Inventors and Scientific Discoveries

The word "hormone" was coined by the English physiologist Ernest H. Starling in connection with the discovery of secretin, the first hormone, in 1902.

•  E.H. Starling in 1905 discovered a signalling molecule or chemical secretin, from pancreatic secretions and named this signalling molecule as hormone.
•  G.W. Harris is known as the father of neuroendocrinology. He worked on the neural control of endocrine system

Luther Gulick coined the word POSDCORB. POSDCORB is used as an acronym for Planning, Organizing, Staffing, Directing, Coordinating, Reporting and Budgeting. It reflects classical view of organization theory. It is broadly used in the field of management.

• Mendel is known as 'Father of Genetics' because he had described basic laws of inheritance. 
• He was not aware of the biological mechanism of inheritance but accurately explained what actually happens when two parents having a contrasting pair of character breed, i.e, the 3:1 ratio between dominant and recessive phenotypes and 1:2:1 genotypic ratio is Mendel's contribution for which he is known as 'Father of Genetics'.

Gregor Johann Mendel first explained scientifically the explanation regarding inheritance using 7 traits in Pea plants(Pisum sativum) in 1886.

Hugo DeVries (Holland), Carl Correns (Germany) and Erich Von Tschermak (Austria) were the three European geneticists who work and rediscovered Mendel's law of heredity in 1900. They expand basic principle of the Mendelian laws of inheritance in more scientific way. Thus, the correct answer is option D.

Gregor Johann Mendel was born in Heizendorf, of Austria. He conducted hybridization experiments on garden pea and first explained the principles of inheritance. Finally, he postulated Law of Inheritance. So he is regarded as Father of Genetics.

So, the correct option is ‘Laws of inheritance’.

In case of pea plant, two types of tall plants are possible- one homozygous and other heterozygous. In case a homozygous, tall pea plant is crossed with a homozygous dwarf pea plant, then all the off springs are tall, i.e., dwarf character masked and is not shown by any of the offspring but next when two of the progeny heterozygous tall pea plants are crossed the dwarf character reappears, even when this time none of the parent was dwarf. The characters are passed on from one generation to the other by gametes. Hence, it is clear that gametes remain pure between generation the gamete with alleles for dwarfness is not disturbed or polluted or altered between generations and even when the F$ _1$ plants were phenotypically tall the allele for dwarfness remained pure and were passed on to F$ _2$ plants.

The Mendelian principles which were discovered in 1865 and 1866 were discovered again by Hugo de Vries, Tsechermark and Correns independently.

He chose garden pea that was easy to grow and to hybridise artificailly.

The plant reproduce well and grows to maturity in a single season.

Mendel then chose to follow seven visible features(unit characters), each represented by two contrasting forms or traits.

Mendel was fortunate in choosing a diploid plant because diploid organisms contain only two sets of chromosomes.

A singe alteration in a trait was therefore demonstrated by a visible differences between varieites.

He restricted his examination to one or very few pairs of contrasting traits in each experiment.

He also kept accurate quatitative records, a necessity in genetic experiments.

In his experiments, no appearance of recombinations and linkage.

So, the correct option is ‘He did not encounter the linkage’.

The Law of Segregation is considered the first law of inheritance, describing how alleles separate during gamete formation. The Law of Dominance is often taught first, but historically, segregation is the fundamental principle derived from the monohybrid cross.

In 1990, three scientists (Correns, de Vries and Von Tschermak) independently rediscovered Mendel's results on the inheritance of character.

Answer is A.