line of descent	Yes	No	No	No
blood	Yes	No	Yes	No

As nouns, line of descent and blood are synonyms defined as:

Other synonyms of line of descent include ancestry, blood line, bloodline, descent, line, lineage, origin, parentage, pedigree, stemma, stock.

line of descent (noun)	blood (noun)
the hereditary derivation of an individual	temperament or disposition
the kinship relation between an individual and the individual's progenitors	the fluid (red in vertebrates) that is pumped through the body by the heart and contains plasma, blood cells, and platelets
	the hereditary derivation of an individual
	people viewed as members of a group
	a dissolute man in fashionable society

line of descent (verb)	blood (verb)
	smear with blood, as in a hunting initiation rite, where the face of a person is smeared with the blood of the kill