Which of the following brain components could cause a patient to suffer imbalances in several hormones in his body at once?

the pituitary gland
the thyroid gland
the brain stem
the frontal lobe

Cattle with brown fur and cattle with white fur will produce a reddish roan calf . when examined closely, the calf show about an even number of brown hairs and white hairs that give a reddish appearance when viewed from far away. the fact that both the brown fur allele and the white fur allele are expressed equally in the offspring is an example of