AQA GCSE COMBINED SCIENCE: TRILOGY 8464/B/2H Biology Paper 2H Version: 1.0 Final *JUN238464B2H01* IB/M/Jun23/E7 8464/B/2H / QUESTION PAPER & MARKING SCHEME/ [MERGED] Marl( scheme June 2023

GCSE COMBINED SCIENCE: TRILOGY 8464/B/2H Biology Paper 2H Version: 1.0 Final *JUN238464B2H01* IB/M/Jun23/E7 8464/B/2H For Examiner’s Use Question Mark 1 2 3 4 5 6 TOTAL Friday 9 June 2023 Afternoon Time allowed: 1 hour 15 minutes Materials For this paper you must have: • a ruler • a scientific calculator. Instructions • Use black ink or black ball-point pen. • Pencil should only be used for drawing. • Fill in the boxes at the top of this page. • Answer all questions in the spaces provided. • If you need extra space for your answer(s), use the lined pages at the end of this book. Write the question number against your answer(s). • Do all rough work in this book. Cross through any work you do not want to be marked. • In all calculations, show clearly how you work out your answer. Information • The maximum mark for this paper is 70. • The marks for questions are shown in brackets. • You are expected to use a calculator where appropriate. • You are reminded of the need for good English and clear presentation in your answers. Please write clearly in block capitals. Centre number Candidate number Surname Forename(s) Candidate signature I declare this is my own work. GCSE COMBINED SCIENCE: TRILOGY Higher Tier Biology Paper 2H H 2 *02* IB/M/Jun23/8464/B/2H There are no questions printed on this page DO NOT WRITE ON THIS PAGE ANSWER IN THE SPACES PROVIDED Do not write outside the box 3 *03* Turn over ► IB/M/Jun23/8464/B/2H Do not write outside the 0 1 Sexual reproduction in humans involves the production of egg cells and sperm cells. box 0 1 . 1 Name the type of cell division that produces egg cells and sperm cells. [1 mark] 0 1 . 2 Sexual reproduction produces offspring that are genetically different from each other. Give two reasons why sexual reproduction causes variation in the offspring. [2 marks] 1 2 Question 1 continues on the next page 4 *04* IB/M/Jun23/8464/B/2H Do not write outside the Polydactyly is an inherited disorder. box The allele for polydactyly is dominant, D. A person with two copies of the allele d will not have polydactyly. 0 1 . 3 A person with the genotype DD is homozygous. What word describes the genotype Dd? [1 mark] 0 1 . 4 A person with the genotype Dd and a person with the genotype dd plan to have a child. Determine the probability that the child will have polydactyly. You should: • complete the Punnett square diagram • identify any offspring genotype that would have polydactyly. [5 marks] Probability that the child will have polydactyly = 5 *05* Turn over ► IB/M/Jun23/8464/B/2H Do not write outside the box 11 0 1 . 5 Embryos can be screened for the alleles that cause inheri