Mum is a colloquial term for mother, a female parent. The McPherson Unit is the female parent unit. The yolk is synthesised in the liver of the female parent in soluble form. Mommy (or mom) is a term used for a mother, the female parent. Disease resistance is invariably carried by the female parent. Several species of butterfly are known to have female parent sex determination. Once hatched, nestlings are fed by both the male and female parent. Most "Tarebia granifera" are therefore clones of the female parent. A mother is the female parent of a child. A horse's female parent is known as its dam.