Lesson 5 Planting

• Plant is a living organism that produces food for themselves and acts as the primary source of nutrition for all life forms on earth. Plants are also the only source of oxygen in nature.
• Plants form the most vital and most essential components of our environment.
• Our precious soil also needs plants.
• Plants also help to slow erosion
• Roots


  The part that lies below the surface of the soil. The top part of a root (root apex) is covered by a covering known as root cap.
• Functions of roots


  • Absorbing water and minerals from the soil
  • Storing food for future use
  • Producing plant growth hormones
  • Anchoring the plant firmly to the soil and providing support
• Tap root system


  The primary roots and its branches
• Fibrous root system


  Roots that originate from the base of the stem
• Adventitious roots


  Roots that arise from parts of the plant other than the radicle, found in plants like grass, Monstera and the banyan tree
• Types of adventitious roots

  • Prop roots
  • Stilt roots
  • Pneumatophores
• Stem


  Found above the ground, structurally divided into nodes and internodes. The regions where leaves are found are known as nodes, whereas the areas in-between the nodes are called internodes.
• Functions of stems


  • Providing strength and support to buds, flowers, leaves, and fruits
  • Storing food mainly in the form of starch
  • Transporting food, water, and minerals to all parts of the plant body
  • Vegetative propagation and protection under different conditions
• Underground stems


  • potato, ginger, turmeric, zaminkand, colocasia
• Stem tendrils


  Slender and spirally coiled, develop from axillary buds and help plants to climb
• Axillary buds


  May get modified into woody, straight and pointed thorns
• Leaves


  A fundamental part of a plant, found above the ground and attached to the stem. A leaf consists of three main parts: i) the petiole, ii) leaf base, and iii) lamina or leaf blade.
• Functions of leaves


  • Making food for the plant with the help of sunlight, carbon dioxide, and water through photosynthesis
  • Helping in reproduction such as in Bryophyllum, a group of sprout leaf plants
  • Helping in evaporation from the aerial parts of the plant by transpiration
  • Modification to form tendrils, spines, or fleshy storage
• Flower


  The most colorful and attractive parts of a plant, known as the reproductive products of plants. A flower contains four main parts: a) Sepals b) Petalsc) Stamens d) Carpel
• Fruit


  The products of reproduction in plants, containing the essential component for reproduction - the seed
• Functions of flowers


  • Helping in the sexual reproduction of plants
  • Stimulating pollination in plants and fertilization of the ovule
• Seed


  Contains plant material that can develop into another plant, called an embryo. Seeds are covered with a protective seed coat and have one or two cotyledons, which are the food for the baby plant until it can make its own food from light and are often the first embryonic leaves of the plant.
• Indeterminate growth


  Characteristic of plant parts like stems and roots, which continue to grow throughout a plant's life
• Determinate growth


  Characteristic of plant parts like leaves and flowers, which ceases when a plant part reaches a particular size
• What helps plants grow

  • Water
  • Air
  • Sunlight
  • Soil
• Soil


  Provides plants with the foothold for their roots, holds necessary nutrients, filters rainwater, and regulates excess rainwater
• Sunlight


  Key energy source for plants, fuels the process of photosynthesis
• Air


  Needed for photosynthesis and respiration
• Water


  Essential for germination, growth of roots, and nutrition and multiplication of soil organisms
• Stages of plant growth

  • Primary growth
  • Secondary growth
• Primary growth


  Increase in length of the shoot and the root, due to cell division in the shoot apical meristem
• Secondary growth


  Increase in stem thickness, due to the activity of the lateral meristems
• Plant hormones


  Chemical messengers that affect all aspects of plant life, produced in potentially every cell and acting synergistically or antagonistically
• Major plant hormones


  • Auxins
  • Cytokinins
  • Gibberellins
  • Ethylene
  • Abscisic acid
• Auxins


  Main hormones responsible for cell elongation in phototropism and gravitropism, control differentiation of meristem, and promote leaf development and arrangement
• Cytokinins


  Promote cytokinesis (cell division), most abundant in growing tissues
• Gibberellins


  Regulate a wide range of processes involved in plant growth, organ development, and environmental responses
• Abscisic acid


  Signals dehydration and makes leaves close their stomata to prevent water loss
• Ethylene


  Associated with fruit ripening, flower wilting, and leaf fall, a volatile gas
• Other compounds influencing plant development

  • Jasmonates
  • Oligosaccharins
• Seed germination


  The process by which a plant grows from a seed into a seedling developing into a new plant