How many chiral centers (excluding $N$ centers) are there in morphine?

The number of optically active products obtained from the complete ozonolysis of the given compound is:

Allegra,a common prescription drug with the structure shown below,is given for the treatment of seasonal allergies. How many stereogenic carbon atoms does Allegra possess?

$\alpha$-hydroxy propanoic acid has $..........$ asymmetric carbon atoms.

Which of the following would be optically active?

Which of the following combinations amongst the four Fischer projections represents the enantiomers?