BIO co4.1

• Reproduction

  biological process by which new individuals of the same species are produced, ensuring the continuation and survival of that species.
• Mode of reproduction

  Asexual and sexual reproduction
• Asexual reproduction

  • A single parent produces offspring without the involvement of gametes or fertilization.
  • The offspring is genetically identical or nearly identical to the parent, as there is no genetic recombination.
• Sexual reproduction

  • Two parents contribute genetic material to produce offspring.
  • Specialized cells called gametes, which are produced by the reproductive organs, combine to form a new organism.
  • The offspring inherits a combination of genetic material from both parents, resulting in genetic diversity.
• Sporophyte Generation

  • Diploid (2n)
• Gametophyte Generation

  • Haploid (n)
  • Microspore = Male gametophyte
  • Megaspore = Female gametophyte
• Complete Flower structure

  • sepals
  • petals
  • stamens
  • carpels
• Stamen = male portions of flower

  Carpel = vaselike structure that represents the female portion of the flower.

  petal = accounts for the attractiveness

  sepal = leaflike of all the flower parts are usually green.

  receptacle = vaselike structure that represents the female portion of the flower.
• Asexual Reproduction

  Vegatative Propogation

  • involves the generation of new individuals without the involvement of seeds
  • is a process in which plants reproduce from stems, roots and leaves
• Animal Reproductive Strategies

  Most animals reproduce sexually

  • Requires meiosis to produce haploid Gametes (sperm and eggs)
  • Gametes united by fertilization to produce the diploid zygote
  • zygote develops by mitosis into a new multicellular organism.
• Animals usually produce gametes in specialized organs termed gonads.

  • testes produce sperm
  • ovaries produce eggs.

  Eggs and sperm are derived from separate germ cells which specialize during development.

  Parthenogenesis

  • Modification of sexual reproduction.
  • Unfertilized egg develops into a complete individual.
• Most animals are dioecious.

  • separate sexes
  • egg of one parent is fertilized by sperm of another.

  Some animals are monoecious (hermaphroditic)

  • contain both male and female sex organs in a single body
  • majority practice cross-fertilization with other individuals. (example: Earthworms)
• External fertilization

  • gametes are released and unite outside the bodies of reproducing animals.
• Internal Fertilization

  • gametes unite inside the bodies of reproducing animals.
  • Copulation - sexual union to facilitate the reception of sperm, resulting in internal fertilization.
• Development strategies

  • internal fertilization has led to three strategies for development

  1. oviparity - fertilized eggs are deposited outside the mother's body to complete their development
  2. Ovoviviparity - fertilized eggs are kept within mother to complete development, young obtain food from egg yolk
  3. Viviparity - young develop within mother and obtain nourishment from her blood.
• Budding

  • Formation of a new individual as an outgrowth or "bud" on the parent organism.
  • Once developed, the bud detaches and becomes an independent organism.
• Fragmentation

  • Some animals can regenerate from fragments of their bodies. Each fragment has the potential to develop into a complete organism.