BOOKS4BIO

Plant movements are mainly divided in two parts – 1.Movements of Locomotion 2.Movements of Curvature 1. Movements of Locomotion – In this type of movement Plant’s whole body or a part of plant goes from one place to another. In short plant changes its position, is called movements of locomotion. This type of movements is also divided in two types – I. Autonomous Movements – This type of movements is induced by internal stimuli. It is divided in 3 parts – A. Amoeboid - e.g. Gametes of Spirogyra B. Ciliary - e.g. Gametes of Chlamydomonas C. Cyclosis –          a. Rotation – When protoplasm moves around the central vacuole.           e.g. Hydrilla, Vallisneria           b. Circulation – When protoplasm moves randomly in cell.           e.g. Tradescantia II. Induced or Para tonic Movements – It is induced by External stimuli. It is also divided in 3 types – A. Chemo-tactic – e.g. Anthaloziades B. Photo-tactic – e.g. Eye spot in algae C. Thermo-

Photoperiodism –       Effect of sunlight on plant’s flowering is called photoperidism. It is studied by Garner & Allard in Maryland & Soybean. Plants are mainly divided in 3 types on the basis of photoperiodism – 1.SDP (Short Day Plants) – In this type we include such plants which needs less sunlight than critical photo period. SDPs need critical photo period or less than it for flowering. So dark phase is very important for SDPs. So these plants are also called LNP (Long Night Plants). If dark phase is replaced by red light, the flowering can’t be done in such plants. Examples – Tobacco, Soya bean, Viola, Xanthium, Chrysanthemum, Cannabis, Chenopodium, Mustard, Dahlia, Rice, Sugarcane. 2.LDP (Long Day Plants) –   Which plants need sunlight more than critical photo period, is called LDPs. These plants also called SNP (Short Night Plants), because Light phase is more important than dark phase for these plants. Examples – Barley, Avena, Potato, Radish