can you add another word that fits each group of words?

Question

1. pupa,larva
2. stamin,anther
3.Celsius,Richter
4.bald eagle,cougar

Answer 1

1. egg or adult
2. Filament
3. Fujita or Fujita-Pearson
4. I don't know what group this would be, too many options. I'll for for Canadian Lynx. (North American animals also in car names)

Answer 2

1. fly
2. plant sex
3. scale
4. predatory