Fig. 3.1 presents a fetus developing inside a mother’s uterus. The fluid marked C has cells from the fetus in it. A long, hollow needle may be used to draw some of the fluid into a syringe. DNA taken from the cells in this fluid can then be examined to determine the fetus’s sex and to identify mutations.
(a)[2]
Name fluid C and state its role.
(b(i))[1]
Label the placenta on Fig. 3.1 by drawing a line and adding the letter P.
(b(ii))[2]
State two roles of the placenta.
(c)[2]
State the sex of this fetus and explain why.
(d(i))[2]
Describe the mutation that is shown in Fig. 3.2.
(d(ii))[1]
Suggest the condition that this child could be born with as a consequence of this mutation.
Worked solution & mark scheme
This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: “amniotic fluid” …