What are the major differences between the anterior and posterior pituitary?

Anterior pituitary:

The anterior pituitary has been originated from the Rathke's pouch. Several  different hormones are released  from the anterior pituitary. The hormones of anterior pituitary is synthesized in the anterior pituitary. The blood is supplied by the superior hypophyseal nerves. Both the releasing and inhibitory hormones controlled the anterior pituitary.

Posterior pituitary:

Posterior pituitary has been originated by the hypothalamic neural tissue. Only two hormones are released from the posterior pituitary. The hormones are synthesized in the hypothalamus and released by the posterior pituitary. The blood is supplied by the inferior hypophyseal nerves. The posterior pituitary is controlled by the neural signals.

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.