BIOLOGY Foundation Tier Paper 2F

GCSE BIOLOGY Foundation Tier Paper 2F Time allowed: 1 hour 45 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 100. • 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. *JUN22 4612F01* IB/M/Jun22/E16 8461/2F Answer all questions in the spaces provided. outside the box Maple syrup urine disease (MSUD) is a rare inherited human condition. The allele for MSUD is recessive. . What is a recessive allele? Tick () one box. [1 mark] An allele expressed only if a person has two copies of the allele An allele expressed only if it is inherited from the male parent An allele expressed when it is found on only one of the chromosomes Figure 1 shows the inheritance of MSUD in one family. Figure 1 . The symbol is not in the key for Figure 1. What would this symbol represent? [1 mark] Persons 1 and 2 in Figure 1 have a child with MSUD and some children without MSUD. box . Complete Figure 2 to show the possible genotypes of the children. Use the following symbols: N = allele for not having MSUD n = allele for MSUD [2 marks] Figure 2 Person 2 Person 1 . What is the phenotype of a person with the genotype Nn? [1 mark]