boiling tube containing $40\\text{ cm}^3$ of a different concentration of glucose solution.\n- Leave the cores submerged for 50 minutes.\n- Remove each core, blot with filter paper to remove excess surface liquid, and record the final mass.","difficulty":3,"difficultyBand":"easy","totalMarks":1,"sourceTitle":null,"calculatorUse":null,"parts":[{"id":"1fe05ca6-5c2b-4613-83f6-c6a2dde7af2b","label":null,"content":"State **one** variable, other than the dimensions of the turnip cores, the volume of the solution, or the immersion time, that must be controlled in this investigation to ensure valid results.","markscheme":"- Any one of:\n - Temperature of the solutions / environment B1\n - Source/variety of the turnip (or using cores from the same turnip) B1\n - Extent of peel/skin removal (ensuring all skin is completely removed from all cores) B1\n - The technique/pressure used to blot the cores dry B1\n - The species/type of turnip used B1","marks":1,"order":0,"markingRubric":null,"explanation":{"methods":[{"id":"identify_control_variable","label":"Identify a control variable","steps":[{"type":"text","order":0,"title":"Separate the variables","content":"The **glucose concentration** is the variable being changed. The cores’ mass is measured before and after, so any other factor that could affect osmosis must be kept the same for every tube.","highlights":[{"text":"a different concentration of glucose solution","location":"specification"},{"text":"record the final mass","location":"specification"}]},{"type":"text","order":1,"title":"Control the temperature","content":"Keep the **temperature of the solutions or surroundings** the same for every core. Temperature can affect the rate at which water moves by osmosis, so changing it would make the mass changes unfair to compare.\n\nThis gains the **B1** mark."}]}],"generatedAt":"2026-07-22T12:15:29.692Z","modelVersion":"gpt-5.6-terra+diagrams-1","explanationVersion":"v3"},"options":[]}],"options":[],"explanation":null,"firstAttemptFullMarks":null}],"subjectCode":"gcse_biology","summaries":[{"id":"051efef6-9dff-483b-992a-ad7401df83cc","difficultyBand":"easy","calculatorUse":null,"totalMarks":2},{"id":"063c8d7d-048d-4e30-969c-ea3b25b5aed1","difficultyBand":"medium","calculatorUse":null,"totalMarks":3},{"id":"0753bd13-d9fa-44b0-9f18-1d45b5593f20","difficultyBand":"medium","calculatorUse":null,"totalMarks":6},{"id":"0a21573e-017b-4ae9-833b-e4cd4f3e8f09","difficultyBand":"easy","calculatorUse":null,"totalMarks":1},{"id":"0a7b9af9-b280-45e8-af5e-9acdf05249de","difficultyBand":"medium","calculatorUse":null,"totalMarks":3},{"id":"11b682d1-cc57-4a4c-a745-0511633cddee","difficultyBand":"easy","calculatorUse":null,"totalMarks":2},{"id":"16d76663-beb7-4978-af81-c33b28bac5b0","difficultyBand":"easy","calculatorUse":null,"totalMarks":1},{"id":"18e5a65e-732b-416f-9cda-e539bec981c9","difficultyBand":"easy","calculatorUse":null,"totalMarks":1},{"id":"1abb6756-9c04-41a6-800c-d7335ab8a45f","difficultyBand":"medium","calculatorUse":null,"totalMarks":2},{"id":"2261df14-c473-4e10-90f5-2d0c815e7712","difficultyBand":"easy","calculatorUse":null,"totalMarks":2},{"id":"26b93e49-aa5b-4364-8f73-826c88ea18e5","difficultyBand":"easy","calculatorUse":null,"totalMarks":1},{"id":"30e13ab9-898f-494e-911c-b648725b4180","difficultyBand":"medium","calculatorUse":null,"totalMarks":1},{"id":"3e3d2c31-34f9-4628-80af-cc9a109f9613","difficultyBand":"easy","calculatorUse":null,"totalMarks":1},{"id":"408a3d68-c82a-4a4d-be3c-44633ec325fa","difficultyBand":"easy","calculatorUse":null,"totalMarks":2},{"id":"412d69c9-1e50-4933-856f-ef48770eaff8","difficultyBand":"easy","calculatorUse":null,"totalMarks":1},{"id":"4527a00f-863a-44df-a491-3e4104d93a7d","difficultyBand":"easy","calculatorUse":null,"totalMarks":2},{"id":"46058cc2-b5ac-4d70-bc65-941f83d38aa7","difficultyBand":"medium","calculatorUse":null,"totalMarks":3},{"id":"4618efaa-56ba-4b0d-8289-a1278fdf6a50","difficultyBand":"easy","calculatorUse":null,"totalMarks":1},{"id":"47b3835c-f0ca-460b-83a

Transport in and out of cells

Question 11

Transport in and out of cells Questions

Transport in and out of cells

Question 11

Transport in and out of cells Questions