Asexual vs Sexual Reproduction

• Asexual reproduction involves a single parent and no gametes.
• In asexual reproduction, the parent passes its genes to the offspring.
• The offspring in asexual reproduction is genetically identical to the parent, essentially a clone.
• Sexual reproduction involves two parents, each donating one gamete.
• In sexual reproduction, both parents pass on one of each gene to the offspring.
• The offspring in sexual reproduction has a unique genetic identity.

Types of Asexual Reproduction

• Asexual reproduction includes fission, fragmentation, and budding.
• Fission occurs in bacteria, where chromosomes duplicate, segregate, and cytokinesis follows.
• Fragmentation involves a part of the body breaking off and regenerating into a whole organism.
• Budding is when a bud forms and grows into a new individual.

Sexual Reproduction Details

• Gametes are produced by meiosis in sexual reproduction.
• Sperm (n) unites with egg (n) to form a zygote (2n).
• Fertilization is the union of a haploid male gamete with a haploid female gamete to form a diploid zygote.
• Male and female gametes can be produced by separate individuals, as in humans, or by the same individual, hermaphrodites.
• Hermaphrodites can self-fertilize or cross-fertilize.
• Fertilization can occur inside the female (internal) or outside the body (external).
• Hermaphrodites like tapeworms can self-fertilize.
• Other hermaphrodites can cross-fertilize by exchanging sperm.
• External fertilization occurs outside the body.
• Internal fertilization occurs inside the body.

Anatomy of the Female Reproductive System

• Eggs are produced by follicles in the ovaries.
• Fertilization occurs in the fallopian tubes, not the uterus.
• The female system includes urinary, reproductive, and digestive systems.

Anatomy of the Male Reproductive System

• Sperm is kept at 98.69 degrees Fahrenheit in the epididymis.
• The seminal vesicle produces a fructose-like liquid.
• The prostate gland produces a milky white alkaline secretion to neutralize the vaginal pH.
• The male reproductive system has an intromittent organ.
• The male system combines urinary and reproductive functions into one.
• In males, the urinary and reproductive systems do not work simultaneously; simultaneous activity indicates a malfunction.

Gametogenesis

• Gametogenesis is the formation of gametes.
• Spermatogenesis is the formation of sperm.
• Oogenesis is the formation of ova (eggs).

Spermatogenesis Details

• Spermatogenesis starts around age 12 or 13.
• It takes 74 days to complete spermatogenesis, starting with about 3 million sperm.

Oogenesis Details

• Oogenesis starts at 5 months in the mother's uterus.
• Eggs in the ovaries are kept at prophase I of meiosis from birth until age 13 or 14.
• Eggs are kept in metaphase II of meiosis II in the uterus until fertilization.
• By puberty, a girl has about 400,000 eggs left in her ovaries.