AP BIOLOGY

Detailed explanation-1: -There are more than 220 million ORs in the canine nasal cavity, which allow a vast number of odorants to bind (12). There is only one type of OR per ORC, and odor intensity is proportional to the number of ORC activated; ORC also have receptors for hormones and neurotransmitters.

Detailed explanation-2: -They have more than 100 million sensory receptor sites in the nasal cavity compared to 6 million in people, and the area of the canine brain devoted to analyzing odors is about 40 times larger than the comparable part of the human brain.

Detailed explanation-3: -The olfactory acuity of the dog, which can detect odorant concentration levels at 1–2 parts per trillion, is roughly 10, 000–100, 000 times that of the human.

Detailed explanation-4: -Depending on the breed, dogs have up 100 million or more scent receptors in their noses. And those terrific trackers we know as Bloodhounds have 300 million! Dogs can detect some smells in parts per trillion.

Detailed explanation-5: -Researchers have estimated that a bloodhound’s nose consists of approximately 230 million olfactory cells, or “scent receptors”-40 times the number in humans.