Question

In hyponasty, there is increased growth on
A. Shaded side
B. Illuminated side
C. Lower surface
D. Upper surface

Answer 1

Nastic movements are non-directional responses to stimuli (e.g. temperature, humidity, lightweight irradiance), and are sometimes related to plants. The movement may be because of changes in state or changes in growth.

Complete answer:
The movement of a plant structure in response to AN external stimulant within which the direction of response isn't determined by the direction of the stimulant is understood as a nastic movement. it's additionally referred to as nasties. The stimuli could also be classified as lightweight, heat, bit or contact, etc. Examples embrace the diurnal movement of leaves and also the response of insectivorous plants, like the Venus flytrap, to prey.
Petiole hyponasty is an upward movement driven by a better rate of cell growth on the lower (abaxial) compared with the higher (adaxial) aspect. Hyponasty is common among rosette species facing environmental stresses like flooding, the proximity of neighbours, or elevated close temperature. Nastic movements are responses of plant elements to stimuli. Epinasty is that the downward bending of a leaf ensuing from larger growth of the {upper side} than of the lower side. because of more growth on the top, the flower can open because of epinasty. The hyponasty is AN upward bending of leaves ensuing from magnified growth on the lower surface.
Thus, the right answer is choice C.

Note: Generally, the hyponastic response is AN upward bending of leaves or different plant elements, ensuing from accelerated only growth of the lower aspect of the petiole compared to its higher half. This will be determined in several terrestrial plants and is connected to the phytohormone ethylene.