Some reptiles, like snakes, have olfactory receptors
on their tongues,
on the roof of their mouths,
on their skin,
at the tip of their tails

The correct answer for the fill in the blank is- On the roof of their mouths.

Some reptiles like snake possesses Vemeronasal organ ( a sense organ used for smell) that is also termed as Jacobson's organ. It is located in the nasal cavity that is present just above the roof of the mouth. It has olfactory receptors that detect specific organic compounds from their surroundings ( such as sex pheromones from their mating partners). They help in producing appropriate behavioral response in them.

•there must be variation for the particular trait within a population.

•the variation must be inheritable (that is, it must be capable of being passed on from the parents to their offspring).

•individuals with one version of the trait must produce more offspring than those with a different version of the trait.good

explanation:

airlines i think? or a cruise boat? does this work out for u? ?