Phototropism vs Photoperiodism
Similarities and Differences between Phototropism and Photoperiodism in Plants
Phototropism: Phototropism is the growth or movement of plants (or any organism) in response to light. Phototropism can be of two different types – (1) Positive Phototropism – movement towards the source of light, (2) Negative phototropism – movement away from the light. Negative phototropism is also called as Skototropism.
Photoperiodism: Photoperiodism is the response of plants (or any organism) to the lengths of dark and light periods in a day. The changes in the duration of light and dark periods in a day are called photoperiods. In plants, the photoperiodism induces flowering.
The present post discusses the Similarities and Differences between Phototropism and Photoperiodism
Similarities between Phototropism and Photoperiodism
Ø Light has a significant role in both phototropism and photoperiodism.
Ø Phototropism and photoperiodism are present in both plants and animals.
Ø Both processes require photoreceptors to accept the light stimuli.
Ø Both processes are orchestrated by hormones.
Difference between Phototropism and Photoperiodism
Sl. No. Phototropism Photoperiodism
1 Phototropism is a movement of curvature in plants caused by the light. Photoperiodism is the induction of flowering in response to the duration of light and dark periods in a day (photoperiods).
2 Phototropism induces curvature in plant parts. Photoperiodism induce flowering in plants.
3 Phototropism occurs when the light falls on the plant from one direction. Photoperiodism occurs irrespective of the direction of the light.
4 The stimuli of phototropism are perceived by the apical meristem. The stimuli of photoperiodism are perceived by the leaves.
5 Carotenoids (yellow coloured pigments) acts as the photoreceptors in the phototropism. Phytochromes (blue coloured pigments) act as the photoreceptors in photoperiodism.
6 The phototropism is caused by the differential growth of an organ in the zone of elongation. The photoperiodism is caused by the conversion of a vegetative bud into a floral bud.
7 Phototropism is mediated through the hormone Auxin. Photoperiodism and induction of flowering are mediated through Cytokinins and Gibberellins.
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