What does it mean when a molecule is said to be "polar" ?

Embryonic stem cells are cells derived from an embryo. these cells can be used to create new tissues for patients suffering from certain illnesses and disorders. which statement best summarizes why the use of embryonic stem cells could be seen as unethical?

Arrange the following in the correct sequence, from earliest to most recent, in which these plant traits originated. 1. sporophyte dominance, gametophyte independence 2. sporophyte dominance, gametophyte dependence 3. gametophyte dominance, sporophyte dependence a) 1 → 2 → 3 b) 2 → 3 → 1 c) 2 → 1 → 3 d) 3 → 2 → 1 e) 3 → 1 → 2

Which medullary index indicates a human hair? a. 0.653 b. 0.733 c. 0.516 d. 0.256