What is the signal for a vesicle storing peptide hormone to move to the plasma membrane and release contents of vesicle?
a. activation of an integrin receptor
b. activation of a g-protein
c. activation of an enzyme linked receptor
d. increase in [ca++]i
e. increase in [na+]i

(d). Increase in [Ca++]i

Explanation:

Peptide hormones are hormones, synthesized by polymerization of amino acids that generally bind with receptors present on membrane of target cells. These hormones are produced in ER (endoplasmic reticulum) and are packed into secretory vesicles in Golgi for export.

These peptide hormone storing vesicles move to membrane of target cell and release their content due to increase in intracellular calcium (Ca++) ions concentration.

Thus, the correct answer is option (d).

the scientific method.

the correct answer is: b. pantala flavescens, because these organisms would have a high level of genetic variation due to sexual reproduction.  

because involves two organisms (parents) whose genetic material combines, sexual reproduction leads to genetic variation in new generations of offspring. the offspring is an unique organism, with new genome, more protected with the higher ability to adapted. this process is fundamental to evolution.