A flower which can be divided into two equal halves by only one plane is
zygomorphic
actinomorphic
regular
perfect
Calcium level decreases in the blood due to hyposecretion of
parathyroid hormone
calcitonin
thyroxine
adrenaline
A.
parathyroid hormone
Parathormone is secreted from parathyroid gland. It helps to regulate the metabolism of calcium and certain other minerals like phosphate. Combined effect of parathormone and calcitonin normally maintain the blood calcium level.