What stimuli are receptors in the nose and tongue sensitive to?

Why has two different alleles for the same trait?

Science which of the following is an example of a cyclic behavior that is seasonal? i think the answer is d, i just need to double check : ). a. running from predators. b. searching for water. c. hunting at night. d. migrating for warmth. ***

Are gametes exactly the same? explain why or why not?