NEET Biology Origin Of Life MCQs

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Biology MCQ For NEET With Answers Origin Of Life

Question 1. What does evolutionary biology refer to?

  1. The study of the history of life forms on earth
  2. Study of pedigrees of life forms on earth
  3. It is equivalent to demography
  4. It is equivalent to anthropology

Answer: 1. The study of the history of life forms on earth

Evolutionary biology is the study of the history of life forms on Earth. The word ‘evolution’(Latin-volvere) means to unfold or unroll. In a broad sense, evolution simply means an orderly change from one condition to another.

Evolution is a continuous process in which progeny with modification is produced.

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Question 2. What is observed in evolution?

  1. A sudden change occurring in a population
  2. Progeny with modifications
  3. It is a discontinuous process
  4. All of the above

Answer: 2. Progeny with modifications

The term evolution means that living beings constantly change. It is a continuous process in which progeny with modification is produced.

Read And Learn More: NEET Biology Multiple Choice Question And Answers

Question 3. The evolution occurring at a genetic level is called

  1. Macroevolution
  2. Mega evolutions
  3. Inorganic evolution
  4. Microevolution

Answer: 4. Microevolution

Microevolution is a series of changes within a species due to gene mutations and the accumulation of variations. It is an evolution occurring genetically.

Question 4. The term ‘evolution’ was coined by

  1. Charles Darwin
  2. Francesco Redi
  3. Herbert spencer
  4. Aristotle

Answer: 3. Herbert Spencer

The term evolution was given by Herbert Spencer

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NEET Biology Origin Of Life MCQs

NEET Biology Origin of Life MCQs with answers

Question 5. Which of the following is the correct sequence of events in the origin of life?

  1. Formation of protobionts
  2. Synthesis of organic monomers
  3. Synthesis of organic polymers
  4. Formation of dna-based genetic systems

Choose the correct option

  1. 1, 2, 3, 4
  2. 1, 3, 2, 4
  3. 2, 3, 1, 4
  4. 2, 3, 4, 1

Answer: 3. 2, 3, 1, 4

The correct sequence of events in the origin of life is as follows

Synthesis of organic monomers
Synthesis of organic polymers
Formation of protobionts
Formation of DNA-based genetic systems.

“which one is not an example of analogous structures “

Question 6. Which of the following gas was absent in the atmosphere at the time of the origin of life?

  1. NH3
  2. H2
  3. O2
  4. Ch4

Answer: 3. O2

Primitive conditions on the earth were high temperatures, volcanic storms, and a reducing atmosphere containing CH4, NH3, H2, etc. There was no oxygen on the primitive earth

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Question 7. Consider the following statements regarding the origin of life.

The earliest organisms that appeared on the earth were non-green and presumably anaerobes.
The first autotrophic organisms were the chemoautotrophs that never released oxygen.
Choose the correct option.

  1. Statement 1 is correct, but 2 is incorrect
  2. Statement 1 is incorrect, but 2 is correct
  3. Both statements 1 and 2 are correct
  4. Both statements 1 and 2 are incorrect

Answer: 3. Both statements 1 and 2 are correct

The first originated organisms were prokaryotic chemoheterotrophs and oxygen was not available on earth at that time, so it must be anaerobic too. Even the first autotrophs were dependent on chemicals as oxygen was not released. Thus, they were non-green chemoautotrophs

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Question 8. Evolution means mp

History of race
Development of race
History and development of race with variations
Progressive development of the race
Answer: 3. History and development of race with variations

Evolution simply means an orderly change from one condition to another. Evolution is a continuous process in which progeny or race with modifications or variations are produced.

Question 9. Origin of life took place in/on

Water
Air
Mountains
Land
Answer: 1. Water

Primitive life originated in the water bodies on the primitive earth from inanimate matter by chemical evolution through a series of chemical reactions about 4 billion years ago

Question 10. The sequence of origin of life could be

  1. Organic materials → inorganic materials → non-colloidal aggregate → eobiont → cell
  2. Inorganic materials → organic materials → colloidal aggregates → eobiont → cell
  3. Inorganic materials → organic materials → eobiont → cell → colloidal aggregate
  4. Inorganic materials → inorganic materials → eobiont → cell → colloidal aggregate

Answer: 2. Inorganic materials → organic materials → colloidal aggregates → eobiont → cell

The sequence of origin of life is as follows Free atom → inorganic materials → organic materials → colloidal aggregates → origin of coacervates like droplets (Eobionts) → prokaryotes (Single cell organism) → eukaryotes (Multicellular organism)

Question 11. The origin of life as a result of chemical evolution was properly explained by

  1. Fox
  2. Oparin
  3. Watson
  4. Haeckel
  5. Mendel
  6. Crick

Choose the correct option.

  1. 1 and 2
  2. 3 and 4
  3. 5 and 6
  4. Only 2

Answer: 4. Only 2

Oparin and Haldane explained the chemical evolution of life.

Biology MCQ For NEET With Answers

Question 12. According to one of the most widely accepted theories, earth’s atmosphere before the origin of life consisted of a mixture of

  1. O3, CH4 , O2 and HO2
  2. O2, NH3, CH4 and HO2
  3. H2, CO2, NH3 and CH4
  4. CH4, NH3, HO2 and HO2 vapours

Answer: 4. CH4, NH3 , H2 and HO2 vapours

According to one of the most widely accepted theories, the earth’s atmosphere before the origin of life consisted of a mixture of CH4, NH3, H2 and water vapours.

The atmosphere of primitive Earth was strongly reducing. At high temperatures (5000°C to 6000°C) elements like hydrogen, oxygen, carbon and nitrogen could not exist in a free state.

These combined variously either among themselves or with metals forming oxides, carbides and nitrides.

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Question 13. The idea of the ‘fiery origin of the earth’ was given by

  1. Lamaitre
  2. James jeans
  3. Haldane
  4. Oparin

Answer: 2. James’ jeans

The idea of the fiery origin of the earth was given by James Jeans. According to the Tidal creation theory as proposed by James Jeans, a huge tide was caused by the sun’s surface by the gravitational pull of a stray star.

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It was followed by a scattering of bits of the crest of a high wave into space resulting in the formation of planets. Thus, each planet, including Earth was a fiery chunk that cooled down over billions of years.

Question 14. Which of the following compounds has a very important role in pre-biotic evolution?

  1. CH4
  2. SO2
  3. SO3
  4. NO

Answer: 1. CH4

CH4 (methane) was probably the first organic compound formed on primitive earth, and thus has an important role in pre-biotic evolution.

\(\mathrm{CH}_4+2 \mathrm{O}_2 \rightarrow \mathrm{CO}_2+2 \mathrm{H}_2 \mathrm{O}\)

Biology MCQ For NEET With Answers

Question 15. The correct sequence for the manufacture of the gases on the primitive earth is

  1. NH3, nucleic acid, protein and carbohydrate
  2. Protein, carbohydrate, water and nucleic acid
  3. NH3, protein, carbohydrate and nucleic acid
  4. NH3, water, nucleic acid and protein

Answer: 4. NH3, water, nucleic acid and protein

The correct sequence for the manufacture of the gases on the primitive earth is NH3, water, nucleic acid and protein. There were abundant hydrogen atoms in the primitive atmosphere.

First H2 combined with nitrogen to form ammonia and later it combined with molecular O2 to form water.

Later, CH4 H2O and NH3, combined to form amino acids which got polymerised into proteins.

H2 -bases, sugars and phosphates combined to form nucleic acids.

Question 16. One of the possible early sources of energy was/was aims

  1. CO2
  2. Chlorophyll
  3. Green plants
  4. Uv-rays and lightening

Answer: 4. Uv-rays and lightening

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In the primitive atmosphere, the external sources of energy were – solar radiations such as ultraviolet light, X-rays, etc. energy from electrical discharges like lightning

Question 17. The first organisms to evolve on the earth were

  1. Saprotrophs
  2. Photoautotrophs
  3. Chemoautotrophs
  4. Chemoheterotrophs

Answer: 3. Chemoautotrophs

Both statements 1 and 2 are correct. The first originated organisms were prokaryotic chemoheterotrophs and oxygen was not available on earth at that time, so it must be anaerobic too.

Even the first autotrophs were dependent on chemicals as oxygen was not released. Thus, they were non-green chemoautotrophs

Question 18. Origin of life is also called

  1. Biogenesis
  2. Protobiogenesis
  3. Biopoiesis
  4. All of these

Answer: 4. All of these

Biogenesis is the production of new living organisms or organelles. The origin of life on the earth is called proto-biogenesis.

Biopoiesis is a process by which living organisms are thought to develop from non-living matter. So, the origin of life is also called biogenesis, proto-biogenesis and biopoiesis

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Question 19. Which of these are considered most essential in the origin of life?

  1. Enzymes
  2. Nucleic acids
  3. Carbohydrates
  4. Proteins

Answer: 2. Nucleic acids

Nucleic acids are the polymer of nucleotides that exhibits the unique ability of self-replication and self-perpetuation.

Owing to their ability of self-replication, nucleic acids serve as genetic material and carriers of heredity traits from one generation to the next which is a pre-requisite for living organisms.

Thus, nucleic acids are the most essential in the origin of life

Question 20. The concept of evolution was given by Punjab

  1. Darwin
  2. Aristotle
  3. Lamarck
  4. Empedocles

Answer: 4. Empedocles

Empedocles, a philosopher of Greek descent, lived in Sicily in the 5th century BCE.

Empedocles developed a theory of evolution that consisted of natural elements being acted upon by natural forces to create the world that we know today.

Question 21. From the point of view of early chemical evolution that preceded the origin of life on Earth, the most important simple organic molecules formed were

  1. Sugars and amino acids
  2. Glycerol and fatty acids
  3. Purines and pyrimidines
  4. All of the above

Answer: 4. All of the above

The early inorganic molecules interacted and produced simple organic molecules such as simple sugars (e.g. ribose, deoxyribose, glucose, etc.), nitrogenous bases (e.g. purines, pyrimidines), amino acids, glycerol, fatty acid, etc.

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Question 22. The simple organic compounds that may have first evolved in the direction of the origin of life on Earth, may have been

  1. Proteins and amino acids
  2. Proteins and nucleic acids
  3. Urea and nucleic acids
  4. Urea and amino acids

Answer: 2. Proteins and nucleic acids

Proteins and nucleic acids were the first to evolve on Earth which was required for the origin of life. Protein originated before the nucleic acids. In the nucleic acids (RNA and DNA), RNA was the first genetic material

Question 23. Life cannot originate today because

  1. Raw materials are not available
  2. Life has already originated
  3. Today’s atmosphere is reducing
  4. Today’s atmosphere is oxidising

Answer: 4. Today’s atmosphere is oxidising

An atmosphere containing free oxygen would be fatal to all origins of life schemes. While oxygen is necessary for life, free oxygen would oxidise and thus, destroy all organic molecules required for the origin of life. Thus, life cannot originate in existing oxidising atmosphere conditions.

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Question 24. The source of energy at the time of the origin of life was

  1. Volcanic eruptions, radioactive decay and lightning
  2. Burning of fossil fuels
  3. Cosmic rays only
  4. Lightning only

Answer: 1. Volcanic eruptions, radioactive decay and lightning

New analysis shows that radioactive decay, lightning and gases from volcanic eruptions were the sources of energy at the time of origin and these could have given rise to the first life on earth

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Question 25. Which one of the following is the correct sequence of chemical substances produced during the origin of life on the earth?

  1. Water, amino acid, nucleic acid and enzyme
  2. Glucose, amino acid, nucleic acid and protein
  3. Amino acid, ammonium phosphate and nucleic acid
  4. Ammonia, amino acid, protein and nucleic acid

Answer: 1. Water, amino acid, nucleic acid and enzyme

Life was preceded by biomolecules. Biomolecules evolved from simple inorganic molecules present in the primitive atmosphere on Earth like methane, ammonia, hydrogen, nitrogen and water vapour.

These simple molecules combined under the influence of thunder lightning to generate amino acids.

Aggregates of amino acids later on produced nucleic acids and biological catalysts, i.e. enzymes. Thus, the correct sequence is water, amino acid, nucleic acid and enzyme.

Question 26. It is useful to study the origin and evolution of life because

  1. It cannot exist anywhere else
  2. We learn about unity and diversity
  3. We learn that the human species has the responsibility to conserve nature
  4. The human species is not the most evolved

Answer: 2. We learn about unity and diversity

The remarkably diverse forms of life on this planet arose from evolutionary processes. A striking unity underlies the diversity of life. For example, DNA is the universal genetic language common to all organisms.

Similarities between organisms are evident at all levels of the biological hierarchy.

Question 27. Which of the following statements does not explain the usefulness of the study of the origin and evolution of life?

  1. We learn that life can exist anywhere else also
  2. We learn about the unity and diversity of living organisms
  3. The human species is the most evolved, so no harm can be done to us
  4. We learn that human beings have the responsibility to conserve nature

Answer: 3. The human species is the most evolved, so no harm can be done to us

The statement in option 3 does not explain the usefulness of the study of the origin and evolution of life. It can be corrected as Evolution is a theory of change over the course of time.

Not only humans but many species are the most evolved. Rest all options are correct

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Question 28. An examination of fossils and other materials indicates that

  1. Life has been in existence since the beginning of the earth
  2. Life appears to have been in existence for more than three billion years
  3. Life may not have existed on Earth until about two billion years ago
  4. Life was transported on the earth from some other planets

Answer: 2. Life appears to have been in existence for more than three billion years

The oldest known fossils are around 3.5 billion years old, 14 times the age of the oldest dinosaurs.

But the fossil record may stretch back still further. For instance, in August 2016 researchers found what appear to be fossilised microbes dating back 3.7 billion years

Question 29. Galaxies of the present-day universe were formed due to condensation by …… Earth, situated in the milky way galaxy is said to have been formed about ……. Ago. Gases such as NH4, CO2, water vapour and……. Were released. Choose the correct options in order

  1. Gravitation, 4.5 billion years, methane
  2. Acceleration, 2.5 billion years, sulphur
  3. Freezing, 1.5 billion years, ethane
  4. Acceleration, 4.5 billion years, methane

Answer: 1. Gravitation, 4.5 billion years, methane

Question 30. How old is our universe?

  1. 10 Billion years old
  2. 20 Billion years old
  3. 15 Billion years old
  4. 200 Billion years old

Answer: 2. 20 Billion years old

The origin of life on Earth is estimated to have occurred around 3.5 billion or 3500 million years ago dusters of galaxies comprise the universe.

Question 31. The origin of life on earth dates back to hp

  1. 6000 million years
  2. 3500 million years
  3. 2000 million years
  4. 10,000 million years

Answer: 2. 3500 million years

The origin of life on earth is estimated to have occurred around 3.5 billion or 3500 million years ago

Question 32. After about how many years of the formation of the earth, life appeared on this planet?

  1. 500 Billion years
  2. 50 million years
  3. 500 million years
  4. 50 Billion years

Answer: 3. 500 Million years

Life appeared 500 million years after the formation of Earth, i.e. almost 4 billion years back.

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Question 33. The long gap of 3500 million years between the origin of the earth and of life on it was due to a lack of

  1. Oxygen
  2. Water
  3. Dna
  4. Suitable temperature

Answer: 4. Suitable temperature

The earth is believed to be originated about 4500 million years ago (in the Precambrian Era).

Earlier earth’s surface was too hot (about 1000°C). At this temperature, life was not possible and water molecules existed in vapour form. It took a long time to cool down the earth.

About 3500 million years ago, the earth’s surface became cool enough to hold water and the large water bodies or the first ocean came into existence.

It marked the beginning of the first life on the earth and water was the most essential factor for the origin of life.

Thus, a long gap between the origin of earth and life was due to the lack of suitable temperature

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Question 34. The temperature in the interior of the sun is above 20000000°c, the reason for this high temperature is

  1. Various exothermic reactions are taking place
  2. Fusion converts the hydrogen of the sun to helium
  3. Collision of particles releasing energy
  4. None of the above

Answer: 2. Fusion converting hydrogen of the sun to helium

The temperature in the interior of the sun is about 20000000°C. The reason for this high temperature is fusion reactions that convert the hydrogen of the sun to helium

Question 35. The discovery of fossils of cyanobacteria indicates that life originated sometime

  1. Prior to 4600 million years ago
  2. Between 4600 and 3600 million years ago
  3. Around 3600 million years ago
  4. During some other period

Answer: 3. Around 3600 million years ago

Cyanobacteria (Cyanophyta) are a group of bacteria, previously known as blue-green algae.

They are unicellular and non-motile, often coated with mucilaginous slime and the photosynthetic membranes occur as thylakoids within the cell cytoplasm rather than being in a membrane-bounded chloroplast.

The cyanobacteria have an extensive fossil record.

Question 36. Anaerobic photosynthetic bacteria appeared on the Earth about

  1. 500 million years ago
  2. 1500 million years ago
  3. 2500 million years ago
  4. 3500 million years ago

Answer: 4. 3500 Million years ago

Evolution of life-3800-4200 million years back (mya). Evolution of bacteria 3500-3800 mya. Evolution of cyanobacteria 3300- 3500 mya. Evolution of eukaryotic algae 1600 mya.

Question 37. Who proposed the big-bang theory?

  1. Father Suarez
  2. Abbe lemaitre
  3. Arno allen penzias
  4. Edwin p hubble

Answer: 2. Abbe lemaitre

There are several theories regarding the origin of the universe, but the most accepted is the Big Bang theory.

It was proposed by Abbe Lemaitre in 1931. According to the Big Bang theory, about 15-20 billion years ago, cosmic matter was in a condensed form consisting of high-energy neutrons.

The explosion took place due to the movement of these neutrons which broke the condensed matter and scattered its fragments into space at an enormous velocity making a Big Bang sound and thus, the theory came to be known as the Big Bang theory.

Question 38. An attempt to explain the origin of ……………… Was made by big-bang theory.

  1. Earth
  2. Solar-system
  3. Universe
  4. Continents

Answer: 3. Universe

There are several theories regarding the origin of the universe, but the most accepted is the Big Bang theory.

It was proposed by Abbe Lemaitre in 1931. According to the Big Bang theory, about 15-20 billion years ago, cosmic matter was in a condensed form consisting of high-energy neutrons.

The explosion took place due to the movement of these neutrons which broke the condensed matter and scattered its fragments into space at an enormous velocity making a Big Bang sound and thus, the theory came to be known as the Big Bang theory.

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Question 39. Assertion According to the big-bang hypothesis, about 20 billion years ago the universe was a big ball of only neutrons. Reason (r) movement of these particles is known to generate tremendous heat which caused explosion due to temperature and pressure changes.

  1. Both a and r are true and r is the correct explanation of a
  2. Both a and r are true, but r is not the correct explanation of a
  3. A is true, but r is false
  4. Both a and r are false

Answer: 1. Both a and r are true and r is the correct explanation of a

Both A and R are true and R is the correct explanation There are several theories regarding the origin of the universe, but the most accepted is the Big Bang theory.

It was proposed by Abbe Lemaitre in 1931. According to the Big Bang theory, about 15-20 billion years ago, cosmic matter was in a condensed form consisting of high-energy neutrons.

The explosion took place due to the movement of these neutrons which broke the condensed matter and scattered its fragments into space at an enormous velocity making a Big Bang sound and thus, the theory came to be known as the Big Bang theory.

Question 40. Assertion big-bang theory is based on studies of sir james jeans. Reason (r) he gave the theory of steady state.

  1. Both a and r are true and r is the correct explanation of a
  2. Both a and r are true, but r is not the correct explanation of a
  3. A is true, but r is false
  4. Both a and r are false

Answer: 3. A is true, but r is false

A is true, but R is false and Reason can be corrected as In cosmology, the steady-state model is an alternative to the Big Bang theory of the evolution of the universe.

The steady-state model was proposed by three individuals in 1948, Hermann Bondi, Thomas Gold and Fred Hoyle

Question 41. According to scientists, the big bang occurred approximately ………………….. Years ago.

  1. 100 Million-200 million
  2. 100 Thousand
  3. 1 Billion
  4. 15-20 Billion

Answer: 4. 15-20 Billion

According to scientists, the Big Bang occurred about 15-20 billion years ago.

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Question 42. According to the theory of special creation

  1. All the living beings on earth were created by god or supernatural power
  2. All the living beings on earth were in the form of spores or microorganisms
  3. All the living beings on earth originated from non-living material
  4. All living beings originated from pre-existing living forms

Answer: 1. All the living beings on earth were created by god or supernatural power

The theory of special creation states that life was created by God or supernatural power, in the same conditions as they exist now.

Question 43. The theory of special creation was given by

  1. Weismann
  2. Helmont
  3. Maupertuis
  4. Father Suarez

Answer: 4. Father Suarez

Father Suarez was a strong believer (supporter) of the theory of special creation. He believed that the whole life on earth was formed in 6 days.

Question 44. The theory of special creation argues that

  1. All living organisms were created as they are in present times.
  2. Diversity was always the same since creation.
  3. Earth is 4000 years old.

Choose the right option to complete the given statement.

  1. 1 and 2
  2. 2 and 3
  3. 1 and 3
  4. 1, 2 and 3

Answer: 4. All statements are correct.

The greatest supporter of the special creation theory was Father Suarez.

According to this theory, life was created by supernatural powers and the world was created in six days.

The earth is 4000 years old. All the diversity has existed since creation.

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Question 45. The cosmozoic theory was given by

  1. Darwin
  2. Richter
  3. Aristotle
  4. Van Baer

Answer: 2. Richter

Cosmozoic theory or the theory of panspermia was proposed by Richter in 1865 and was later supported by Arrhenius in 1908.

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Question 46. The extra-terrestrial origin of life was proposed by

  1. Natural selection
  2. Origin of species
  3. Continental drift
  4. Theory of panspermia

Answer: 4. Theory of panspermia

The theory of panspermia was proposed by Richter. According to this theory, protoplasm reached Earth in the form of spores or germs from unknown or extra-terrestrial parts of the universe with cosmic dust and subsequently evolved into various forms of life.

Question 47. Assertion Arrhenius considered panspermia as mainly responsible for the transfer of germs from other planets to Earth.  Reason (r) present-day study of meteorites like allan hill: 84001 which was knocked out from Mars in Antarctica, is rich in aromatic hydrocarbons deposited by biological activity.

  1. Both a and r are true and r is the correct explanation of a
  2. Both a and r are true, but r is not the correct explanation of a
  3. A is true, but r is false
  4. Both a and r are false

Answer: 2. Both a and r are true, but r is not the correct explanation of a

Both A and R are true, but R is not the correct explanation of A. Arrhenius considered panspermia as mainly responsible for the transfer of germs from other planets to Earth.

The cosmozoic or interplanetary theory was put forward by Richter and supported by Arrhenius and others.

It stated that life had reached the earth from some other heavenly body in the form of resistant spores.

Present day study of a meteorite called Allan Hills 84001 which was knocked out from Mars in Antarctica revealed that it is rich in aromatic hydrocarbons deposited by biological activity.

Microscopic fossils of bacteria in the meteorite suggested that these organisms originated on Mars, but these claims are controversial

Question 48. Who disapproved of the theory of spontaneous generation?

  1. Urey and miller
  2. Oparin
  3. Redi, spallanzani and pasteur
  4. Aristotle

Answer: 3. Redi, spallanzani and pasteur

The theory of spontaneous generation is also called abiogenesis or autogenesis. This theory states that life originated from non-living by itself or
spontaneous manner.

Francesco Redi, Louis Pasteur and Spallanzani disapproved of the theory of abiogenesis

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Question 49. Louis Pasteur is famous for

  1. Recapitulation theory
  2. The germ theory of diseases
  3. Cell theory
  4. Both 1 and 3

Answer: 2. Germ theory of diseases

The germ theory of disease is the currently accepted scientific theory for many diseases.

The more formal experiments on the relationship between germ and disease were conducted by Louis Pasteur between the years 1860 and 1864

Question 50. Which one of the following experiments suggested that the simplest living organisms could not have originated spontaneously from non-living matter?

  1. Microbes did not appear in stored meat
  2. Larvae could appear in decaying organic matter
  3. Microbes appeared from unsterilised organic matter
  4. The meat was not spoiled when heated and kept sealed in a vessel

Answer: 4. Meat was not spoiled when heated and kept sealed in a vessel

Francesco Redi, an Italian physician, took the flesh and cooked it so that no organisms were left alive.

Then he placed flesh in three jars, of which, one was uncovered, the second was covered with parchment and the third one was covered with fine muslin.

He kept these jars for a few days and observed that maggots developed only in the uncovered jar though the flies also visited other jars.

Thus, an experiment in option (d) suggested that the simplest living organisms could not have originated spontaneously from non-living matter

Question 51. The theory of spontaneous generation or abiogenesis was disproved by swan flask experiments by

  1. Ar Wallace
  2. Francesco redi
  3. Louis pasteur
  4. Ai oparin
  5. Sidney fox

Answer: 3. Louis pasteur

Louis Pasteur conducted an experiment with a swan-necked flask to discredit the theory of spontaneous generation. The infusion was boiled till the steam rushed out of the neck of the flask.

Microorganisms did not develop when the flask was left open. When its neck was broken, bacteria appeared immediately.

Question 52. Louis Pasteur’s view on the origin of life is that

  1. Life originated within six days
  2. Life originated from the living organisms
  3. Only life originated spontaneously from the non-living substances
  4. Life came from other planets

Answer: 2. Only life originated spontaneously from the non-living substances

Louis Pasteur carefully experimentally demonstrated that, life comes only from pre-existing life.

He showed that in pre-sterilised flasks life did not come from killed yeast, while in another flask open to the air, new living organisms arose from ‘killed yeast

Question 53. Van Helmont believed that mice originate from wheat grains and dirty clothes. He, therefore, favoured the theory of

  1. Biogenesis
  2. Spontaneous generation
  3. Pangenesis
  4. Cosmozoic

Answer: 2. Spontaneous generation

Abiogenesis is the spontaneous generation theory, according to which fully formed living organisms sometimes arise from non-living matter.

The theory of abiogenesis or spontaneous generation was based on ancient superstition rather than any scientific research.

This theory was believed and supported by Thales, Anaximander, Newton, Descartes and van Helmont. van Helmont described that mice arise from the wheat barns and sweaty shirts kept in a pot for 21 days in the dark

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Question 54. To disprove the theory of the spontaneous origin of life, the nutritious broth in glass flasks was boiled and sealed. The bottle remained clear and sterile. Who was the first to perform such an experiment?

  1. Pasteur
  2. Lazzaro spallanzani
  3. Oparin
  4. Francesco redi

Answer: 2. Lazzaro spallanzani

Spallanzani disapproved of the theory of abiogenesis (spontaneous generation).

He experimented with animal and vegetable broths and boiled them for several hours. He soon after sealed them to ensure the broths were never infested with microorganisms.

From this experiment, he concluded that high temperatures had killed all living organisms in the broths and without them, life did not appear. When the broths were left exposed to air, it was soon invaded by microorganisms

Question 55. The accepted theory of the origin of life is

  1. Spontaneous generation theory
  2. Self-assembly theory
  3. Biogenesis theory
  4. Cosmozoic theory

Answer: 3. Biogenesis theory

The most accepted theory of the origin of life today is the biogenesis theory

Question 56. The term ‘proto biogenesis’ is used for the theory of

  1. Biochemical origin of life
  2. Panspermia
  3. Spontaneous generation
  4. Special creation

Answer: 1. Biochemical origin of life

The term proto-biogenesis is used for the theory of the biochemical origin of life. Protobiogenesis refers to the origin of the first life form non-living chemical assemblages.

Question 57. According to abiogenesis, life originates from

  1. Non-living
  2. Other planes
  3. Pre-existing life
  4. Spontaneously

Answer: 1. Non-living

Abiogenesis states that life originated from non-living things in a spontaneous manner

Question 58. The idea that life originates from pre-existing life is referred as

  1. Biogenesis theory
  2. Special creation theory
  3. Abiogenesis theory
  4. Extra-terrestrial theory

Answer: 1. Biogenesis theory

Biogenesis theory states that life originates only from pre-existing life

Question 59. The abiogenesis occurred about how many billion years ago?

  1. 1.2 billion
  2. 1.5 billion
  3. 2.5 billion
  4. 3.5 billion

Answer: 4. 3.5 billion

Abiogenesis was supposed to occur about 3.5 billion years ago

Question 60. Select the wrong pair.

  1. Haldane -hot dilute soup
  2. Oparin -protobiont
  3. Fox -coacervates
  4. Spallanzani -approved abiogenesis
  5. Francesco redi -biogenesis

Answer: 4. Francesco redi -biogenesis

Option 4 is the wrong pair and it can be corrected as Spallanzani disapproved abiogenesis and approved biogenesis. The rest of other options are correctly matched pair.

Question 61. With reference to the origin of life, Aristotle believed in

  1. Cosmozoic theory
  2. Special creation
  3. Abiogenesis
  4. Panspermia

Answer: 3. Abiogenesis

Aristotle developed his Scala Naturae, or Ladder of Life, to explain his concept of the advancement of living things from inanimate matter to plants, then animals and finally man. He supported the theory of spontaneous generation (abiogenesis or autogenesis).

Question 62. The concept of chemical evolution is based on

  1. Interaction of water, air and clay under intense heat
  2. Effect of solar radiation on chemicals
  3. Possible origin of life by a combination of chemicals under suitable environmental conditions
  4. Crystallisation of chemicals

Answer: 3. Possible origin of life by a combination of chemicals under suitable environmental conditions

The concept of chemical evolution is based on the possible origin of life by a combination of chemicals under suitable environmental conditions.

The distribution of elements in the cosmos is the result of many processes in the history of the universe.

It provides a powerful tool to study the Big Bang, the density of baryonic matter, nucleosynthesis and the formation and evolution of stars and galaxies.

Question 63. The theory of the origin of life as a result of chemical evolution has been properly explained by

  1. Stanley miller
  2. Darwin
  3. Oparin
  4. S fox

Answer: 3. Oparin

Oparin (1894-1980) was a Russian scientist. He published his book ‘The Origin of Life in 1936.’ In his book, he mentioned that the origin of life takes place as a result of chemical evolution

Mock test on Origin of Life for NEET preparation

Question 64. Oparin and Haldane’s theory is also known as

  1. The modern theory of the origin of life
  2. Chemical theory of the origin of life
  3. Naturalistic theory
  4. All of the above

Answer: 4. All of the above

The theory of chemical evolution is also called the modern theory of evolution or naturalistic theory of evolution.

Oparin and Haldane proposed that the first form of life could have come from pre-existing non-living organic molecules (e.g. RNA, protein, etc.) and that the formation of life was preceded by chemical evolution, i.e. formation of diverse organic molecules from inorganic constituents.

Question 65. In the Oparin theory, the most important/ essential element was

  1. Proteins Jharkhand
  2. Oxygen
  3. Amino acids
  4. Nitrogen, ammonia and methane

Answer: 3. Amino acids

The Oparin-Haldane hypothesis suggested that life arose gradually from inorganic molecules, with building blocks like amino acids forming first and then, they combined to make complex polymers.

Thus, amino acids were the most essential element in Oparin theory.

Question 66. Oparin and Haldane proposed

  1. The theory of natural selection
  2. That migration affects the genetic equilibrium
  3. That mutation caused speciation
  4. That the first form of life could have come from pre-existing non-living organic molecules
  5. That evolution of life forms had been driven by the use and disuse of organs

Answer: 4. That evolution of life forms had been driven by the use and disuse of organs

According to Oparin-Haldane’s theory of the origin of life, ‘life’ originated on earth spontaneously from preexisting non-living organic molecules.

First inorganic compounds and then organic compounds were formed in accordance with ever-changing environmental conditions.

This is called chemical evolution which cannot occur under present environmental conditions on Earth.

Question 67. Abiogenic organic matter of sea at the time of origin of life was called ‘hot dilute soup’ by

  1. M calvin
  2. Sl miller
  3. F redi
  4. Jbs haldane

Answer: 4. Jbs haldane

JBS Haldane described the sea containing biomolecules like monosaccharides, amino acids, purines, pyrimidines, fatty acids and glycerol in abundance as the hot dilute soup or primitive broth. The hot dilute soup was without oxygen.

Question 68. According to the abiogenic origin of life proposed by Oparin, …………… Was the simplest organic compound to arise.

  1. Organic acids
  2. Hydrocarbons
  3. Carbohydrates
  4. Proteins.

Answer: 2. Hydrocarbons

In 1924, Oparin officially put forward his influential theory that life on earth developed through the gradual chemical evolution of carbon-based molecules called hydrocarbons, which was the simplest organic compound in a primordial soup.

Question 69. The possible details of the chemical evolution of the most elementary forms of life were particularly well-worked out experimentally by

  1. Haldane
  2. sydney w fox
  3. Urey and miller
  4. Ai pain

Answer: 3. Urey and Miller

Experimentally, the chemical theory of evolution was proved by SL Miller
and HC Urey in 1953.

They performed electric experiments and observed the formation of sugar, nitrogen bases, pigment and fats

Question 70. To determine which molecules might have formed spontaneously on early Earth, Stanley Miller used an apparatus with an atmosphere containing

  1. Oxygen, hydrogen and nitrogen
  2. Oxygen, hydrogen, ammonia and water vapour
  3. Oxygen, hydrogen and methane
  4. Hydrogen, ammonia, methane and water vapour

Answer: In his experiment, Miller used a mixture of methane, ammonia, hydrogen and water. The mixture was exposed to electric discharges, followed by condensation and then boiling.

He analysed the chemical composition of the liquid inside the apparatus and found a large number of simple organic compounds including some amino acids. Miller proved that organic compounds were the basis of life.

Question 71. Formation of which complex molecules was noticed by Urey and Miller when they subjected substances like NH3, CH4 and HO2 to electric discharge?

  1. H2SO3
  2. Amino acids
  3. Hydroponics
  4. HCN

Answer: 2. Amino acids

Experimentally, the chemical theory of evolution was performed by SL Miller and HC Urey in 1953. They created electric discharge in a closed flask containing water vapour at 800 °C and observed the formation of amino acids

Question 72. Which of the following statements about Miller and Urey’s experiment
is correct?

  1. The gases used were only methane (CH4 ) and ammonia (NH3)
  2. A continuous magnetic wave was passed through the system, to simulate lightning storms believed to be common on the early earth
  3. Experiments showed that organic compounds such as amino acids, could not be made easily under the conditions believed to be present on the early earth
  4. None of the above

Answer: 4. None of the above

All statements are incorrect about Miller and Urey’s experiment. In Stanley L Miller and Harold C Urey’s experiment, the gases used were methane (CH4 ), ammonia (NH3), hydrogen (H2) and water (HO2 ).

Next, a continuous electric current was passed through the system, to simulate lightning storms that were believed to be common on the early earth.

This experiment showed that organic compounds such as amino acids, which are essential to cellular life, could be made easily under the conditions that were believed to be present on the early earth.

Question 73. What did Miller observe after the completion of his experiment?

  1. Amino acids
  2. Organic compounds
  3. Peptides
  4. All of the above

Answer: 4. All of the above

Miller circulated four gases methane, ammonia, hydrogen and water vapour in an air-tight apparatus and passed electrical discharges from electrodes at 800°C.

After a week, he found a large number of simple organic compounds including amino acids such as alanine, glycine, aspartic acid and small peptides.

Other substances such as urea, hydrogen cyanide, lactic acid and acetic acid were also present.

Question 74. The ratio of methane, ammonia and hydrogen in Stanley Miller’s experiment was

  1. 3: 1: 2
  2. 2: 1: 2
  3. 1 : 2: 1
  4. 5: 4: 1

Answer: 2. 2: 1: 2

The ratio of methane, ammonia and hydrogen in Miller’s experiment was 2: 1: 2.

Question 75. The given diagram represents Miller’s experiment. Choose the correct combination of labelling for a, b, c, d and e.

NEET Biology Origin Of Life MCQs Miller’s experiment

  1. A–electrodes, B–NH4+ H2 + HO2 + CH4, C–cold water, D–vacuum, E–u-trap
  2. A–electrodes, B–NH4 + H2 + co2 + ch 3, C–hot water, D–vacuum, E–u-trap
  3. A–electrodes, B–NH HO3 2+ + CH4 c–steam, d–vacuum, E–u-trap
  4. A–electrodes, B–NH h3 2+ +HO2 + ch4, c–hot steam, D–vacuum, E–u-trap
  5. A–electrodes, B–NH3 + CH4, C–cold water, D–sink, E–u-trap

Answer: 1. A–electrodes, B–NH4+ H2 + HO2 + CH4, C–cold water, D–vacuum, E–u-trap

Question 76. Which one of the following amino acids was not found to be synthesised in Miller’s experiment?

  1. Aspartic acid
  2. Glutamic acid
  3. Alanine
  4. Glycine

Answer: 2. Glutamic acid

Glutamic acid is one of the non-essential amino acids, closely related to glutamine.

It was not synthesised in Miller’s experiment. It is an important metabolic intermediate as well as a neurotransmitter molecule in the central nervous system.

Question 77. In Miller’s experiment, he used a mixture of ch nh h 4 3 2, and water vapour in a closed flask to mimic early earth conditions. What was the temperature at which this flask was kept?

  1. 800°C
  2. 1200°C
  3. 200°C
  4. 400°C

Answer: 1. 800°C

The primitive earth had a high temperature. Therefore Miller kept the mixture in the flask at 800°C to mimic early earth conditions.

NEET practice test on Origin of Life

Question 78. Coacervates were experimentally produced by,

  1. Sydney Fox and pain
  2. Fischer and Huxley
  3. Jacob and Monod
  4. Urey and miller

Answer: 1. Sydney Fox and pain

Oparin and Sydney Fox stated that large organic molecules synthesised abiotically on primitive earth later came together spontaneously and due to intermolecular attraction, formed large colloidal aggregates called coacervates.

Question 79. Which of the following is said to have first evolved on primitive Earth?

  1. Viroids
  2. Coacervates
  3. Cyanobacteria
  4. Mycoplasma

Answer: 2. Coacervates

The large organic molecules, which were synthesised abiotically on the primitive earth later came together due to intermolecular attraction and they formed large colloidal aggregates.

Such water-bound aggregates have been named microspheres by Sydney Fox. Later these colloidal bodies were named coacervates by Oparin.

Question 80. Assertion coacervates are believed to be the precursors of life. Reason (r) coacervates are self-duplicating aggregates of proteins surrounded by a lipid bilayer.

  1. Both a and r are true and r is the correct explanation of a
  2. Both a and r are true, but r is not the correct explanation of a
  3. A is true, but r is false
  4. Both a and r are false

Answer: 3. A is true, but r is false

Coacervates and microspheres are believed to be the precursors of life. The coacervates mainly contain proteins, polysaccharides and some water. Coacervates do not have a lipid bilayer

Question 81. Some complex inorganic and organic compounds in hot sea aggregated in different combinations to form

  1. Protoplasm
  2. Pre-cell
  3. Post cell
  4. Coacervates

Answer: 4. Coacervates

Some complex inorganic and organic compounds in the hot sea were aggregated in different combinations to form coacervates. The term coacervates was given by IA Oparin.

According to him, coacervates are probiotics that are mainly made up
of aggregates of macromolecules (like lipids, carbohydrates, nucleic acids and proteins).

These aggregates remain surrounded by a layer of water which acts as a barrier.

Question 82. Which of the following molecules falls under the category of eobionts?

  1. Coacervates
  2. Microspheres

Choose the right option

  1. Only 1
  2. Only 2
  3. 1 and 2
  4. None of these

Answer: 3. 1 and 2

Eobionts are of two types Coacervates lack membranes, but exhibit some life-like characteristics. They are able to grow and divide.

Microsphere is a non-living collection of organic molecules with double-layered outer boundaries. The term was given by Sydney Fox (1958-1964). So, option 3 is correct

Question 83. Which one of the following is incorrect about the characteristics of protobionts (coacervates and microspheres) as envisaged in the biogenic origin of life?

  1. They were able to reproduce
  2. They could separate combinations of molecules from the surroundings
  3. They were partially isolated from the surroundings
  4. They could maintain an internal environment

Answer: 2. They could separate combinations of molecules from the surroundings

A protobiont is an aggregate of abiotically produced organic molecules surrounded by a membrane.

Protobionts exhibit some of the properties associated with life including simple reproduction, metabolism and excitability as well as the maintenance of an internal chemical environment different from that of their surrounding.

They were partially isolated from the environment, but they could not separate combinations of molecules from the surroundings

Question 84. Coacervates are

  1. Protobionts having polysaccharide + protein + HO2
  2. Protein aggregate
  3. Protein and lipid aggregates
  4. None of the above

Answer: 1. Protobionts having polysaccharide + protein +HO2

The coacervates are a mixture of large proteins and polysaccharides and some water.

Question 85. Coacervates were formed by

  1. Radiations
  2. Polymerisation
  3. Polymerisation and aggregation
  4. Dna

Answer: 3. Polymerisation and aggregation

The coacervates are a mixture of large proteins and polysaccharides and some water. The coacervates were formed by polymerisation and aggregation of proteins.

Question 86. An evolving coacervate-like system would have needed a controlled and constant source of energy for

  1. Making large complex molecules
  2. Organising these molecules into structural patterns
  3. Maintaining their organisation
  4. All of the above

Answer: 4. All of the above

Coacervates require a controlled and constant source of energy for making complex molecules, organising these molecules into structural patterns and maintaining the organisation of these molecules.

Question 87. What is/are true about microspheres?

  1. These are small spherical aggregates of proteinoids
  2. These are considerably stable
  3. These have a double-layered boundary, corresponding to the cell membrane
  4. All of the above

Answer: 4. All of the above

Microspheres are small spherical aggregates of proteinoids. These are considerably stable due to the presence of double layered membrane around them.

Question 88. The heterotroph hypothesis assumes that

  1. A simple organism originated in complex surroundings
  2. A complex organism originated in simple surroundings
  3. Life came from some other planet
  4. Life was created by special creation

Answer: 2. A complex organism originated in simple surroundings

The heterotroph hypothesis assumes that complex evolved slowly from simple non-living matter and this occurred in primitive environmental conditions.

Question 89. The first life that appeared in marine water was called provirus, eobiont or protocell. It was

  1. Anaerobic and chemoheterotrophic
  2. Aerobic and parasitic
  3. Chemoheterotrophic and aerobic
  4. Anaerobic and autotrophic

Answer: 1. Anaerobic and chemoheterotrophic

The first cells evolved about 3900-4000 million years ago in the sea. The atmosphere was anaerobic at that time. Protocells collected more substances and formed cytoplasm.

They became the first living beings. They were prokaryotes and chemoheterotrophs.

Question 90. The reducing environment of the primitive earth was transformed into an oxidising environment by

  1. Photoautotrophs
  2. Chemoautotrophs
  3. Chemoheterotrophs
  4. None of the above

Answer: 1. Photoautotrophs

Early earth’s atmosphere was reducing atmosphere. It contained actively reducing gases such as hydrogen, carbon monoxide and hydrogen sulphide. There was no oxygen in the atmosphere.

As chemical energy gradually reduced, this was proven to be a positive environment for photoautotrophs like cyanobacteria to evolve the photosynthetic metabolic pathways using sunlight as an energy source.

Due to photosynthesis by cyanobacteria, there was a gradual increase in the oxygen level of the earth’s atmosphere. This changed a reducing atmosphere to an oxidising atmosphere. Thus, option 1 is correct.

Question 91. The first formed organism (ribo-organism) used only ………………… For catalysing reactions.

  1. Dna
  2. Amino acids
  3. Fatty acids
  4. RNA

Answer: 4. RNA

Amino acids and fatty acids do not have catalytic properties and hence, options 2 and 3 are incorrect.

Nucleic acids were also formed in a primitive hot soup of the sea. RNA and DNA are the two types of nucleic acid out of which, we know RNA have catalytic properties. Thus, RNA served as enzymes in first life forms.

Question 92. Most biologists think that RNA was the first genetic material because

  1. Amino acids were produced in Stanley Miller’s apparatus
  2. Dna is the universal genetic material of eukaryotes
  3. The existence of ribozymes suggests RNA was used to catalyse chemical reactions
  4. Rna is simpler than dna

Answer: 3. Existence of ribozymes suggests RNA was used to catalyse chemical reactions

Most biologists think that RNA was the first genetic material. This is because rRNA in present-day organisms serves as a catalyst in peptide bond formation during protein synthesis.

The presence of ribozymes (RNA molecules that serve as enzymes) and sequence homology in prokaryotes and eukaryotic rRNA confirm the evolution of their catalytic function earlier during evolution.

Question 93. Biologists believe that the current dna → rna → protein system is the result of evolution because

  1. The steps of ‘DNA → RNA → protein’ consists of many steps
  2. Dna replication is complicated, but relatively error-free
  3. Evidence indicates that RNA preceded dna as the genetic material
  4. All of the above

Answer: 3. Evidence indicates that RNA preceded dna as the genetic material

Biologists believe that the current DNA → RNA → protein system is the result of a long period of evolution because evidence indicates that RNA preceded DNA as the genetic material

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