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• Contraceptives


  Methods or devices used to prevent pregnancy
• Types of contraceptives


  • Hormonal contraceptives
  • Barrier methods
  • Intrauterine devices (IUDs)
  • Sterilization
  • Natural family planning
• Hormonal contraceptives


  • Contain hormones (progestin and/or estrogen) that prevent ovulation, thin the lining of the uterus, and thicken cervical mucus to prevent sperm from reaching the egg
  • Highly effective when used correctly, but may have side effects such as headaches, nausea, and weight gain
• Barrier methods


  • Physically block sperm from entering the uterus
  • Inexpensive and easy to obtain but may be less effective than hormonal methods and require consistent and correct use to be effective
• Intrauterine devices (IUDs)


  • Small, T-shaped devices inserted into the uterus
  • Can be hormonal (releasing progestin) or nonhormonal (made of copper)
  • Prevent sperm from reaching the egg and thin the lining of the uterus
  • Highly effective and long-lasting (up to 10 years for some types) but may cause side effects such as cramping and irregular bleeding
• Sterilization


  • Permanent form of contraception involving surgical procedures such as tubal ligation (for women) or vasectomy (for men)
  • Highly effective but considered irreversible and should be carefully considered as a long-term option
• Natural family planning


  • Involves tracking the menstrual cycle to determine when ovulation occurs and abstaining from sex during fertile periods
  • Requires careful monitoring and may be less effective than other methods
• Asexual reproduction


  Requires only one organism, offspring are genetically identical, usually faster and simpler than sexual reproduction
• Types of asexual reproduction


  • Binary fission
  • Budding
  • Fragmentation
  • Parthenogenesis
• Sexual reproduction


  Requires two gametes (sperm cell and egg cell), each containing 23 chromosomes which combine into a zygote with 46 chromosomes, offspring are genetically diverse
• Meiosis

  Gamete production process
• Common terms in sexual reproduction

  • Hermaphroditism
  • Monoecy and dioecy
  • Sequential hermaphroditism
  • Mating systems (monogamy, polygyny, polyandry)
• Human sexual reproduction


  1. Ovulation - production of matured egg

  2. Ejaculation of sperm - entering of sperm

  3. Fertilization - sperm meets egg

  4. Development - zygote grows and develops
• Development of human zygote

  1. Day 1: Zygote - combination of sperm and egg in the fallopian tube

  2. Day 2-3: Cleavage - cells divide, increasing in number but not increasing in size

  3. Day 4: Morula (16 cells)

  4. Day 5: Blastocyst (32+ cells)

  5. Day 7: Shedding of the Zona Pellucida and Implantation of the Blastocyst in the Uterus
• If fertilization does not occur, the egg will leave the uterus along with the shedding of the lining
• Plant sexual reproduction (pollination)

  1. Flowering plants contain male sex organs (stamen) and female sex organs (pistil)

  2. Self-pollination - a plant's own pollen fertilizes its own ovules

  3. Cross-pollination - wind or animals move pollen from one plant to fertilize the ovules on a different plant
• Types of animal fertilization

  • Internal fertilization
  • Oviparity
  • Ovoviparity
  • Viviparity
  • External fertilization
• Hypothalamus


  Produces GnRH (Gonadotropin-releasing hormone), regulates the pituitary gland by producing releasing hormones
• Pituitary gland


  Releases the hormones FSH and LH
• Follicular phase


  1. Pituitary produces FSH (Follicle Stimulating Hormone), which stimulates the egg production

  2. Follicle growth

  3. Estrogen release
• Ovulation


  Pituitary releases LH (Luteinizing Hormone) on the 14th day causing ovulation
• Luteal phase


  Fully mature egg cell bursts from the follicle, empty follicle transforms into the corpus luteum, egg travels through fallopian tube, if not fertilized the corpus luteum shrinks triggering menstruation and ripening of new egg
• Menstruation


  Endometrium lining sheds along with the blood and tissue through the vagina
• Male reproductive organs in plants (stamens)


  • Each stamen consists of a filament and an anther
  • Anther is responsible for the production of pollen
  • Filament holds the anther and attaches it to the flower
• Female reproductive organs in plants (pistils)

  • Each pistil consists of an ovary, a style, and a stigma
  • Ovary contains one or more ovules, which contain the female gametes (egg cells)
  • Style connects the ovary to the stigma, which receives the pollen
• Ways plants can reproduce

  • Sexual reproduction
  • Asexual reproduction (vegetative propagation, apomixis, fragmentation)
  • Combination of sexual and asexual reproduction
• •Binary Fission – Parent organism divides into two identical daughter cells. Bacteria and many single-celled Eukaryotes multiply by splitting into two.
• •Budding – A new individual develops as an outgrowth or bud from the parent organism. A Hydra reproduce by budding an identical offspring off of themselves.
• •Fragmentation -Tthe parent organism breaks into multiple pieces, each of which can grow into a new individual. Commonly observed in some plants and animals.
• •Parthenogenesis - An egg develops into a new individual without being fertilized by sperm. Observed in some invertebrates, fish, reptiles, and birds.
• Hermaphroditism – Organisms can sometimes have both male and female reproductive organs and can produce both eggs and sperm. This is common in many invertebrates, such as snails and earthworms.
• Monoecy and Dioecy – Monoecy is the presence of both male and female reproductive organs on the same plant. Dioecy is the presence of male and female reproductive organs on separate plants.
• Sequential Hermaphroditism – Some organisms change their sex during their lifetime.
• Monogamy – One male mates with one female.

  Polygyny – One male mates with multiple females.

  Polyandry – One female mates with multiple male.
• 1.Once a month, a matured egg cell is released by the ovaries. Once released, the egg cell only lasts for 12-24 hrs before it dissolves and sheds with the euterine lining.
• 1.Sperm is ejaculated into the vagina. It passes through the cervix and uterus. It is in the fallopian tube where the sperm meets the egg, where fertilization will occur. A sperm cell can last for 5 days inside a woman’s body. This is why a female is fertile for 5-6 days days every menstrual cycle.
• Aside from the typical sexual reproduction that requires a male and a female, there are some Hermaphroditic creatures, meaning they posses both male and female reproductive organs just like plants. Some switch sexes, some are born with both.
• Oviparity – Fertilized egg forms a hard shell with the yolk and the developing offspring inside. The eggs develop and hatches. Usually occurs with birds, most reptiles and fish.
• Viviparity – The fertilized egg does not form a hardshell and yolk. The offspring receives nourishment through the placenta. Occurs with mos mammals.
• Ovoviparity – Same with Oviparity, but the female keeps the egg inside her body. Occurs with some fish like tiger sharks, some amphibians like the Surinam toad, and some reptiles like vipers.