An experiment to show phloem transports food
Answers
Demonstration of Upward Translocation from Germinating Seeds:
Experiment:
About 100 seeds of pea or gram or Vicia seeds are soaked in distilled water. The seeds are divided into two lots. One lot of seeds is taken out at the stage when seed coats can be removed. The fresh weight, dry weight and ash weight of this lot are determined.
(iii) The average loss or gain of the cotyledons and the shoots are separately determined.
Results:
(i) Percentage loss of dry weight and ash weight of the cotyledons and
(ii) The corresponding percentage increase of dry and ash weights of the shoot are calculated from the data.
Discussion:
The cotyledons are the storehouse of growing embryo. As the embryo grows to a seedling, reserved food material is translocated to the seedling from cotyledons. So long the leaves are not formed, photosynthesis cannot take place and seedlings remain entirely dependent on the cotyledons for their nourishment and growth.
In this experiment the seedlings are grown in dark in order to preclude the possibility of getting nourishment of the seedlings from the photosynthate.
Decrease of the food materials from the cotyledons and concomitant increase in the shoot indicates that food materials are translocated upward to the shoot at the cost of cotyledons. Some amount of food materials is lost by way of respiration or other catabolic processes in both cotyledons and shoots which may be taken here as insignificant.
Answer:
Explanation:
Experiment 1#
Demonstration of Upward Translocation from Germinating Seeds:
Experiment:
About 100 seeds of pea or gram or Vicia seeds are soaked in distilled water. The seeds are divided into two lots. One lot of seeds is taken out at the stage when seed coats can be removed. The fresh weight, dry weight and ash weight of this lot are determined.
(iii) The average loss or gain of the cotyledons and the shoots are separately determined.
Results:
(i) Percentage loss of dry weight and ash weight of the cotyledons and
(ii) The corresponding percentage increase of dry and ash weights of the shoot are calculated from the data.
Discussion:
The cotyledons are the storehouse of growing embryo. As the embryo grows to a seedling, reserved food material is translocated to the seedling from cotyledons. So long the leaves are not formed, photosynthesis cannot take place and seedlings remain entirely dependent on the cotyledons for their nourishment and growth.
In this experiment the seedlings are grown in dark in order to preclude the possibility of getting nourishment of the seedlings from the photosynthate.
Decrease of the food materials from the cotyledons and concomitant increase in the shoot indicates that food materials are translocated upward to the shoot at the cost of cotyledons. Some amount of food materials is lost by way of respiration or other catabolic processes in both cotyledons and shoots which may be taken here as insignificant.