Vitamins

Vitamins are organic compounds which cannot be produced by the body and must be supplied in small amount in diet for the normal health, growth and maintenance of body.

Vitamins are essential to us for the normal and proper functioning of the body.  The absence or deficiency of a vitamin can cause specific diseases.

In 1912, Sir H G Hopkins first identified vitamins in milk. The name ‘vitamins’ was given by Casmir Funk.

Vitamins are classified into two types,

• Water soluble vitamins
• Fat soluble vitamins

Water soluble vitamins

Vitamin B complex and vitamin c are water soluble.

Fat soluble vitamins

Vitamins A, D, E and K  are fat soluble vitamins.

Sl.No.	Vitamins		Deficiency diseases
1	Vitamin B1	Thiamine (aneurin)	Beriberi
2	Vitamin B2	Riboflavin (lactoflavin)	Chillosis
3	Vitamin B3	Niacin	Pellagra
4	Vitamin B5	Pantothenic acid	Parasthesia
5	Vitamin B6	Pyridoxine	Dermites
6	Vitamin B7	Biotin	Seboria
7	Vitamin B9	Pholic acid	Megaloblastic anemia
8	Vitamin B12	Cyanocobalamin	Pernicias anemia
9	Vitamin C	Ascorbic acid	Scurvy
10	Vitamin A	Retinol	Nightblindness, xerophthalmia, xerosis
11	Vitamin D	Calciferol	Rickets
12	Vitamin E	Tocopherol	Sterility
13	Vitamin K	Phylloquinone	Bleeding

POLLINATION

Pollination is the mechanism to transfer  pollen grains from  the anther to the stigma of a pistil is termed pollination.


                                  

                               

KINDS OF POLLINATION

Depending on the source of pollen, pollination can be divided into three.

Autogamy            

Transfer of pollen grains from the anther to the stigma of same flower is called autogamy or self-pollination.

Geitonogamy  

    Transfer of pollen grains from the anther to the stigma of another flower of same plant is called geitonogamy.

Xenogamy     

     Transfer of pollen grains from the anther to the stigma of a different plant is called xenogamy.

AGENTS OF POLLINATION

Pollinating agents are either abiotic (wind and water) or biotic (animals).

Pollination by wind  

Wind pollination is more common amongst abiotic pollination. Wind pollination requires that the pollen grains are light and non-sticky so that they can be transport easily. And the plants have well exposed stamens and large often feathery stigma to easily trap pollen grains.

Pollination by water  

Aquatic plants may have aerial, submerged or floating flowers.   It is quite rare in flowering plants.  And the plants have well exposed stamens and large often feathery stigma to easily trap pollen grains.

Pollination by Animals

              Insect pollination

Flowers are mostly pollinated by insects. When an insect visiting a flower to collect food (nectar) pollen from the stamens sticks to the insect and then it travels to another flower these pollen grains are sticks to stigma of the flower.       

                     

                           

        Bird pollination

Many bird pollinated flowers are bright coloured (red or orange) to attract birds, flowers are large in size and most are tubular so that bird can dip their beaks in. while pollen grains from stamen sticks on birds head and pollination occurs.

                                           

                           

     Mammal pollination

Some types of bats and Australian possum are the important mammal pollinators. They pollinate flowers by feed on nectar and pollen.

 

Beautiful Nature

PHOTOSYNTHESIS