Final answer:
Olfaction in vertebrates involves approximately 1,000 types of receptors. Humans have about 350 olfactory receptor subtypes that allow us to sense about 10,000 different odors.
Step-by-step explanation:
The answer to the question 'Olfaction in vertebrates involves approximately how many types of receptors?' is c. 1,000. Humans have about 350 olfactory receptor subtypes that work in various combinations to allow us to sense about 10,000 different odors.
On the other hand, mice have about 1,300 olfactory receptor types, indicating that they probably sense more odors than humans. The number of olfactory receptor types varies among different vertebrate species, and in general, they have a higher number of receptor types than humans.