Fig. 3.1 shows a fetus developing in the uterus of a mother. The fluid labelled C contains cells from the fetus. A long, hollow needle may be used to withdraw some of the fluid into a syringe. The DNA from the cells in this fluid can then be analysed to find the sex of the fetus and to detect mutations. long-needled syringe used to remove some of fluid C fluid C uterus [Figure 3.1]

1. (a)Name fluid C and state its function. name of fluid function[2]
2. (b)(i)Label the placenta on Fig. 3.1 using a line and the letter P.[1]
3. (b)(ii)State two functions of the placenta. 1 2[2]
4. (c)Fig. 3.2 shows the chromosomes found in the nucleus of one cell of a developing fetus. [Figure 3.2 (karyotype with an extra chromosome on pair 21)] State the sex of this fetus and explain your answer. sex explanation[2]
5. (d)(i)This fetus has a mutation. Describe the mutation shown in Fig. 3.2.[2]
6. (d)(ii)Suggest the condition that this child could be born with as a result of this mutation.[1]

This question uses a diagram from the original paper, which isn't shown here. Open the full paper from the past papers archive to see it.