Study of Heridity

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Who Initiated the study of heridity?

The resemblance of children to their parents is a matter of common observation.  But it is only from the time of Gregor Mendel that a serious scientific investigation into the mechanism of characteristics from generation to generation, was undertaken. 

Gregor Mendel

This great experimenter published his findings in 1866.  Before him practically nothing was known about this mechanism.

Mendel was not a scientist by vocation.  He developed a great curiosity about inheritance and conducted experiments involving a variety of cultivated plants-garden pea!

Unfortunately the biological world was not ready for his findings.  It was ignored, till rediscovered in 1900!  It was never known to him or his contemporaries that he made one of the greatest scientific contributions of all time.

All organisms develop from a single cell, be it a plant or animal.  This cell is formed by the union of two germ cells one from the male another from the female.

Since Mendel’s time, the term "gene" has replaced his term "character".

Insects

How many kinds of insects are there?

Courtesy: www.wikipedia.org

The insects comprise a separate class – Insecta – among the arthropods.  The first readable fossil record of insects appears in the beginning of the upper carboniferous period – some 320 million years ago.

About 800,000 species have been found all over the world, more than 75% of which belong to four main groups.

Beetles are the most varied insects.  Their total number may be as many as 200,00.  The butterflies and moths may total 140,000 species.  There is no hard and fast rules for telling a butterfly from a moth.

Wasps, Bees and Ants – are the third largest of the insect orders – 115,000 species so far identified.

Then the fourth group – Flies, Gnats and Mosquitoes together about 87,000 species.

There is scarcely a place on this globe that is not home to at least one kind of insect.  Among the largest in the world today is the Atlasmoth of India, which measures 12” from wing tip to wing tip.

Image of Atlas Moth - Courtesy: Wikipedia.org

Nutmeg

What is Nugmeg?

Nutmeg is one of the leading spices, greatly in demand all over the world.  It is actually the dried, powdered kernels of the nut of a tree that belongs to a genus distributed from India and South East Asia to North Australia and the Pacific islands.  About five species are found in India, which includes Myristica fragrans, the source of the nut that yield two valuable spices nutmeg and mace.

Courtesy: keralabackwater.com

The tree grows to a height up to about eight meters, and bears branches that grow parallel to the ground.  The flowers are small and yellowish in colour, and fruits the size of a lemon.  When ripe it has a golden yellowish tint, the outside fleshy portion opens in halves.  With the halves split it discloses the seed inside with a shell like testa covered by a scarlet fibrous aril.  The dried kernels form the reputed nutmeg of commerce.  Mace is the dried aril.

The tree grows well in several parts of India including Kerala, some parts of Tamilnadu, Assam etc.  There is a wild variety Myristica malabarika, or false nutmeg tree which grows in certain parts of Western ghats.  It is of very poor quality and is popularly called Bombay nutmeg and Bombay mace, which are used mainly as adulterants of the costly nutmeg and mace.

Most Nutritious Fruit

The Banana is one of the oldest known fruits in history. It is mentioned in mythology that the great Hanuman had an extensive plantation of plantain! The ripe fruits are presented to deities in temples as special offerings from immemorial times.



Courtesy:photobucket.com

 

It is believed that the home of banana is Assam, Burma, Indo China and other parts of East Asia. Wild varieties are seen in the Western Ghats of the Indian peninsula. The largest number of varieties are found even today in Kerala.

It spread to the West through trade and commerce first by the Arabs who considered banana as a "paradise tree"! early in the 16th century a priest named Father Tomas de Berianga took some chunks of the rhizome to the Americas. He hoped to win over the original inhabitants of the region with this mellow, golden fruit and convert them to Christianity. From the few chunks of rhizome so introduced developed all the thousands of acres of banana plantations which now exists in the tropical regions of the Americas!

The family Musaceae consists of several genera. The plants are all tree-like in form. The stout trunks are encased in the stems of large leaves which rise from the base of the plant. Each plant produces only one fruit. Fully ripe fruits are the most nutritious and most easily digested fruits. It ranks first in the amount of carbohydrates, proteins and calories.





The leading banana produces are Ecuador, Honduras, Costa Rica, Brazil and other countires. Most cultivated varieties have lost power of producing seeds. It is the largest plant in existence without a woody stem.

Banana cultivation is extensive in Kerala, Tamilnadu, Andhra Pradesh, Maharashtra, Karnataka etc. There are about 14 species under cultivation. A great majority belong to Eumusa variety. "Nendran" is the leading commercial variety while "pooven" and "champa" are also equally popular.