ancestry vs blood line

ancestry and blood line both are nouns.

Word	Noun	Adjective	Verb	Adverb
ancestry	Yes	No	No	No
blood line	Yes	No	No	No

As nouns, ancestry and blood line are synonyms defined as:

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

ancestry (noun)	blood line (noun)
inherited properties shared with others of your bloodline	the hereditary derivation of an individual
the hereditary derivation of an individual