• Asexual reproduction allows an organism to rapidly produce many offspring without the time and resources committed to courtship, finding a mate, and mating.
  • The hydra produces buds; starfish can regenerate an entire body from a fragment of the original body. 

Sexual Reproduction

  • In sexual reproduction new individuals are produced by the fusion of haploid gametes to form a diploid zygote.
  • Sperm are male gametes, ova (ovum singular) are female gametes.
  • Meiosis produces cells that are genetically distinct from each other.
  • Fertilization is the fusion of two such distinctive cells.

Human Reproduction and Development

  • Gonads are sex organs that produce gametes. Male gonads are the testes, which produce sperm and male sex hormones. Female gonads are the ovaries, which produce eggs (ova) and female sex hormones.

The Male Reproductive System

  • Sperm production begins at puberty and continues throughout life, with several hundred million sperm being produced each day. Once sperm form they move into the epididymis, where they mature and are stored.

External Genitals

  • The female external genitals are collectively known as the vulva.

Sexually Transmitted Diseases

STDs can affect the sex partners, fetus, and newborn infants. STDs are grouped into three categories.

Category One

STDs that produce inflammation of the urethra, epididymis, cervix, or oviducts. Gonorrhea and chlamydia are the most common STDs in this category. Both diseases can be treated and cured with antibiotics, once diagnosed.

Category Two

STDs that produce sores on the external genitals. Genital herpes is the most common disease in this class. Symptoms of herpes can be treated by antiviral drugs, but the infection cannot be cured. Syphilis is a bacterially caused infection, and can, if left untreated, cause serious symptoms and death. However, the disease is curable with antibiotics.

Category Three

This class of STDs includes viral diseases that affect organ systems other than those of the reproductive system. AIDS and hepatitis B are in this category. Both can be spread by sexual contact or blood. Infectious individuals may appear symptom-free for years after infection.

The separation of intercourse from pregnancy uses methods blocking one of the three stages of reproduction

  • release and transport of gametes
  • fertilization
  • implantation


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