Bio-unit 2

• What type of gametes are produced from diploid germline stem cells?

  Haploid
• The interstitial cells of the testes produce the hormone testosterone
• Each ovum is surrounded by a follicle.
• What does the follicle surrounding the ovum secrete?

  Hormones
• Fertilisation occurs when a male and female nucleus fuse
• Hormones control the onset of puberty, sperm production, and the menstrual cycle.
• Steps in the hormonal influence of puberty

  1️⃣ The hypothalamus secretes a releaser hormone

  2️⃣ The pituitary gland is targeted

  3️⃣ FSH, LH, or ICSH is released

  4️⃣ Puberty begins
• Which hormone is released by the pituitary gland in women to control sperm production?

  ICSH
• What part of the testes does FSH target to stimulate sperm production?

  Seminiferous tubules
• Negative feedback control of testosterone by FSH and ICSH maintains stable hormone levels.
• High testosterone levels inhibit the secretion of FSH and ICSH
• The menstrual cycle begins with the first day of menstruation.
• What effect does oestrogen have on the endometrium during the follicular phase?

  Thickens it
• What event is triggered by peak levels of LH?

  Ovulation
• Progesterone is secreted by the corpus luteum during the luteal phase.
• High levels of oestrogen inhibit the production of FSH
• If fertilisation occurs, the corpus luteum does not degenerate and progesterone levels remain high.
• Why are males continuously fertile?

  Constant hormone levels
• Females are most likely to conceive during the fertile period around the time of ovulation
• Methods to identify the fertile period in females

  1️⃣ Count days after menstruation

  2️⃣ Monitor body temperature

  3️⃣ Observe cervical mucus
• What hormones do drugs used to stimulate ovulation mimic?

  FSH and LH
• Drugs can prevent the negative feedback effect of oestrogen on FSH secretion.
• Artificial insemination involves inserting sperm into the reproductive tract using a method other than sexual intercourse
• What is ICSI used to treat if mature sperm are defective?

  Fertilisation problems
• What two synthetic hormones are combined in the oral contraceptive pill?

  Oestrogen and progesterone
• Emergency hormonal contraceptive pills can prevent or delay ovulation