Identify and explain the functions of parts of the male and female reproductive systems, and the impact of external factors on reproduction.

• 1.5.1 (a) A: Head (of sperm)
• 1.5.1 (b) B: Midpiece (of sperm)
• 1.5.1 (c) C: Tail (of sperm)
• 1.5.1 (d) F: Acrosome

• 1.5.2 (a) Contains the mitochondria: B (Midpiece)
• 1.5.2 (b) Contains enzymes required to penetrate the ovum: F (Acrosome)
• 1.5.2 (c) Will enter the ovum during fertilisation: A (Head)

• 2.1.1 A: Urethra

Semen is composed of sperm and seminal fluid. Seminal fluid is produced by the seminal vesicles, prostate gland, and bulbourethral glands.

• 2.1.2 B and F (or B and G, or F and G)

• 2.1.3 Tight-fitting underwear increases the temperature of the testes. The testes need to be at a temperature slightly lower than body temperature for optimal sperm production (spermatogenesis). An increased temperature will inhibit or reduce sperm production, leading to a lower sperm count or abnormal sperm, which can result in reduced fertility or infertility.