Life Science Investigation

1. Two students decided to investigate the effect of different concentrations of sulphur dioxide on the germination of oats seeds. They set up trays of germinating seeds under a clear plastic cover along with five different concentrations of sodium disulphate (IV) solution. 

Sodium disulphate(IV) breaks down to release sulphur dioxide into the atmosphere. 

The table below shows the results after one week. 

1.1. Formulate a possible hypothesis for this investigation. (2)
1.2 State the independent variable in this investigation. (1)
1.3 Name TWO factors which might affect seed germination and which  must be kept constant. (2)
1.4 Why was the investigation repeated five times at each  concentration? (2)
1.5 Calculate the percentage of germination using a 0,10% concentration of sodium disulphate(IV). (2)
1.6 What evidence from the results in the table shows that sodium disulphate(IV) does affect the germination of oats seeds? (2)
1.7 Draw a conclusion for this investigation from the results provided. (2)

Answers

1.1 An increase/decrease in the concentration of sodium disulphate will result in an increase/decrease in the percentage germination of oats seeds

OR

An increase/decrease in the concentration of sodium disulphate Will have no effect on the percentage germination of oats seeds

1.2. Concentration of sodium disulphate (IV)

1.3. Temperature
        Water
1.4. Average estimate increases reliability

1.5.     12+13+14+11+123/ 62/100 = 62%

1.6. When oats seeds were germinated in 0,00% concentration of sodium disulphate germination percentage was high compared to when germinated in 2,50% concentration of sodium disulphate

1.7. Increasing concentrations of sodium disulphate decreased the germination of oats seeds After 2.50% no seeds germinated