biological mother vs mummy

biological mother

noun
  • The woman from whom one inherits half of one's DNA and who is the source of one's mitochondrial DNA. 

mummy

noun
  • Any naturally preserved human or animal body. 

  • An embalmed human or animal corpse wrapped in linen bandages for burial, especially as practised by the ancient Egyptians and some Native American tribes. 

  • A reanimated embalmed human corpse, as a stock character in horror films. 

  • A substance used in medicine, prepared from mummified flesh. 

  • mother. 

How often have the words biological mother and mummy occurred in a corpus of books? (source: Google Ngram Viewer )