blood line vs ancestry

blood line and ancestry both are nouns.

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

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

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

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