"initialQuestionWindow":[{"id":"71db4373-2416-4c62-bd78-2887365264bc","revisionId":"c445b10a-3d2f-4d79-bb20-239a84e2b345","questionNumber":null,"questionType":"LA","specification":"","difficulty":3,"difficultyBand":"easy","totalMarks":9,"sourceTitle":null,"calculatorUse":null,"parts":[{"id":"c3b77893-2fa4-47cb-bec7-1d39594de9bc","label":"a","content":"### Cells contain different specialized structures.\n\nComplete the sentences below using structures from this list:\n\ncell membrane** | **mitochondria** | **ribosomes** | **cytoplasm** | **chloroplast\n\n1. The structures where aerobic respiration occurs to release energy for the cell are the ** **.\n2. The barrier that controls the movement of substances into and out of the cell is the ** **.\n3. The tiny structures responsible for protein synthesis are the ** **.","markscheme":"- **mitochondria** B1\n- **cell membrane** B1\n- **ribosomes** B1","marks":3,"order":0,"markingRubric":null,"explanation":{"methods":[{"id":"match_structure_function","label":"Match structure to function","steps":[{"type":"text","order":0,"title":"Match respiration","content":"Look for the clue **“aerobic respiration”**. In cells, aerobic respiration releases energy in the **mitochondria**.\n\nSo sentence 1 is completed with **mitochondria**. This earns the first B1 mark.","highlights":[{"text":"The structures where aerobic respiration occurs to release energy for the cell are the ** **.","location":"specification"}]},{"type":"text","order":1,"title":"Identify the barrier","content":"The structure that forms the cell’s outer boundary and controls what enters and leaves is the **cell membrane**.\n\nSo sentence 2 is completed with **cell membrane**. This earns the second B1 mark.","highlights":[{"text":"The barrier that controls the movement of substances into and out of the cell is the ** **.","location":"specification"}]},{"type":"text","order":2,"title":"Match protein synthesis","content":"**Protein synthesis** means making proteins. The tiny cell structures that make proteins are **ribosomes**.\n\nSo sentence 3 is completed with **ribosomes**. This earns the final B1 mark.","highlights":[{"text":"The tiny structures responsible for protein synthesis are the ** **.","location":"specification"}]}]}],"generatedAt":"2026-07-22T12:06:11.595Z","modelVersion":"gpt-5.6-terra+diagrams-1","explanationVersion":"v3"},"options":[]},{"id":"58238bf0-f544-4f8f-b469-6641d144b9fc","label":"b","content":"### A student uses a light microscope to study plant cells.\n\nOne of the cells drawn by the student is shown in **Fig. 16.1**.\n\n![A detailed line drawing of a rectangular plant cell. A double-headed arrow spanning horizontally across the longest dimension of the cell is labeled '120 mm'. Inside the cell, there is a prominent circular nucleus, several chloroplasts, and a large central vacuole.](https://assets.mathsgenie.co.uk/aqa-qb/4feb8292-5d67-4f1c-980b-2c43292c2574.png)\n\nFig. 16.1\n\n(i) The actual length of this plant cell is \$0.08\\text{ mm}\$.\n\nCalculate the magnification of the student's drawing.\n\nUse the equation: \$\\text{magnification} = \\text{measured size} \\div \\text{actual size}\$\n\nMagnification = \$\n\\times\$ ** **\n\n(ii) What type of substance is added to microscope slides to colour the cell structures and make them easier to see?","markscheme":"- Substitutes into equation: $\\frac{120}{0.08}$ M1\n- Evaluates to $\\times 1500$ A1\n- **stain** or **dye** (accept specific examples such as iodine solution or methylene blue) B1","marks":3,"order":1,"markingRubric":null,"explanation":{"methods":[{"id":"magnification_and_staining","label":"Calculate and identify","steps":[{"type":"text","order":0,"title":"Read the two sizes","content":"For the drawing, use the labelled length $120\\text{ mm}$. The actual cell length is $0.08\\text{ mm}$.\n\nBoth measurement

Cell structures

Question 19

Cell structures Questions

Cell structures

Question 19

Cell structures Questions