1.4 Step 1: Identify the process at I. 1.4.1 Fertilisation Step 2: State the type of cell division at II. 1.4.2 Mitosis Step 3: Name two extra-embryonic membranes produced by structure C (blastocyst). 1.4.3 Amnion and Chorion Step 4: Identify the stages of development. 1.4.4 (a) Ovum 1.4.4 (b) Morula 1.4.4 (c) Blastocyst Step 5: Name the part of the female reproductive system where these events occur. 1.4.5 Fallopian tube (or Oviduct) Step 6: Determine the chromosome number for a cell at A (ovum) leading to Down Syndrome. Down Syndrome is Trisomy 21, meaning an extra chromosome 21. A normal ovum has 23 chromosomes. An ovum leading to Down Syndrome would have an extra chromosome 21. 1.4.6 24 2.4 Step 1: Identify the labelled parts of the diagram. 2.4.1 (a) Uterus (or Uterine wall) 2.4.1 (b) Umbilical cord 2.4.1 (c) Placenta Step 2: State two functions of the fluid in part B (amniotic fluid). 2.4.2 Protects the foetus from mechanical shock/injury. Maintains a constant temperature for the foetus. Step 3: Name one system in the baby's body that takes over the function of part D (placenta) after birth. The placenta is responsible for gas exchange, nutrient supply, and waste removal. 2.4.3 Respiratory system (for gas exchange) Step 4: Explain one negative impact on foetal development if part D (placenta) is significantly reduced. 2.4.4 A significantly reduced placenta would lead to insufficient transfer of oxygen and nutrients to the foetus, resulting in poor growth and development (e.g., intrauterine growth restriction). That's 2 down. 3 left today — send the next one.