All are true regarding smell sence EXCEPT

B. i.e. (Affects the larger area) (185- 86 - Ganong 22nd) (219-22-Ganong 23rd)SMELL - In dogs and other animals in which the sense of smell is highly developed (Macrosmatic animals) thearea covered by olfactory mucous membrane is larger; in Microsmatic animals such as humans it is small*** Olfactory receptors are phasic receptors and adapt very rapidly within first second the adaptation occurs upto 50%.* The olfactory receptor cell is a bipolar neuron. The dendrite of this neuron is short* Methyl mercaptan produces olfactory sensation even at a low concentration of 0.0000004 mg/L of air (Low threshold for olfactory stimulation)* Adaptation to the smell of odoriferous substances is called olfactory fatigue. An odour (foul or pleasant) which at first is quite clearly perceptible, gradually disappears and becomes imperceptible. It develops within second or minute, depending on the nature of the substances* The degree of adaptation can be measured by the rise in threshold concentration required to excite the sense of smell (1091 -A.K. Jain 3rd)* Olfactory threshold increases with advancing age