Origin of Life Questions in English

(B) Galaxies are massive systems consisting of stars,stellar remnants,interstellar gas,dust,and dark matter,all bound together by gravity. According to the study of the origin of life and the universe,galaxies are primarily composed of vast clouds of gas (mostly hydrogen and helium) and dust,along with billions of stars. Therefore,option $B$ is the correct answer.

(D) The theory of $Panspermia$ suggests that life exists throughout the Universe and is distributed by space dust,meteoroids,asteroids,comets,or planetoids.
Some astronomers still consider this a favorite idea,proposing that units of life called spores were transferred to different planets,including Earth,from outer space.

(A) Stanley Miller conducted an experiment in $1953$ to simulate the conditions of the primitive Earth.
He used a closed flask containing a mixture of gases: methane $(CH_4)$,ammonia $(NH_3)$,hydrogen $(H_2)$,and water vapor $(H_2O)$.
He provided energy for the chemical reactions using electric discharges (electrodes) and boiling water to create steam.
He used a condenser to cool the gases and collect the resulting organic compounds.
Miller did not use $CO_2$ or $O_2$ in his experiment because the primitive atmosphere was considered to be reducing,not oxidizing.

(C) According to the evolutionary history of life on Earth,plants were the first organisms to colonize land. Before animals could move onto land,plants had already established themselves,providing the necessary food and oxygen-rich environment for subsequent animal life. This transition occurred during the Ordovician period,long before amphibians or reptiles evolved.

(D) Louis Pasteur successfully demonstrated the theory of biogenesis,which states that life originates only from pre-existing life.
He performed a famous experiment using swan-necked flasks to show that in sterilized flasks,life did not arise from killed yeast,while in flasks exposed to air,new organisms appeared.
This experiment effectively disproved the theory of spontaneous generation.

(C) Abiogenesis,also known as spontaneous generation,is the theory that life originated from non-living matter.
It suggests that under specific conditions,simple organic molecules could assemble into complex structures capable of self-replication,eventually leading to the first living cells.
Therefore,the correct definition is the origin of life from non-living matter.

(C) The theory of chemical evolution,also known as the Oparin-Haldane theory,proposes that life originated from non-living organic molecules through a series of chemical reactions in the primitive atmosphere. Alexander Oparin and $J$.$B$.$S$. Haldane independently 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. Therefore,the correct answer is Oparin.

(D) Oparin and Haldane proposed the theory of chemical evolution for the origin of life.
According to this theory,life originated from non-living organic molecules through a series of chemical reactions in the primitive atmosphere.
Therefore,$A$ refers to chemical evolution,and $B$ refers to Oparin and Haldane.

(B) According to the Oparin-Haldane theory of the origin of life,the process began with the formation of simple inorganic molecules in the primitive atmosphere.
These inorganic molecules reacted to form simple organic compounds (monomers like amino acids and sugars).
These monomers polymerized to form complex organic compounds,which aggregated to form colloidal structures known as coacervates or microspheres (colloidal aggregates).
These aggregates eventually developed into primitive self-replicating structures called pre-cells or eobionts.
Finally,these evolved into the first true living cells.
Therefore,the correct sequence is: Inorganic materials $\rightarrow$ Organic materials $\rightarrow$ Colloidal aggregates $\rightarrow$ Pre-cell $\rightarrow$ Cell.

(B) According to the Oparin-Haldane hypothesis and current biological consensus,the first life forms on Earth were anaerobic chemoheterotrophs.
These organisms obtained energy by consuming organic molecules present in the 'primordial soup' of the early ocean,as they lacked the complex machinery for photosynthesis or chemosynthesis at that stage.

(C) According to the Oparin-Haldane hypothesis,the early atmosphere of the Earth was a reducing atmosphere. It contained gases like $CH_4$,$NH_3$,$H_2$,and water vapor,but it lacked free molecular oxygen $(O_2)$. Oxygen was produced later through the process of photosynthesis by cyanobacteria.

(B) According to the Oparin-Haldane hypothesis and the chemical evolution theory,the first life forms on Earth were simple,anaerobic,and heterotrophic organisms. These organisms obtained their energy by consuming organic molecules present in the 'primordial soup' of the primitive ocean. Since they relied on external organic sources for energy and carbon,they are classified as chemoheterotrophs. Autotrophs evolved much later after the depletion of organic molecules.

(B) According to the Oparin-Haldane hypothesis,the origin of life occurred through chemical evolution.
$1$. Simple inorganic molecules like water,ammonia,and methane were present in the primitive atmosphere.
$2$. These reacted to form simple organic compounds like amino acids.
$3$. These simple organic compounds polymerized to form complex macromolecules like proteins and nucleic acids.
$4$. Therefore,the sequence is: Ammonia (simple inorganic/organic precursor) $\rightarrow$ Amino acids $\rightarrow$ Proteins $\rightarrow$ Nucleic acids.

(B) According to the Oparin-Haldane hypothesis,the primitive atmosphere of the Earth was a reducing atmosphere.
It contained gases like methane $(CH_4)$,ammonia $(NH_3)$,hydrogen $(H_2)$,and water vapor $(H_2O)$.
Free oxygen $(O_2)$ was absent in the early atmosphere because it was highly reactive and would have immediately combined with other elements to form oxides.
Therefore,the correct option is $B$.

(D) The experiment described in option $D$ is based on the work of $Francesco$ $Redi$ and later $Louis$ $Pasteur$.
By boiling meat broth or meat in a sealed container,the heat kills any pre-existing microorganisms,and the seal prevents new ones from entering.
Since no life appeared in the sealed,boiled container,it provided strong evidence against the theory of 'Spontaneous Generation' (Abiogenesis),which claimed that life could arise from non-living matter.

(D) The concept of chemical evolution,often referred to as the $Oparin-Haldane$ hypothesis,suggests that life originated from non-living organic molecules.
This theory proposes that in the primitive atmosphere of the Earth,which was reducing in nature,simple inorganic molecules combined to form complex organic compounds.
These reactions were driven by energy sources like lightning,volcanic activity,and ultraviolet radiation under specific environmental conditions.
Therefore,the core idea is the possibility of the origin of life through the chemical combination of molecules under suitable environmental conditions.

(A) Protobionts,such as coacervates and microspheres,are considered the precursors to the first living cells. Their characteristics include:
$1$. They are partially separated from their surroundings by a membrane-like boundary.
$2$. They can maintain an internal environment different from their surroundings.
$3$. They can exhibit a simple form of metabolism.
However,they lack the ability to reproduce or replicate their genetic material independently,which is a fundamental characteristic of true living organisms. Therefore,the statement that they are capable of reproduction is incorrect.

(C) The origin of life,according to the chemical evolution theory (Oparin-Haldane hypothesis),follows a specific sequence:
$1$. Synthesis of organic monomers $(II)$: Simple organic molecules like amino acids and nucleotides were formed from inorganic precursors.
$2$. Synthesis of organic polymers $(III)$: These monomers polymerized to form complex molecules like proteins and nucleic acids.
$3$. Formation of protobionts $(I)$: These polymers aggregated to form membrane-bound structures called protobionts.
$4$. Development of $DNA$-based genetic systems $(IV)$: Finally,these protobionts developed self-replicating genetic material ($DNA$ or $RNA$) to become the first living cells.
Therefore,the correct sequence is $II, III, I, IV$.

(B) Statement $(a)$ is correct: The earliest life forms on Earth were anaerobic heterotrophs that lived in an environment lacking free oxygen and chlorophyll.
Statement $(b)$ is correct: The first autotrophs were chemosynthetic bacteria that utilized inorganic chemical energy to synthesize food,and they did not release oxygen as a byproduct,unlike later photosynthetic organisms.
Therefore,both statements $(a)$ and $(b)$ are correct.

(A) In Miller's experiment,the components are labeled as follows:
$A$ represents the electrodes used to create an electric discharge to simulate lightning.
$B$ represents the mixture of gases used,which were $CH_4$,$NH_3$,$H_2$,and water vapor $(H_2O)$.
$C$ represents the condenser,which uses cold water to cool the gases.
$D$ represents the vacuum pump connection.
$E$ represents the $U$-trap,where the condensed liquid is collected.
Therefore,the correct combination is $A-$ electrodes,$B-NH_3 + H_2 + H_2O + CH_4$,$C-$ cold water,$D-$ vacuum,$E-U$ trap.

(C) The Assertion is correct because the origin of life occurred billions of years ago,and the geological processes,such as plate tectonics,erosion,and climatic changes,have destroyed most of the direct evidence (fossils or transitional forms) from that era.
The Reason is incorrect because the loss of evidence is a natural geological and environmental phenomenon,not a result of human negligence or lack of skill in preservation.

(C) Coacervates are large colloidal aggregates formed due to intermolecular attraction from large organic molecules synthesized abiotically on primitive earth.
They mainly consist of proteins,polysaccharides,and water.
While they were once suggested to be potential precursors of life due to their ability to segregate organic molecules,they do not possess the ability to self-duplicate.
Coacervates lack a lipid outer membrane and genetic material,which are essential for reproduction and self-duplication.
Therefore,the Assertion is considered correct in the context of historical scientific hypotheses,but the Reason is incorrect because coacervates are not self-duplicating.

(A) The earliest organisms that appeared on the earth were heterotrophic because of the reducing atmosphere,and the first autotrophs were chemoautotrophs.
An anaerobic organism does not require oxygen for growth and may even die in its presence. Chemoautotrophs were the first autotrophic organisms to appear on Earth,obtaining energy by the oxidation of inorganic molecules in their environment. These organisms did not release oxygen as a byproduct of their metabolic processes. Therefore,both the Assertion and the Reason are correct,and the Reason provides a valid explanation for the nature of the earliest organisms.

(C) The primitive atmosphere was composed of light atoms like hydrogen,which were highly reactive. These hydrogen atoms combined with all available oxygen atoms to form water $(H_2O)$,leaving no free oxygen in the atmosphere. Therefore,the primitive atmosphere was reducing in nature.
The formation of the ozone layer $(O_3)$ is a result of the modern oxidizing atmosphere,which contains abundant free oxygen produced by photosynthetic organisms. In the primitive atmosphere,there was no free oxygen available to form ozone. Thus,the Reason is incorrect.

(B) The Assertion is correct because,according to the Oparin-Haldane hypothesis,the first organic molecules synthesized in the primitive atmosphere and oceans were simple monomers like amino acids and nucleotides,which polymerized to form proteins and nucleic acids.
The Reason is also correct because the early life forms (protobionts) originated and evolved in the primitive aquatic environment (the 'primordial soup').
However,the fact that life originated in water is not the direct scientific explanation for why proteins and nucleic acids were the specific organic compounds required for the origin of life. Therefore,the Reason does not explain the Assertion.

(A) Evolution is the sequence of gradual changes from simple life forms to complex life forms,i.e.,from primitive organisms that lived over millions of years ago to new organisms that exist today.
Human beings are the most recent and most highly evolved among these organisms. To understand these changes,we must know how the origin of life,i.e.,the evolution of the Earth,stars,and in fact the whole universe,took place.
The study of these processes and the history of life forms on Earth is known as evolutionary biology.

(N/A) The universe is approximately $20$ billion years old. It contains huge clusters of galaxies. Galaxies contain stars and clouds of gas and dust. Considering the size of the universe,the earth is indeed a speck.
The Big Bang theory attempts to explain to us the origin of the universe. It suggests that a singular huge explosion occurred,which is unimaginable in physical terms.
The universe expanded and hence,the temperatures came down. Hydrogen and helium formed sometime later. The gases condensed under gravitation and formed the galaxies of the present-day universe. In the solar system of the Milky Way galaxy,earth was supposed to have been formed $4.5$ billion years back.

(N/A) Initially,there was no atmosphere on Earth. Water vapor,methane,carbon dioxide,and ammonia were released from molten masses and covered the surface. $UV$ rays from the sun broke down water into hydrogen and oxygen,and the lighter $H_2$ gas escaped. Oxygen combined with ammonia and methane to form water,carbon dioxide,and other compounds. The ozone layer was formed. As the Earth cooled,water vapor fell as rain,filling the depressions on the Earth's surface to form oceans. Life appeared on Earth approximately $500$ million years after the formation of the Earth,i.e.,about $4$ billion years ago.

(D) Early Greek thinkers believed that units of life called $spores$ were transferred to different planets,including Earth.
'Panspermia' is still a favorite idea for some astronomers.
For a long time,it was also believed that life came out of decaying and rotting matter like straw and mud. This was the theory of 'Spontaneous Generation'.
Louis Pasteur carefully experimented and demonstrated that life comes only from pre-existing life. He showed that in pre-sterilized flasks,life did not come from killed yeast,while in another flask open to air,new living organisms arose from killed yeast. Spontaneous generation was dismissed once and for all.

(N/A) The Oparin-Haldane theory suggests that life originated from pre-existing non-living organic molecules (e.g.,$RNA$,proteins,etc.).
Life formed after chemical evolution,meaning that organic compounds were synthesized from the aggregation of inorganic molecules.
At that time,the conditions on Earth were characterized by very high temperatures,volcanic storms,and a reducing atmosphere containing gases like methane $(CH_4)$,ammonia $(NH_3)$,and water vapor $(H_2O)$.

(N/A) In $1953$,an American scientist named $S$. $L$. Miller created conditions in a laboratory similar to the primitive atmosphere of the Earth. He mixed $CH_4, H_2, NH_3$,and water vapor in a closed flask at $800\,^oC$ and created an electric discharge using electrodes.
He observed that amino acids were formed in the mixture. Similar results were observed in experiments conducted by other scientists,where sugars,nitrogen bases,pigments,and fats were also formed.
Analysis of meteorites falling on Earth also reveals the presence of such compounds,suggesting that similar processes might be occurring in space. With such limited evidence,the theory of chemical evolution is accepted to a greater or lesser extent as the primary hypothesis.

(N/A) In $1953$,$S$. $L$. Miller,an American scientist,created conditions in a laboratory that were similar to the primitive atmosphere of the Earth (see diagram).
He created an electric discharge in a closed flask containing $CH_4, H_2, NH_3$ and water vapor at $800\,^oC$.
He observed that amino acids were formed in the mixture.
Similar experiments by other scientists also showed the formation of sugars,nitrogen bases,pigments,and fats.
Analysis of meteorites falling on Earth also reveals similar compounds,indicating that similar processes might be occurring elsewhere in space.
With such limited evidence,the theory of chemical evolution is more or less accepted as the first concept of the origin of life.

(C) We do not know how the first self-replicating metabolic capsules of life originated. It is believed that the first non-cellular form of life could have originated $3$ billion years ago.
These would have been giant molecules ($RNA$,proteins,polysaccharides,etc.). These capsules likely reproduced themselves. The first cellular form of life did not evolve until about $2000$ million years ago. These were probably single-celled.
All life forms were in the water environment only. Thus,it is generally accepted that the first living cell came into existence through a slow evolutionary process from non-living molecules,as per the theory of biogenesis.

(N/A) The theory of chemical evolution,also known as the Oparin-Haldane hypothesis,is the most widely accepted because it provides a logical,step-by-step scientific framework for the transition from non-living matter to living organisms.
$1$. It proposes that life originated from pre-existing non-living organic molecules (e.g.,$RNA$,proteins,amino acids) through a series of chemical reactions in the primitive atmosphere.
$2$. This theory is supported by the Miller-Urey experiment,which demonstrated that simple organic compounds could be synthesized from inorganic precursors under conditions simulating the early Earth's atmosphere (high temperature,volcanic activity,and reducing atmosphere).
$3$. Unlike other theories (such as panspermia or special creation),it relies on testable physical and chemical laws rather than supernatural or unproven mechanisms.

(A) Louis Pasteur $(1860)$ performed experiments using swan-necked flasks to reject the theory of spontaneous generation (abiogenesis). He demonstrated that life arises only from pre-existing life.
Oparin and Haldane proposed the theory of chemical evolution. According to them,the first form of life originated from pre-existing non-living organic molecules (like $RNA$,proteins,etc.) through a series of chemical reactions in the primitive atmosphere.

(B) In $1953$,Stanley Miller and Harold Urey performed a landmark experiment to demonstrate the chemical origin of life.
They simulated the conditions of the primitive Earth in a laboratory setting.
They used a mixture of $CH_{4}$,$NH_{3}$,$H_{2}$,and water vapour $(H_{2}O)$ in a closed flask.
They provided energy for the reaction using electrical discharges (simulating lightning) at $80^{\circ}C$.
This experiment successfully produced complex organic compounds like amino acids,providing experimental evidence for the Oparin-Haldane hypothesis.

(N/A) Louis Pasteur's experiments successfully disproved the theory of spontaneous generation,demonstrating that life arises only from pre-existing life (Biogenesis).
However,this statement applies to modern biological life. To explain the origin of the first life forms,we must consider the theory of chemical evolution proposed by Oparin and Haldane.
They suggested that the first forms of life could have originated from pre-existing non-living organic molecules (e.g.,$RNA$,$proteins$,etc.) through a process of chemical evolution.
Therefore,the origin of life was preceded by the formation of diverse organic molecules from inorganic constituents in the primitive atmosphere.

(B) Nascent oxygen is highly reactive.
It can react readily with different kinds of molecules,including $DNA$ and proteins present in the cells of aerobic life forms.
This interaction can lead to mutations,damage to cellular structures,and undesirable metabolic changes.
Therefore,in the evolutionary trend,oxygen is considered to be the first major toxic pollutant for early life forms.

(N/A) Evolutionary Biology is the study of the history of life forms on Earth.
To understand the changes in flora and fauna that have occurred over millions of years on Earth,we must have an understanding of the context of the origin of life,i.e.,the evolution of Earth,of stars,and indeed of the universe itself.
It encompasses the study of the origin of life and the evolution of life forms or biodiversity on planet Earth,viewed against the background of the evolution of the universe.

(N/A) The origin of life on Earth occurred millions of years ago,and the study of the history of life forms on Earth is called evolutionary biology.
The history of life comprises two events: firstly,the origin of life,and secondly,the mechanism involved in the changes of living organisms through time,or the evolution of life.
The origin of life is considered a unique event in the history of the universe.
Origin of the universe: The universe is about $15-20$ billion years old.
It comprises huge clusters of galaxies,which contain stars and clouds of gas and dust.
According to the Big Bang theory proposed by Abbe Lemaitre $(1931)$,our universe arose as a cataclysmic eruption.
The temperature lowered,and gases like hydrogen and helium were formed sometime later.
By the force of gravitation,the gas condensed,and galaxies were formed.
Origin of Earth: Earth is supposed to have been formed about $4.5$ billion years ago in the solar system of our Milky Way galaxy.
Its surface was initially covered with water vapor,methane,carbon dioxide,and ammonia released from molten mass.
Later,water molecules were broken into hydrogen and oxygen by the $UV$ rays of the sun.
The lighter hydrogen gas escaped from the surface,while oxygen combined with other compounds.
Subsequently,the ozone layer was formed.
As the Earth cooled,water vapor fell as rain and filled all depressions to form oceans and other water bodies.

(N/A) Life on Earth appeared $500$ million years after its formation,about $4$ billion years ago.
In order to explain the origin of life on Earth,different theories were proposed by various thinkers and scientists:
$(i)$ Theory of Special Creation: It states that God created life through a divine act; i.e.,the Earth,light,plants,and animals were all created by a supernatural power.
This theory has three connotations: $(a)$ All living organisms or species that we see today were created as such. $(b)$ Diversity has remained the same since creation and will remain the same in the future. $(c)$ The Earth is about $4000$ years old.
$(ii)$ Theory of Panspermia: Proposed by early Greek thinkers,it states that life on Earth arose from spores or panspermia,which arrived from outer space and developed into living forms.
$(iii)$ Theory of Spontaneous Generation: It states that life originated from non-living matter automatically. This theory is also known as the theory of abiogenesis or autobiogenesis. For a long time,it was believed that life emerged from decaying and rotting matter like straw,mud,etc. Louis Pasteur (in $1860$) rejected this theory and demonstrated that life comes from pre-existing life. In his experiment,he kept killed yeast cells in a pre-sterilized flask and another flask exposed to air. Life did not evolve in the former,but new living organisms evolved in the latter flask.
$(iv)$ Theory of Chemical Evolution: This theory was proposed by Oparin and Haldane. According to them,the first form of life came from pre-existing,non-living organic molecules (e.g.,$RNA$,proteins,etc.),and chemical evolution was followed by the formation of life,i.e.,diverse organic molecules were formed from inorganic constituents. The conditions on Earth favoring chemical evolution were high temperature,volcanic storms,and a reducing atmosphere containing $CH_4$,$NH_3$,etc.

(N/A) The theory of abiogenesis,also known as spontaneous generation,suggests that life originated from non-living organic matter through a process of chemical evolution.
In $1953$,Stanley Miller and Harold Urey performed an experiment to demonstrate that ultraviolet radiations or electrical discharges,or a combination of these,can produce complex organic compounds from a mixture of $CH_4$,$NH_3$,$H_2$,and water vapour $(H_2O)$ at $800^{\circ}C$.
Electric discharge was created in a closed flask containing $CH_4$,$NH_3$,and $H_2$ in the ratio $2:1:2$. The conditions were set to mimic the primitive atmosphere in the laboratory.
Miller observed the formation of amino acids. Similar experiments by other scientists also showed the presence of complex molecules like sugars,pigments,nitrogen bases,and fats in the flask.
Thus,the Miller-Urey experiment provided experimental support for the theory of chemical evolution,which is a modern interpretation of abiogenesis. Analysis of meteorite content also revealed similar compounds,indicating that similar processes might be occurring elsewhere in space. With these evidences,the concept of chemical evolution became widely accepted.

(N/A) The first non-cellular life forms originated approximately $3$ billion years ago in the form of giant molecules such as $RNA$,proteins,and polysaccharides enclosed within a self-replicating metabolic capsule.
These capsules eventually developed the ability to reproduce their constituent molecules.
The first cellular form of life originated about $2000$ million years ago.
These were likely single-celled organisms that formed exclusively in an aquatic environment.
The theory of abiogenesis,which suggests that the first life forms arose gradually through evolutionary forces acting on non-living molecules,is widely accepted.
Consequently,once these single cells were formed,they evolved over time into the diverse and complex biodiversity observed today.

(B) In $1953$,$S.L.$ Miller conducted a famous experiment to test the Oparin-Haldane hypothesis regarding the origin of life.
He created a simulated primitive atmosphere in a closed flask containing methane $(CH_{4})$,hydrogen $(H_{2})$,ammonia $(NH_{3})$,and water vapor $(H_{2}O)$.
He maintained the temperature at $800^{\circ}C$ and provided energy through electric discharges to simulate lightning.
As a result of this experiment,he observed the formation of simple amino acids,which are the building blocks of proteins.

(A) In $1953$,$S$.$L$. Miller conducted a famous experiment to test the Oparin-Haldane hypothesis of chemical evolution.
He created a closed system (flask) containing a mixture of methane $(CH_{4})$,hydrogen $(H_{2})$,ammonia $(NH_{3})$,and water vapor $(H_{2}O)$.
He maintained the temperature at $800^{\circ}C$ using electric discharges to simulate lightning.
After a week,he observed the formation of simple amino acids like glycine,alanine,and aspartic acid,which provided experimental evidence for the chemical origin of life.

(N/A) Life cannot originate in the present-day atmosphere due to the following reasons:
$1$. The temperature of the present-day atmosphere is significantly lower than that of the primitive atmosphere,which was essential for the synthesis of complex organic molecules.
$2$. The present-day atmosphere is oxidizing in nature due to the high concentration of free oxygen,whereas the primitive atmosphere was reducing,which favored the formation of organic compounds.

(B) Evolution is the process of unrolling or unfolding of nature that brings about an orderly change from one form or condition to another,resulting in descendants becoming different from their ancestors.
The Theory of Special Creation suggests that all living organisms were created in their present form by some supernatural or divine power,and they have remained unchanged since their inception.

(N/A) $1$. Theory of spontaneous generation (Abiogenesis): This theory suggests that life originated from non-living matter in a spontaneous manner. It was a widely held belief in ancient times that living organisms could arise from decaying organic matter.
$2$. Proteinoids: These are thermal polypeptides synthesized by heating a mixture of amino acids at temperatures ranging from $160^{\circ}C$ to $210^{\circ}C$ for several hours. They are considered potential precursors to the first proteins in prebiotic evolution.

(N/A) The large organic molecules synthesized abiotically on the primitive Earth later aggregated due to intermolecular forces,forming large colloidal structures.
$1$. $Microspheres$: These are water-bound aggregates of macromolecules like proteins,lipids,and nucleic acids,named by $Sydney$ $Fox$. They form stable colloidal units with properties resembling living matter.
$2$. $Coacervates$: These are spherical,membrane-bound droplets of organic polymers (like proteins and polysaccharides) that formed spontaneously in the primitive soup,as proposed by $A.I.$ $Oparin$. They represent a step toward the formation of the first primitive cells.

(N/A) $1$. Evolution: It refers to an orderly change from one form to another over a period of time,leading to the development of complex organisms from simpler ancestral forms.
$2$. Chemical evolution: It refers to the formation of diverse organic molecules from inorganic constituents through a series of chemical reactions,which is considered the first step in the origin of life.