Bio

• Reproduction


  The process by which organisms produce offspring, allowing the propagation and continuation of species
• Types of reproduction


  • Sexual reproduction
  • Asexual reproduction
• Sexual reproduction


  • Involves the formation of offspring by the fusion of gametes
• Asexual reproduction


  • Involves the formation of offspring without the fusion of gametes
• Types of plants


  • Nonvascular plants
  • Vascular plants
• Plant life cycle

  1. Diploid phase (zygote divides by mitosis to form sporophyte)

  2. Sporophyte produces haploid spores by meiosis

  3. Haploid spore divides by mitosis to form gametophyte

  4. Gametophyte produces gametes (sperm and egg) by mitosis

  5. Fertilization of sperm and egg forms new zygote
• Alternation of generations


  The life cycle that alternates between diploid and haploid phases
• Bryophytes (mosses and liverworts)


  • Haploid gametophyte is the dominant generation
• Tracheophytes (vascular plants)


  • Diploid sporophyte is the dominant generation
• Nonvascular plants


  • Simple plants without a conducting system for food and water
  • Include mosses, liverworts, and hornworts
• Moss life cycle


  1. Spore germinates to form gametophyte

  2. Gametophyte produces male and female structures

  3. Sperm fertilizes egg to form sporophyte

  4. Sporophyte produces spores
• Vascular plants


  • Have xylem and phloem to transport water and food
  • Include seedless vascular plants like club mosses, horsetails, and ferns
• Fern life cycle


  1. Spore germinates to form prothallus (gametophyte)

  2. Prothallus produces sperm and egg

  3. Sperm fertilizes egg to form zygote

  4. Zygote grows into mature sporophyte (fern plant)

  5. Sporophyte produces spores
• Types of seed plants

  • Gymnosperms
  • Angiosperms
• Seed


  A small embryonic plant enclosed in a seed coat, usually with stored food
• Types of seeds


  • Monocot
  • Dicot
• Monocot seeds


  • Have one cotyledon, endosperm not inside cotyledon (e.g. corn)
• Dicot seeds


  • Have two cotyledons, endosperm inside cotyledons (e.g. peanut)
• Parts of a seed embryo

  • Plumule (forms leaves)
  • Hypocotyl (forms stem)
  • Radicle (forms root)
• Gymnosperms


  Seed-producing plants with naked seeds that develop on surfaces of leaves or scales, forming cones
• Angiosperms


  Flowering plants that produce seeds enclosed in fruits
• Parts of a flower

  • Sepals
  • Petals
  • Stamens
  • Carpel
  • Pistil
  • Stigma
  • Style
  • Ovary
• Diploid sporophyte


  • The dominant generation in flowering plants that bears flowers
• Double fertilization


  One sperm cell fertilizes the egg, the other fuses with the polar nuclei to form the endosperm
• Types of fruits


  • Fleshy fruits (drupes, berries, pomes, hesperdia, pepos)
  • Dry fruits (follicles, legumes, capsules, achenes, nuts, samaras, schizocarps, caryopses)
• Types of asexual reproduction in animals

  • Budding
  • Gemmation
  • Fragmentation
  • Regeneration
• Types of sexual reproduction in animals

  • External fertilization
  • Internal fertilization (oviparity, ovoviviparity, viviparity)
• External fertilization


  • Sperm and eggs are released into the external environment, usually water
• Internal fertilization


  • Sperm fertilizes egg within the female
• Oviparity


  • Fertilized eggs develop and hatch outside the mother's body
• Ovoviviparity


  • Eggs develop and hatch within the mother's body, offspring nourished by unfertilized eggs
• Viviparity


  • Young develop within the female and are nourished directly from the mother through a placenta