AQA_A Level Biology Paper 3_Question Paper 2022 | Practice Paper 3

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AQA A Level Biology Paper 3 Question Paper 2022 Practice Paper 3 - - - - - - 1 (a) What name is used for the non-coding sections of a gene? _________________________________________________... ____________ (1) Figure 1 shows a DNA base sequence. It also shows the effect of two mutations on this base sequence. Figure 2 shows DNA triplets that code for different amino acids. Figure 1 Original DNA base sequence A T T G G C G T G T C T Amino acid sequence Mutation 1 DNA base sequence A T T G G A G T G T C T Mutation 2 DNA base sequence A T T G G C C T G T C T Figure 2 DNA triplets Amino acid GGT, GGC, GGA, GGG Gly GTT, GTA, GTG, GTC Val ATC, ATT, ATA Ile TCC, TCT, TCA, TCG Ser CTC, CTT, CTA, CTG Leu (b) Complete Figure 1 to show the sequence of amino acids coded for by the original DNA base sequence. (1) A-LEVEL BIOLOGY Name: Practice Paper 3 Maximum marks: 78 Time Allowed: 2 hours These questions are from past papers covering topics and skills based on the advance information to help you prepare for the exams this summer. Answer all questions in the spaces provided. Section B will require lined paper This document is licensed to Haggerston School - MB260045Page 2 (c) Some gene mutations affect the amino acid sequence. Some mutations do not. Use the information from Figure 1 and Figure 2 to explain (i) whether mutation 1 affects the amino acid sequence __________________________________________________________ __________________________________________________________ __________________________________________________________ __________________________________________________________ (2) (ii) how mutation 2 could lead to the formation of a non-functional enzyme. __________________________________________________________ __________________________________________________________ __________________________________________________________ __________________________________________________________ (3) (d) Gene mutations occur spontaneously. (i) During which part of the cell cycle are gene mutations most likely to occur? __________________________________________________________ (1) (ii) Suggest an explanation for your answer. __________________________________________________________ __________________________________________________________ (1) (Total 9 marks) 2 A student investigated the stages of mitosis in a garlic root. The root tip was placed on a microscope slide with a stain. A cover slip was placed on top and the root tip was firmly squashed. (a) Explain why (i) a root tip was used; _______________________________ - - - [Show More]

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