Gen Bio Reproduction

• Sexual Reproduction in Plants: Fertilization

  • The male part of the flowering plant is the stamen, composed of the anther which produces pollen and the filament which supports the anther
  • The female part of the flowering plant is the carpel, made up of the stigma which traps the pollen, the style and the ovary which produces the ovules

  
• Sexual Reproduction in Plants: Fertilization

  1. Pollen grains from another/same flower lands on the stigma through pollination

  2. Pollen gets slipped into the ovary through a pollen tube and enters the ovule where it combines with female eggs to form a fertilized cell called a zygote

  3. This process of fusion of gametes to form zygote is called fertilization

  
• Plant Reproductive Organs

  • The anthers are inside the plant which protects the pollen from being lost by wind

  
• Carpel


  The female part of the flowering plant

  
• Pistil

  The female part of the flowering plant

  
• Insect pollination


  • Petals are brightly colored
  • Flowering plants emit strong scents as chemical signals to attract insects
  • Flowering plants produce nectar as a food source for insects

  
• Wind pollination


  • Pollen grains are carried through the air by wind movement
  • The stigma is outside the flower structure and has a large surface area to maximize pollen collection
  • Pollen grains are produced in large quantities to maximize successful pollination

  
• Formation of Fruit and Seed

  1. After fertilization, the zygote develops into an embryo, the ovule changes into a seed and the ovary turns into a fruit

  2. The rest of the flower parts dry up and fall away

  3. Under favorable conditions the seeds grow and develop into new plants

  
• Seed Coat


  Thick outer covering that protects seeds and prevents drying out
• Cotyledons


  Seed leaves that cover and store food for the baby plant

  
• Embryo


  Tiny baby plant inside the seed
• Embryonic axis


  Consists of the hypocotyl, radicle, and plumule
• Hypocotyl


  Portion of the embryo between the cotyledon attachment point and the radicle
• Radicle


  Embryonic root, the region from which the root will develop
• Epicotyl


  Part of the embryonic axis that projects above the cotyledons
• Plumule


  Composed of the epicotyl, young leaves, and the shoot apical meristem
• Germination of Seed


  1. Seed gets enough light, air, water, and warmth

  2. Seedling uses food stored inside the seed for growth

  3. Young plant develops roots and shoots, tiny leaves start making food

  
• Germination


  The process by which a seed grows into a young plant or seedling
• Many plants grow from seeds, which are the reproductive part of a plant

  
• Seed Dispersal


  1. Seeds can be dispersed to nearby or far places through different agents

  2. The process by which seeds are moved away from the parent plant is called seed dispersal
• Asexual Reproduction in Plants

  Baby plants are produced from a single parent without involvement of gametes
• Vegetative Propagation Methods

  • Propagation by Stem
  • Propagation by Roots
  • Propagation by Leaves
• Vegetative Propagation by Stem


  New plants arise from the nodes where buds are formed, which grow into new plants

  
• Vegetative Propagation by Stem

  • Potato tuber
  • Onion bulb
  • Ginger rhizome
• Vegetative Propagation by Roots


  Roots develop adventitious buds that grow into leafy shoots under favorable conditions

  
• Vegetative Propagation by Roots

  • Sweet potato
  • Turnip
  • Garlic
  • Water hyacinth
  • Lily
• Vegetative Propagation by Leaves


  Buds originate from the leaf margins when they come in contact with soil, and the new plant can be separated

  
• Vegetative Propagation by Leaves

  • Bryophyllum

  
• Principal Methods of Artificial Vegetative Propagation

  • Cuttings
  • Layering
  • Grafting
  • Budding
  • Suckers
• Cuttings


  Portions of plants which are cut and used for multiplying the plant, such as stem, leaf or root
• Plants propagated by Cuttings

  • Sweet potatoes
  • Cassava
  • Bougainvillea
  • Hibiscus
• Layering


  Stems of the plant are covered with soil until new roots originate, then the plant is separated from the mother plant
• Plants propagated by Layering

  • Strawberry
• Budding


  A cutting of a healthy mature plant is taken and planted in soil for root and shoot development
• Plants propagated by Budding

  • Rose
  • Dahlia
  • Gardenia
• Grafting


  The plant with the shoot system (scion) is attached to the plant with the root system (stock) to obtain characteristics of both parent plants
• Plants propagated by Grafting

  • Mango
  • Cherry
  • Apple
• Suckers


  Special shoots produced by some plants that are divided from the parent and transplanted to grow into a new plant
• Plants that produce Suckers

  • Banana
• Fragmentation


  The parent organism divides into several fragments that then grow and mature into new individuals