Growth and Movement in Plants

Transcript

What are Shoot and Root? Shoot is the part of plant that grows above ground Root is the part of plant that grows underground Shoot Root Important Points about Shoot Shoot always grow in Upward Direction and towards light Even if Plant is kept upside down, shoot bends and grows upward Important Points about Root Roots always grow in Downward Direction and grow away from light Even if Plant is kept upside down, roots bends and grows downward Activity 10.3Take some bean or gram seeds and allow them to germinate on a moist cloth or a moist tissue paper. Let them germinate until each of them develop into a seedling having a small root and a small shoot. Now, take three glass beakers or tumblers, and label them as A, B and C. Take three glass plates and attach a thick blotting paper to one side of each plate using a thick soft cotton thread. Fix one seedling on each plate using a thick soft cotton thread, as shown in Fig. 10.2, ensuring that the plant is not damaged. Activity 10.3Now, place one glass plate upright with a seedling attached into each of the beaker A and beaker C, as shown in Fig. 10.2a and Fig. 10.2c. In beaker B, arrange the plate such that the shoot of a seedling is directed downwards and the root is directed upwards, as shown in Fig. 10.2b Pour water into all the three beakers to ensure that the seedling in each beaker remains above the water level. In each case, let the bottom of the blotting paper get completely wet by soaking in the water. In this way, the seedling will get the moisture from the wet blotting paper. Activity 10.3Place beaker A and beaker B in sunlight as shown in Fig. 10.2a and Fig. 10.2b. Position beaker C as shown in Fig. 10.2c. Place a cardboard box in such a way that the seedling gets light from one direction only through a small circular hole. Upright plant kept in sunlight from all directions (a)ObservationsWe observed that :- When the plant is kept upright, the root grows downwards and the shoot grows upwards. When the plant is kept inverted, the root bends and grows downwards. Also, the shoot bends and grows upwards. When the plant gets sunlight only from one direction, the shoot grows in the direction of light while the root continues to grow downwards. Table 10.3Fill Table 10.3 with your predictions and observations Table 10.3: Growth of root and shoot under different conditions Beakers Direction of sunlight Direction of plant Direction of growth of root and shoot Shoot/ Root Predictions Observations A All directions Upright Shoot Upwards Upwards Root Downwards Downwards B All directions Inverted Shoot Downwards Upwards Root Upwards Downwards C Only from one direction Upright Shoot Upwards Towards the Light Root Downwards Away from the Light