Nutrition in Plants

Start music   Jan 11 2017 || 12:45 PM

  • Nutrients – Components such as carbohydrates, proteins, fats, vitamins and minerals

 

  • Nutrition – It is the mode of taking food by an organism and its utilisation by the body

 

  • Modes of nutrition – There are 2 modes of nutrition:
    1. Autotrophic – Where organism prepares its own food. Plants are autotrophs.
    2. Heterotrophic – Where organism takes in the readymade food prepared by the plants. These organisms are called heterotrophs

 

Cells

  • Living organisms are made up of tiny units called cells
  • The cell is enclosed by a thin outer boundary, called the cell membrane
  • Cells generally have a distinct, centrally located spherical structure called the nucleus
  • The nucleus is surrounded by a jelly-like substance called cytoplasm

 

Photosynthesis

  • The process by which plants prepare food from air & water in the presence of sunlight
  • Plants use Carbon dioxide, water and sunlight to prepare carbohydrates.
  • O2 is produced during photosynthesis and carbohydrates get converted to starch

 

Significance of various parts in photosynthesis

  • Leaves – Where food preparation in plants occur
  • Stomata - tiny pores present on the surface of the leaves which help the plant to breathe. They are surrounded by guard cells
  • Chlorophyll – The green pigment of the leaves. They help in capturing the energy of the sunlight
  • Roots – Where water and minerals are absorbed by the plants

 

Synthesis of proteins by plants

  • Soil has certain bacteria that convert gaseous nitrogen into a usable form and release it into the soil
  • These soluble forms are absorbed by the plants along with water
  • In this way the plants fulfil their requirements of nitrogen and synthesis components other than carbohydrates

 

 

Other Modes of Nutrition in Plants

Parasitic mode

  • A plant called Cuscuta (Amarbel) does not have chlorophyll
  • It takes readymade food from the host plant on which it is climbing

 

Insectivores’ plants

  • The pitcher plant’s leaf is modified into the form of a pitcher
  • The apex of the leaf forms a lid which can open and close the mouth of the pitcher
  • Inside the pitcher there are hairs which are directed downwards
  • When an insect lands in the pitcher, the lid closes & it gets entangled in the hair
  • The insect is then digested by the digestive juices secreted inside the pitcher

 

Saprotrophic nutrition

  • Where organisms take in nutrients in from the dead and decaying matter (eg: fungi)
  • They secrete digestive juices on the decaying matter, and convert it into a solution.
  • Then they absorb the nutrients from the solution
  • Such organisms are called saprotrophs.

 

Symbiotic relationships

  • Lichens – Where a chlorophyll containing alga and fungus live together to benefit from each other
  • Certain fungi live in the roots of trees. The tree provides nutrients to the fungus and, in return, receives help from it to take up water and nutrients from the soil
  • The bacterium called Rhizobium can convert atmospheric nitrogen into a soluble form. But since it cannot make its own food, it lives in the roots of leguminous plants and provides them with nitrogen in exchange for food

 

Replenishment of nutrients from soil

  • Fertilisers and manures contain plant nutrients such as nitrogen, potassium, phosphorous, etc should be added from time to time