General Awareness · Science General

Inventors and Scientific Discoveries

4,616 Questions

This hub provides questions related to great inventors and their scientific discoveries. It covers the inventors of the telephone, radio, and microchips, alongside Nobel Prize winners. These facts are crucial for the general awareness section of major competitive exams.

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Inventors and Scientific Discoveries Questions

Multiple choice history educational development in india educational development of independent india quality of population human capital formation in india

'Backwash Effect' was firstly introduced by__________.

  1. Gunnar Myrdal

  2. Peter Suderland

  3. Arthur Dunkel

  4. Kindelberger
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

'Backwash effect' was firstly introduced by Gunnar Myrdal. He explained that the growth of one region may hamper the growth of other region from where the resources are used. 

Multiple choice biology habits and habitats of some important animals behavioural science ethology animal behaviour

Which biologist was the first to show that almost all the Australian mammals were marsupials?

  1. Friedrich Wilhelm Humboldt

  2. Sir Joseph Banks

  3. Charles Darwin

  4. Franz Joseph Gall
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • Australia is the only continent (and one of the only two countries - the other being New Guinea) in the world to still have all three of the major groups of mammals: monotremes, marsupials, and placentals
  • Half of Australia's mammal species are marsupials (South America has a few dozen species - all in the opossum family - and a couple of species have found their way into North America, but Australia is the only continent to have such a diverse range or to have marsupials as their most common and conspicuous land mammals)
  • Sir Joseph Banks was one of the first to describe the Australian marsupial, the wombat.

So, the correct answer is 'Sir Joseph Banks'.

Multiple choice botany plant tissues - internal morphology and anatomy theories of meristematic cell development theories of shoot apical meristem development shoot and root apex

The term quiescent centre or zone was proposed by

  1. Schmidt

  2. Foster

  3. Clowes

  4. Nageli
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • The quiescent centre is that part of the root-promeristems of higher plants 
  • They may consist of four cells (minimum) or can go up to 600 cells which show very low mitotic activity.
  • In closed meristem, QC is hemispherical in shape whereas, in open meristem it is disc-shaped.
  • The QC is unusual in the centre of shoots.
  • Frederick Albert Lionel Clowes was a British biologist.
  • He proposed the term Quiescent centre or cytogenerative centre which represents the region of an apical meristem of the root where cell division is very slow.
  • So, the correct answer is 'Clowes'
Multiple choice botany plant tissues - internal morphology and anatomy theories of meristematic cell development theories of shoot apical meristem development shoot and root apex

Histogen theory was proposed by

  1. Bailey

  2. Haberlandt

  3. Hanstein

  4. Schmidt
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The histogen theory was given by Hanstein (1870), According to this, there are 3 groups of initials in the shoot apex. According to Hanstein, the three principal tissues of the root; vascular cylinder, cortex and epidermis originate from three groups of initial cells or histogens, in the apical meristem plerome, periblem and dermatogen respectively. A fourth histogen, the calyptrogen produces the root cap.
Therefore, the correct answer is option C.  

Multiple choice botany plant tissues - internal morphology and anatomy theories of meristematic cell development theories of shoot apical meristem development shoot and root apex

Histogen theory was proposed by

  1. Nageli

  2. Schmidt

  3. Hanstein

  4. Wolf
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • The shoot apical meristems located at the shoot tip in plants are derived from the apical meristematic tissues according to the histogen theory given by Hanstein in 1868.
  • It consists of three distinct layers:-
1) Dermatogen is the primary meristem that forms the outer most layer of a plant or a plant part and forms the epidermis.
2) Periblem is a primary meristem which is located between the plerome and the dermatogen and it forms the cortex.
3) Plerome is the primary meristem that forms the central core of a plant or plant part which gives rise to the stele (includes the vascular tissue, pith and pericycle).
  • The part of plerome from which vascular tissues are formed is called procambium.
So, the correct answer is 'Hanstein'
Multiple choice biology selection and evolution theory of natural selection natural selection evidence for evolution

An experiment to prove that organic compounds were the basis of life, was performed by

  1. Oparin

  2. Miller

  3. Melvin

  4. Fox
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Organic compounds essential for life can be produced by simple inorganic constituents that were the conclusion first derived by Miller and Urey on the basis of their experiment. They took the gases thought to be present in the primitive atmosphere in a sealed flask and exposed them to electric spark. Later on analysis of flask, many organic compounds could be recovered.

Multiple choice biology selection and evolution theory of natural selection natural selection evidence for evolution

Which scientist gave the 'Theory of Continuity of Germplasm'?

  1. Weismann

  2. Mendel

  3. Lamarck

  4. Darwin
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Evolution brings about several modifications to acclimatize with the changing environment. August Weismann (1834-1914) was a neo-Darwinian biologist who proposed the germplasm theory in his book Das Keimplasma. He said that variations are of two types. Some are congenital i.e., organisms are born with them. Others are acquired during the lifetime of a particular plant or animal. It was with this latter type of variations, the acquired characters, that Weismann was very much concerned. He gradually developed his 'Theory of Germplasm' to explain that acquired characters could not be inherited.

Therefore, the correct answer is option A.

Multiple choice biology selection and evolution theory of natural selection natural selection evidence for evolution

The pioneers of organic evolution are 

  1. Karl Landsteiner, Hugo de Vries, Malthus, Darwin

  2. Darwin, Hugo de Vries, Huxley, Lamarck

  3. Darwin, Hugo de Vries, Karl Landsteiner, Lamarck

  4. Malthus, Hugo de Vries, Karl Landsteiner, Lamarck
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Darwin and Lamarck are foundational figures in evolutionary theory. Hugo de Vries is known for his mutation theory, and Huxley was a major proponent of Darwinism.

Multiple choice biology selection and evolution theory of natural selection natural selection evidence for evolution

Theory of ontogeny recapitulates phylogeny was proposed by 

  1. Mendel

  2. Haeckel

  3. Erasmus Darwin

  4. Weismann
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Ernst Haeckel formulated his theory as "Ontogeny recapitulates phylogeny". “Ontogeny recapitulates phylogeny” was a commonly used phrase to explain the evidence supporting evolution. Ontogeny is “the complete developmental history of the individual organism,” and phylogeny is defined as “the complete evolutionary history of a group of organisms,”. Thus, this phrase means that the evolutionary history of a group of organisms is repeated during the developmental history of an individual organism of that group. This idea is also known as recapitulation. 

Therefore, the correct answer is option B.

Multiple choice types of cells electricity physics

First electro chemical cell was designed by?

  1. Laclanche

  2. Faraday

  3. Galvanic

  4. Some one other than those mentioned above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The battery made by Volta is credited as the first electrochemical cell. It consists of two electrodes: one made of zinc, the other of copper. The electrolyte is either sulfuric acid mixed with water or a form of saltwater brine.

Multiple choice physics upthrust in fluids, archimedes' principle and floatation experimental verification of archimedes' principle archimedes' principle archimedes' principle and its applications

Archimedes' major contribution / discovery was:

  1. Photoelectric effect

  2. Principle of buoyancy

  3. Wave theory of light

  4. Law of inertia
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Answer is B

Archimedes' principle indicates that the upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially submerged, is equal to the weight of the fluid that the body displaces. Because of this buoyancy a body is able to float or submerge over liquid surface.