AS & A Level Biology - 9700 Paper 3 2016 Summer Zone 3

(a) When carrying out a practical procedure the hazards of using the solutions need to be considered. Then the level of risk needs to be assessed as low or medium or high.

State the hazard with the greatest level of risk when using the solutions then state the level of risk of the procedure: low or medium or high.

hazard ..............................................................................................................
level of risk ........................................................................................................[1]

(b) You are required to keep a sample of 10 $cm^3$ of the solution in $P$ to test at the temperature of the room.

Then heat the remaining solution in $P$ and remove 10 $cm^3$ samples of the solution at different temperatures including a sample at the $maximum$ temperature of 70 $^{\circ}C$.

(i) Use the thermometer to measure the temperature of the room.

temperature ........................................................[1]

(ii) You will need to test a sample of the solution in $P$ which has been heated to 70 $^{\circ}C$.

State the other temperatures at which you will remove each sample.

..............................................................................................................................
...............................................................................................................................[2]

(iii) Prepare the space below and record your results.[6]

(iv) Identify two significant sources of error in this investigation.

...............................................................................................................................................
................................................................................................................................................
................................................................................................................................................
..............................................................................................................................[2]

(v) Explain how the enzyme catalase was affected by the change in temperature.

...............................................................................................................................................
................................................................................................................................................
................................................................................................................................................
..............................................................................................................................[2]

(vi) This procedure investigated the effect of temperature on the activity of catalase in the plant extract.

To modify this procedure for investigating another variable, the independent variable (temperature) would need to be standardised.

Describe how the temperature could be standardised.

...............................................................................................................................................
.......................................................................................................................................

Now consider how you could modify this procedure to investigate the effect of the $concentration$ of catalase in the plant extract on the breakdown of hydrogen peroxide.

Describe how this independent variable, $concentration$ of catalase, could be investigated.

...............................................................................................................................................
................................................................................................................................................
...............................................................................................................................................
..............................................................................................................................[3]

(c) A student investigated the activity of catalase in plant extracts from different species of plants, $R$, $S$, $T$, $U$ and $V$, by measuring the initial rate of activity.

Table 1.1 shows the results for this investigation.

$$\begin{array}{|c|c|} \hline different & initial \text{rate of} activity \\ plant species & \text{of catalase} \, / \, s^{-1} \\ \hline R & 0.0750 \\ S & 0.1275 \\ T & 0.0900 \\ U & 0.0325 \\ V & 0.0625 \\ \hline \end{array}$$

You are required to use a sharp pencil for charts.

Plot a chart of the data shown in Table 1.1.

[4]

(a) When carrying out a practical procedure the hazards of using the solutions need to be considered. Then the level of risk needs to be assessed as low or medium or high.

State the hazard with the greatest level of risk when using the solutions then state the level of risk of the procedure: low or medium or high.

hazard ..............................................................................................................
level of risk ........................................................................................................[1]

(b) You are required to keep a sample of 10 $cm^3$ of the solution in $P$ to test at the temperature of the room.

Then heat the remaining solution in $P$ and remove 10 $cm^3$ samples of the solution at different temperatures including a sample at the $maximum$ temperature of 70 $^{\circ}C$.

(i) Use the thermometer to measure the temperature of the room.

temperature ........................................................[1]

(ii) You will need to test a sample of the solution in $P$ which has been heated to 70 $^{\circ}C$.

State the other temperatures at which you will remove each sample.

..............................................................................................................................
...............................................................................................................................[2]

(iii) Prepare the space below and record your results.[6]

(iv) Identify two significant sources of error in this investigation.

...............................................................................................................................................
................................................................................................................................................
................................................................................................................................................
..............................................................................................................................[2]

(v) Explain how the enzyme catalase was affected by the change in temperature.

...............................................................................................................................................
................................................................................................................................................
................................................................................................................................................
..............................................................................................................................[2]

(vi) This procedure investigated the effect of temperature on the activity of catalase in the plant extract.

To modify this procedure for investigating another variable, the independent variable (temperature) would need to be standardised.

Describe how the temperature could be standardised.

...............................................................................................................................................
.......................................................................................................................................

Now consider how you could modify this procedure to investigate the effect of the $concentration$ of catalase in the plant extract on the breakdown of hydrogen peroxide.

Describe how this independent variable, $concentration$ of catalase, could be investigated.

...............................................................................................................................................
................................................................................................................................................
...............................................................................................................................................
..............................................................................................................................[3]

(c) A student investigated the activity of catalase in plant extracts from different species of plants, $R$, $S$, $T$, $U$ and $V$, by measuring the initial rate of activity.

Table 1.1 shows the results for this investigation.

$$\begin{array}{|c|c|} \hline different & initial \text{rate of} activity \\ plant species & \text{of catalase} \, / \, s^{-1} \\ \hline R & 0.0750 \\ S & 0.1275 \\ T & 0.0900 \\ U & 0.0325 \\ V & 0.0625 \\ \hline \end{array}$$

You are required to use a sharp pencil for charts.

Plot a chart of the data shown in Table 1.1.

[4]

K1 is a slide of a stained transverse section through a plant leaf.
You are not expected to be familiar with this specimen.

You are required to use a sharp pencil for drawings.

(a) (i) Draw a large plan diagram of the part of the leaf as shown by the shaded area in Fig. 2.1,
to include observable features and two vascular bundles.


Fig. 2.1

You are expected to draw the correct shape and proportions of the different tissues. [4]

(ii) Observe the epidermis in K1. These cells are not identical.

Select one group of four adjacent (touching) cells which show some of the differences between these cells.

Make a large drawing of this group of four cells.
Each cell of the group must touch at least one other cell.

Use one ruled label line and label to identify the cell wall of one cell. [5]

(c) Prepare the space below so that it is suitable for you to record observable differences between
the leaf on K1 and the leaf in Fig. 2.2.

Record your observations in the space you have prepared. [4]

K1 is a slide of a stained transverse section through a plant leaf.
You are not expected to be familiar with this specimen.

You are required to use a sharp pencil for drawings.

(a) (i) Draw a large plan diagram of the part of the leaf as shown by the shaded area in Fig. 2.1,
to include observable features and two vascular bundles.


Fig. 2.1

You are expected to draw the correct shape and proportions of the different tissues. [4]

(ii) Observe the epidermis in K1. These cells are not identical.

Select one group of four adjacent (touching) cells which show some of the differences between these cells.

Make a large drawing of this group of four cells.
Each cell of the group must touch at least one other cell.

Use one ruled label line and label to identify the cell wall of one cell. [5]

(c) Prepare the space below so that it is suitable for you to record observable differences between
the leaf on K1 and the leaf in Fig. 2.2.

Record your observations in the space you have prepared. [4]