Gen bio

• Reproduction


  The biological process by which "offspring" are produced from their "parents"
• Reproduction is a fundamental feature of all known life; each organism exists as the result of reproduction
• Types of reproduction


  • Sexual
  • Asexual
• Sexual reproduction


  Involves the fusion of male and female gametes to form a zygote. The fusion of the nuclei of male and female gametes is known as fertilization
• Sexual reproduction


  • Requires 2 parent organisms
  • Sperm + Egg fertilize one another to form a Zygote
• Asexual reproduction


  Does not involve gametes. The single organism makes a copy of itself and divides
• Asexual reproduction


  • Requires 1 parent organism
• Sexual reproduction


  Fusion of male and female gametes to form a zygote
• Fertilization


  Fusion of the nuclei of male and female gametes
• Asexual reproduction


  Parts of a mature organism may develop into new individuals without gametes
• Sexual reproduction


  Requires 2 parent organisms
• Asexual reproduction


  Requires 1 parent organism
• Sexual reproduction


  1. Sperm + Egg fertilize one another to form a Zygote

  2. The offspring are genetically unique from the parents, but contain a random combination of parental genes
• Asexual reproduction


  1. The single organism makes a copy of itself and divides

  2. The offspring are genetically identical to the parent
• Sexual reproduction used by

  • Humans
  • Other animals
  • Plants
• Asexual reproduction used by

  • Yeast
  • Sponges
  • Bacteria
• Pros of sexual reproduction

  • Produces genetically different babies, increasing the survival rate of the population
• Cons of sexual reproduction


  • Requires a lot of time and effort
• Pros of asexual reproduction

  • Extremely efficient
• Cons of asexual reproduction


  • If the parent has genetic defects/deficiencies, all of its offspring will also be 'weak'
• Plant reproduction


  • Use of bright colors to attract insects
  • Sex cells are transmitted by a vector (insect or bird)
• Animal reproduction


  • Males fighting for females (inclusive fitness)
  • Courtship pheromones and ultrasound are used by males in attracting female
  • Two sex cells, spermatozoa and oocyte meet during sexual intercourse
• Methods of reproduction


  • Asexual reproduction
  • Sexual reproduction
• Pollination


  The transfer of pollen from the anther to the stigma of the same flower or another flower
• Types of pollination


  • Self-pollination
  • Cross-pollination
• Self-pollination


  Pollen from another is deposited on the stigma of the same flower, or another flower on the same plant
• Cross-pollination


  Transfer of pollen from the anther of one flower to the stigma of another flower of the same species
• Unlike animals, plants do not have the ability to locomotion
• Agents of pollination


  • Birds
  • Insects
  • Wind
• Asexual reproduction in plants

  Plants can propagate even without the union of gametes
• Types of asexual reproduction in plants

  • Vegetative propagation
  • Apomixis
• Vegetative propagation


  Vegetative tissues (non-reproductive tissues) such as the stem, leaf, or root of the parent plant are used to reproduce new plants
• Binary fission


  Single parent cell divides into two daughter cells
• Organisms that undergo binary fission

  • Amoeba
  • Paramecium
  • Bacteria
• Budding


  Parent cell produces bud, it gets detached and develops into new individual
• Organisms that undergo budding

  • Yeast
  • Hydra
• Spore formation


  Reproduces by forming spores, under favourable conditions spores develop into new individuals
• Organisms that reproduce by spore formation

  • Fern
  • Fungi
  • Bacteria
• Fragmentation


  Organism with filamentous body breaks into two or more fragments, each fragment grows into a new individual
• Organisms that reproduce by fragmentation

  • Spirogyra