Final answer:
Cedar wood's distinct smell comes from cedarwood oils, including compounds like cedrol and thujopsene, whereas Nigella sativa has a different set of oils contributing to its cedar-like smell. Esters and aldehydes in plants are often behind their unique odors.
Step-by-step explanation:
The distinctive smell of cedar wood is largely due to a group of chemicals known as cedarwood oils. These oils contain compounds like cedrol and thujopsene. Although certain aromatic compounds are common between different species, the chemical that imparts the cedar-like smell to Nigella sativa (also known as black cumin) is not the same as the chemicals found in cedar wood.
Instead, Nigella sativa contains a different set of oils and compounds that contribute to its characteristic odor. In plant chemistry, esters and aldehydes like cinnamaldehyde and vanillin are responsible for many distinct plant odors and flavors.