Table: lords_breakdown
Columns: affiliation
life_peers
hereditary_peers
lords_spiritual
total

Question: Which Hereditary peers have a Total of 1?
SQL: SELECT "hereditary_peers" FROM lords_breakdown WHERE "total" = 1

Question: Which Total has a Hereditary peer of –, and a Lords spiritual of –, and a Life peers of 2, and an Affiliation of plaid cymru?
SQL: SELECT COUNT("total") FROM lords_breakdown WHERE "hereditary_peers" = '–' AND "lords_spiritual" = '–' AND "life_peers" = '2' AND "affiliation" = 'plaid cymru'