gain at least one mark. A was almost invariably correctly identified as mitochondria but B was more frequently incorrectly labelled. The most common mistake was to label it endoplasmic reticulum, without reference to ribosomes. Some candidates apparently failed to appreciate that the guideline did not point to a ribosome. (b) This question was generally not well answered with a significant number of candidates gaining no marks. Only the better candidates suggested that the different shapes were a result of sections taken of mitochondria in different positions. There were poorly expressed references to organelles being seen from different angles. Weaker candidates often gave explanations in terms of the mitochondria being specialised for different functions. (c) Most candidates gained a mark. The most common mistake was to suggest the function was transport, even after correctly naming the organelle. (d) Only the better candidates achieved full marks, with the majority gaining two. Very few linked the high numbers of mitochondria with a high rate of respiration. The most common omission was a failure to link an adaptation with the function of these cells in absorption. E2. Cell structure was generally well understood, although some candidates assumed that cell walls are a feature of eukaryotic cells and are absent from prokaryotes. The calculation was attempted by the majority of candidates, most of whom measured the scale bar and gained at least one mark. E3. (a) There were many good responses here. Most candidates could identify these organelles, although a surprising number of candidates left the answer blank. (b) In (i), many candidates explained the differences in shape by suggesting that the drawing had been done badly, or that the person doing the drawing had not observed the cell section clearly enough. However, a significant minority correctly understood that the section could have cut the organelles in different planes. In (ii), most candidates who recognised the organelles could give an acceptable answer. A few failed to obtain marks due to careless expression; such as suggesting that X ‘produces energy’, or by a simplistic answer such as ‘they produce mucus’. A few thought that Z (the Golgi body) was involved in protein synthesis.
gain at least one mark. A was almost invariably correctly identified as mitochondria but B was more frequently incorrectly labelled. The most common mistake was to label it endoplasmic reticulum, without reference to ribosomes. Some candidates apparently failed to appreciate that the guideline did not point to a ribosome. (b) This question was generally not well answered with a significant number of candidates gaining no marks. Only the better candidates suggested that the different shapes were a result of sections taken of mitochondria in different positions. There were poorly expressed references to organelles being seen from different angles. Weaker candidates often gave explanations in terms of the mitochondria being specialised for different functions. (c) Most candidates gained a mark. The most common mistake was to suggest the function was transport, even after correctly naming the organelle. (d) Only the better candidates achieved full marks, with the majority gaining two. Very few linked the high numbers of mitochondria with a high rate of respiration. The most common omission was a failure to link an adaptation with the function of these cells in absorption. E2. Cell structure was generally well understood, although some candidates assumed that cell walls are a feature of eukaryotic cells and are absent from prokaryotes. The calculation was attempted by the majority of candidates, most of whom measured the scale bar and gained at least one mark. E3. (a) There were many good responses here. Most candidates could identify these organelles, although a surprising number of candidates left the answer blank. (b) In (i), many candidates explained the differences in shape by suggesting that the drawing had been done badly, or that the person doing the drawing had not observed the cell section clearly enough. However, a significant minority correctly understood that the section could have cut the organelles in different planes. In (ii), most candidates who recognised the organelles could give an acceptable answer. A few failed to obtain marks due to careless expression; such as suggesting that X ‘produces energy’, or by a simplistic answer such as ‘they produce mucus’. A few thought that Z (the Golgi body) was involved in protein synthesis.
Eukaryotic-Cells-Exam-Qs.docx