Biology > QUESTION PAPER (QP) > Pearson Edexcel Level 3 GCE (Biology B Advanced Subsidiary PAPER 1: Core Cellular Biology and Microb (All)

Pearson Edexcel Level 3 GCE (Biology B Advanced Subsidiary PAPER 1: Core Cellular Biology and Microbiology)

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Answer ALL questions. Some questions must be answered with a cross in a box . If you change your mind about an answer, put a line through the box and then mark your new answer with a cross . 1 A s ... tudent drew two types of white blood cell, from a slide viewed using a light microscope. X Y Cell A Cell B The student used the internet to research the actual diameter of these two types of cell. The student found several values for the diameters of cell A and cell B. They used the mean value for the diameter of cell B to calculate the magnification of the drawing of cell B. The student calculated the magnification of the drawing of cell B to be × 1571. The student found the following values for the diameter of cell A: 0.016mm, 0.022mm, 0.019mm, 0.021mm, 0.017mm. (a) Calculate the magnification of the drawing of cell A, using the mean diameter of this cell. Measure the diameter of cell A between the points X and Y on the diagram (b) This method of calculating the magnification of these drawings is not accurate. Describe a method that the student could use to calculate the magnification accurately. 2 Triglycerides, found in living organisms, have different melting points. Two factors that affect the melting point of a triglyceride are: 1. the length of the fatty acid chains 2. whether the fatty acid chains are saturated or unsaturated. (a) A triglyceride is made from the components glycerol and fatty acids. (i) How many of the following statements about triglycerides are correct? (1) • a glycerol molecule is joined to each fatty acid by an ester bond • an unsaturated fatty acid has at least one double bond between two carbon atoms • all triglycerides have three fatty acids joined to a glycerol A none B one C two D three (ii) The table shows the relative atomic mass of the elements present in a triglyceride.How much lower is the molecular mass of this triglyceride molecule, after it has been made from its components, compared with the sum of its component molecules? (1) A 18 B 33 C 54 D 99 [Show More]

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