exam,subject,domain,context,image_1_context,image_1,table_1_context,table_1,question,answer
naep,biology,life_biology,"Duckweed (Lemna minor) is a small flowering plant that floats on water. Duckweed can reproduce rapidly using asexual reproduction, giving rise to dense populations. A group of students investigated the effect of temperature on the rate of population growth of duckweed. They set up three culture dishes using 500ml of filtered pond water with a pH of 7.0. The culture dishes were given a small starting population of plants and each dish was incubated at a fixed temperature (15, 20 or $25^{\circ}\mathrm{C}$ ). The number of duckweed plants in each dish was counted over several weeks. The data are summarized in the table.",The micrograph shows a transverse section of a leaf from a flowering plant.,images/b2deabe453910c5d.jpg,The data are summarized in the table.,"<table><tr><td>Time / weeks</td><td colspan=""3"">Number of plants at a given temperature</td></tr><tr><td></td><td>15℃<br>±1℃</td><td>20℃<br>±1℃</td><td>25℃<br>±1℃</td></tr><tr><td>0</td><td>5</td><td>5</td><td>5</td></tr><tr><td>1</td><td>10</td><td>14</td><td>15</td></tr><tr><td>2</td><td>31</td><td>37</td><td>50</td></tr><tr><td>3</td><td>38</td><td>76</td><td>80</td></tr><tr><td>4</td><td>24</td><td>115</td><td>117</td></tr><tr><td>5</td><td>23</td><td>168</td><td>177</td></tr></table>",(a) Outline what indicates that temperature is the independent variable in this experiment. [1],actively varied / manipulated (by the experimenter) / OWTTE;
naep,biology,life_biology,"Duckweed (Lemna minor) is a small flowering plant that floats on water. Duckweed can reproduce rapidly using asexual reproduction, giving rise to dense populations. A group of students investigated the effect of temperature on the rate of population growth of duckweed. They set up three culture dishes using 500ml of filtered pond water with a pH of 7.0. The culture dishes were given a small starting population of plants and each dish was incubated at a fixed temperature (15, 20 or $25^{\circ}\mathrm{C}$ ). The number of duckweed plants in each dish was counted over several weeks. The data are summarized in the table.",The micrograph shows a transverse section of a leaf from a flowering plant.,images/b2deabe453910c5d.jpg,The data are summarized in the table.,"<table><tr><td>Time / weeks</td><td colspan=""3"">Number of plants at a given temperature</td></tr><tr><td></td><td>15℃<br>±1℃</td><td>20℃<br>±1℃</td><td>25℃<br>±1℃</td></tr><tr><td>0</td><td>5</td><td>5</td><td>5</td></tr><tr><td>1</td><td>10</td><td>14</td><td>15</td></tr><tr><td>2</td><td>31</td><td>37</td><td>50</td></tr><tr><td>3</td><td>38</td><td>76</td><td>80</td></tr><tr><td>4</td><td>24</td><td>115</td><td>117</td></tr><tr><td>5</td><td>23</td><td>168</td><td>177</td></tr></table>",(b) Identify the temperature that gives the highest overall population growth rate over the experimental period. [1],25℃;
naep,biology,life_biology,"Duckweed (Lemna minor) is a small flowering plant that floats on water. Duckweed can reproduce rapidly using asexual reproduction, giving rise to dense populations. A group of students investigated the effect of temperature on the rate of population growth of duckweed. They set up three culture dishes using 500ml of filtered pond water with a pH of 7.0. The culture dishes were given a small starting population of plants and each dish was incubated at a fixed temperature (15, 20 or $25^{\circ}\mathrm{C}$ ). The number of duckweed plants in each dish was counted over several weeks. The data are summarized in the table.",The micrograph shows a transverse section of a leaf from a flowering plant.,images/b2deabe453910c5d.jpg,The data are summarized in the table.,"<table><tr><td>Time / weeks</td><td colspan=""3"">Number of plants at a given temperature</td></tr><tr><td></td><td>15℃<br>±1℃</td><td>20℃<br>±1℃</td><td>25℃<br>±1℃</td></tr><tr><td>0</td><td>5</td><td>5</td><td>5</td></tr><tr><td>1</td><td>10</td><td>14</td><td>15</td></tr><tr><td>2</td><td>31</td><td>37</td><td>50</td></tr><tr><td>3</td><td>38</td><td>76</td><td>80</td></tr><tr><td>4</td><td>24</td><td>115</td><td>117</td></tr><tr><td>5</td><td>23</td><td>168</td><td>177</td></tr></table>",(c) Explain how temperature can influence population growth in a species such as Lemna minor. [2],"a. temperature is a limiting factor (for enzymes)
; OR
; other limiting factors are influenced by temperature
; OR
; temperature is closer to the optimum temperature (of the enzymes);
; b. at higher temperature exchange of materials is more efficient;"
naep,biology,life_biology,"Duckweed (Lemna minor) is a small flowering plant that floats on water. Duckweed can reproduce rapidly using asexual reproduction, giving rise to dense populations. A group of students investigated the effect of temperature on the rate of population growth of duckweed. They set up three culture dishes using 500ml of filtered pond water with a pH of 7.0. The culture dishes were given a small starting population of plants and each dish was incubated at a fixed temperature (15, 20 or $25^{\circ}\mathrm{C}$ ). The number of duckweed plants in each dish was counted over several weeks. The data are summarized in the table.",The micrograph shows a transverse section of a leaf from a flowering plant.,images/b2deabe453910c5d.jpg,The data are summarized in the table.,"<table><tr><td>Time / weeks</td><td colspan=""3"">Number of plants at a given temperature</td></tr><tr><td></td><td>15℃<br>±1℃</td><td>20℃<br>±1℃</td><td>25℃<br>±1℃</td></tr><tr><td>0</td><td>5</td><td>5</td><td>5</td></tr><tr><td>1</td><td>10</td><td>14</td><td>15</td></tr><tr><td>2</td><td>31</td><td>37</td><td>50</td></tr><tr><td>3</td><td>38</td><td>76</td><td>80</td></tr><tr><td>4</td><td>24</td><td>115</td><td>117</td></tr><tr><td>5</td><td>23</td><td>168</td><td>177</td></tr></table>",(d) Suggest how the reliability of this investigation could be improved. [1],a. (larger culture dishes with) bigger starting duckweed populations;
ib,chemistry,bonding_structure,"Hydrochloric acid is an important chemical reactant and industrial chemical.
A pH probe is placed in a small volume of 0.10 mol dm⁻³ solution of hydrochloric acid. The pH is recorded while a steady stream of distilled water is added to the acid at constant temperature.",Use the colour wheel and the electromagnetic spectrum in sections 5 and 15 of the data booklet.,images/273814e8f4cdd2f9.jpg,"Lithium carbide, Li2C2, is one of many compounds of lithium and carbon. The formulas and colours of three compounds of cobalt are:",<table><tr><td>Compound</td><td>Colour</td></tr><tr><td>[Co(NH3)6]Cl3</td><td>orange-yellow</td></tr><tr><td>[Co(NH3)5Cl]Cl2</td><td>purple</td></tr><tr><td>[Co(NH3)4Cl2]Cl</td><td>green</td></tr></table>,"(b) (iv) State and explain, in which of the complex ions, the electron transitions responsible for the colour require the highest energy. Use the colour wheel and the electromagnetic spectrum in sections 5 and 15 of the data booklet.","complex [Co(NH3)6] Cl3
absorbs blue-purple light/wavelength 424 nm/shortest wavelength/highest energy"