QUESTION 4 15 marks A number of ungerminated hemp seeds were

QUESTION 4 (15 marks) A number of ungerminated hemp seeds were to determine the amounts of protei analysed fat, starch, cellulose, other organic substances, and inorganic constituents present. Analyse were also carried out on equal numbers of seedlings six and nine days after germination. The results of the analyses are given in the table below, as percentages. Fat Protein Starch Cellulose other inorganic Loss in organic substance weight substances N/A 23 Seeds 33 24 0 15 6 day old 18 23 15.1 seedlings 9 day old 16 23.5 16.6 6.9 seedlings Discuss briefly the changes which took place during germination.

Solution

Rate of respiration is dependent on four factors :

1) Speed of air/wind

2) Surrounding temperature

3) Humidity

4) Sunlight

--> Increase in the speed of wind does not allow the air around the leaf to absorb moisture, thus decreasing the rate of transpiration. Thus, conversely, gentle breeze has a relatively higher rate of transpiration.

--> Rate of transpiration is inversely proportional to humidity surrounding the leaf. Higher concentration of humidity around the leaf will not allow the moisture in the leaves to transpire out because of large number of molecules already present in the surroundings. Thus, dry air increases the rate of transpiration and humid air decreases the rate of transpiration.

--> Temperature as a factor is directly proportional to the rate of transpiration. This means that increase in the ambient air temperature will cause the water molecules in the leaves to evaporate quickly thus increasing the rate of transpiration.

-->Sunlight decides whether a stomata is open or closed. During daytime, stomata is open and during night due to abscence of sunlight. If stomata are open, transpiration will take place, and if they are closed, transpiration will decrease. So, open stomata increase the rate of transpiration.