Page 119 - Photosynthesis: The Green Miracle

Harun Yahya

The Fascinating Movements of Leaves
As you saw in the preceding section, plants have been equipped with
systems that perceive light, pressure, and flavors, as if they were human

beings. When these senses are considered one by one, they can be seen to
possess a perfect design. The various movement, growth and defense
mechanisms that emerge as a result of these systems in the plant exhibit
important evidence of creation.
Plants attached to the soil by their roots are not completely motion-
less. Mechanisms within the plant not yet been fully understood permit it
to react in line with its needs. Plants display movements in order to reach
light, water and nutrients, as if they see without eyes and touch without
hands. Each reaction has its own particular system and design. Special en-

zymes, hormones and tissues control these systems, designed to provide
maximum development.
One of the main factors that influences plants’ movement is their
sensitivity to light. The light sensitivity in sprouts, known as phototropism
(turning towards the light), is akin to the special sensitivity to visible light
in the human eye. As in all sensory systems, the first phenomenon to take
place is the perception of the stimulus. The only way for light to be per-

ceived is its absorption by pigments. The energy obtained during the ab-
sorption process is turned into chemical energy, to be used later to oper-
ate other systems. The light-sensitive system in the plant sprout consists
of two phases: in the first phase, mechanisms turn the light into electrical
and chemical signals. In the second response phase, the systems needed
for the growth of the shoot are activated, and the plant turns in the direc-
tion of the light. 53

Plant Movements

Plants move in different ways under different conditions. All move-
ments, however, are controlled by hormones such as auxin, gibberellin
and cytokinin. The way in which these substances work has not yet been

117