3.19b F1 x F1 Cross

3.19a P1 x P1 Cross

3.18b Genotypes

3.18a Phenotypes

3.2 Fertilisation

• The adult male and female gametes are formed by meiosis. 
• When we have sufficient cells this will then be called an embryo.
• The cells that are formed by meiosis have half as many chromosomes as the cell that formed them.
• Fertilisation occurs when a male and female gamete join.
• The zygote divides into a ball of cells, called the blastula which then grows to form the embryo.

3.9a Male reproduction system

• Urine is stored in the bladder.
• The penis carries the sperm into the vagina.
• Sperm is stored in the epididymis.
• The seminal vesticle produces 70% of the semen.
• Urethra is the tube which connects the testes and the SV which takes semen to the penis.

3.12 Amniotic Fluid

• Amniotic fluid is found inside the embryo.
• If anything happens to the outside uterus amniotic fluid prevent anything happening to the unborn child.
• Amniotic fluid can't be compressed, it absorbs pressure. 

3.11 Placenta

• The placenta grows out of the developing embryo not the mother. 
• The blood vessels inside the placenta are the child's blood vessels including arteries and veins.
• The placenta grows into the wall of the uterus. 
• Glucose, amino acids and fats travels through the mother's blood stream and into the wall of the uterus. 
• Glucose, amino acids and fats will cross into the child's blood at the placenta.
• Amino acids, sugars and fats will go from the mother's to the child's blood.