Reproductive Behaviour

Mammals are either able to breed year round, or in breeding seasons

Gametes are:

- male: small and motile, produced in large quantities

- female: large and less motile, few produced

Gametogenesis:

- male: sperm production = spermatogenesis

- female: egg formation = oogenesis

Female mammals have two cycles: oestrous cycle and menstruation cycle

Oestrous cycle: - ovulation, female is most fertile

Menstruation cycle:

- uterus lining thickens during reproduction cycle

- if fertilisation does not occur, lining breaks down menstruating mammals > discharged as blood through vagina

non-menstruating mammals > reabsorbed, no bleeding

Discharge of blood = menstruation

Menstrual Cycle: - controlled by hormones over duration of approx. 28 days

- 3 main phases: follicular, ovulatory, luteal

Follicular: 1st part of menstrual cycle; follicles start to develop into mature female gamete. Follicle cells surround developing egg cell and produce hormones that trigger other responses

Ovulatory: oocyte is released from ovary and passes down fallopian tube into uterus

Luteal: most follicle cells remain after ovulation and continue to develop and form a structure, corpus luteum > more hormones are released

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