| exam,subject,domain,context,table_1_context,table_1,question,answer | |
| naep,biology,life_biology,"Two alleles of a gene influence body colour in Drosophila. The dominant allele B results in a brown body colour while the recessive allele b codes for black body. In addition, two alleles of another gene determine wing shape; normal wings (V) are dominant over vestigial wings (v).","In a dihybrid cross between a double heterozygote for body colour and wing shape (BbVv) and a homozygous recessive for both traits (bbvv), the following offspring were obtained:","<table><tr><td>brown body, normal wings: 29</td><td>brown body, vestigial wings: 8</td></tr><tr><td>black body, normal wings: 10</td><td>black body, vestigial wings: 33</td></tr></table>",Identify the recombinant phenotypes amongst the offspring.,"brown body vestigial wings AND black body, normal wings" | |
| naep,biology,life_biology,"Two alleles of a gene influence body colour in Drosophila. The dominant allele B results in a brown body colour while the recessive allele b codes for black body. In addition, two alleles of another gene determine wing shape; normal wings (V) are dominant over vestigial wings (v).","In a dihybrid cross between a double heterozygote for body colour and wing shape (BbVv) and a homozygous recessive for both traits (bbvv), the following offspring were obtained:","<table><tr><td>brown body, normal wings: 29</td><td>brown body, vestigial wings: 8</td></tr><tr><td>black body, normal wings: 10</td><td>black body, vestigial wings: 33</td></tr></table>",Explain whether these results fit the predicted Mendelian ratios for this cross.,"a. independent assortment predicts 1:1:1:1 | |
| OR | |
| this (mendelian) ratio not seen / recombinants less frequent/parental types more frequent; | |
| b. suggests linkage | |
| OR | |
| small numbers so could be a result of differential survival;" | |
| naep,biology,life_biology,"Two alleles of a gene influence body colour in Drosophila. The dominant allele B results in a brown body colour while the recessive allele b codes for black body. In addition, two alleles of another gene determine wing shape; normal wings (V) are dominant over vestigial wings (v).","In a dihybrid cross between a double heterozygote for body colour and wing shape (BbVv) and a homozygous recessive for both traits (bbvv), the following offspring were obtained:","<table><tr><td>brown body, normal wings: 29</td><td>brown body, vestigial wings: 8</td></tr><tr><td>black body, normal wings: 10</td><td>black body, vestigial wings: 33</td></tr></table>",Outline the statistical test that could be used to provide more evidence of the type of inheritance.,"a. calculate expected numbers; | |
| b. assume no selective advantage to any of the genotypes; | |
| c. calculate chi square value; | |
| d. (if tabulated value is exceeded then) significant difference/reject null hypothesis/alleles do not sort independently/alleles linked;" | |
| ib,chemistry,measurement_data_processing,"Hypochlorous acid, HOCl, is a sterilizing agent used in swimming pools and is produced when chlorine reacts with water. | |
| $$\mathrm{Cl}_2(\mathrm{aq}) + \mathrm{H}_2\mathrm{O}(\mathrm{l})\rightleftharpoons \mathrm{HOCl}(\mathrm{aq}) + \mathrm{HCl}(\mathrm{aq})$$",Researchers studying the solubility of chlorine in pure water at different temperatures compile the following data from different sources.,<table><tr><td>Source</td><td>Temperature / °C</td><td>Solubility of chlorine</td></tr><tr><td>A</td><td>0</td><td>1.46 g per 100 cm³</td></tr><tr><td>B</td><td>10</td><td>310 cm³ per 100 cm³</td></tr><tr><td>C</td><td>20</td><td>0.70 g per 100 cm³</td></tr><tr><td>D</td><td>25</td><td>6300 mg per 1000 cm³</td></tr><tr><td>E</td><td>30</td><td>177 cm³ per 100 cm³</td></tr><tr><td>F</td><td>30</td><td>0.57 g per 100 cm³</td></tr></table>,(i) Identify a problem in comparing the data from different sources.,"Any one of: | |
| pressure not given | |
| use of different units | |
| OR | |
| different ways of measuring | |
| OR | |
| different precisions/significant figures | |
| OR | |
| uncertainties not given" | |
| ib,chemistry,redox,"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.","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) (i) Deduce the oxidation state of cobalt in [Co(NH₃)₅Cl]Cl₂ and the charge of the complex ion.,"Oxidation state: +3 | |
| Charge of complex ion: 2+" | |
| 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.","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) (ii) Describe the bonding of chloride ions in [Co(NH₃)₄Cl₂]Cl.,"two chlorides covalently bonded/coordination bond to cobalt ion | |
| one chloride ionically bonded to complex ion" | |
| 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.","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) (iii) Explain why these complex ions are coloured.,"3d sub-level split in presence of ligands | |
| light is absorbed when electrons promoted between split-levels | |
| colour seen is complementary to the light absorbed" | |