Solution:
All except Stars form part of the solar system.

Solution:
All except Trypsin are chemical names of vitamins, while trypsin is an enzyme.

Solution:
All except Gandhi are founders of religions.

Solution:
In all other pairs, second is of higher intensity than the first.

Solution:
This is the only group containing no vowel.

Solution:
All except Crank are mechanical parts of a car.

Solution:
All except River contain stagnant water.