Melatonin is secreted by……gland.
a) thymus
b) pineal
c) thyroid
d) anterior pituitary
When the secretion of melatonin at peak?
a) at dawn
b) at noon
c) at dusk
d) at night
All plant behaviors are…….
a) innate
b) learned
c) both
d) none
……..is a directional movement toward or away from a stimulus.
a) tropism
b) taxis
c) nastic
d) turgor
……..is a growth movement related to the direction of a stimulus.
a) tropism
b) taxis
c) nastic
d) turgor
The roots grow vertically downward is…
a) photonastic
b) geotropism
c) phototropism
d) epinasty
