Which of the following was not found in free form during origin of life :
[CPMT 77, 78, 82]
At a certain point, probably during the great bombardment (of meteorites) some 4.4 Gy ago the Earth had no atmosphere at all - it was too hot and gravity wasn’t strong enough. We know this because our current atmosphere contains very little 36Ar (implying that 99% of the current argon is due to K40 decay). In the Sun, 36Ar is much more common (by a factor of say 10,000). The Earth cooled and icy comets continued to bring water, ammonia, carbon oxides, hydrogen cyanide, formaldehyde and other simple compounds. We can still detect these chemical in space. There was no oxygen gas.
Who gave experimental proof that hydrogen methane water and ammonia gave rise to amino acids :
Survival due to geographic isolation is best exemplified by mammalian fauna of
Oriental region or sino indian biogeographic region,which extend eastward from india to include mainland and much of insolar southern Asia it funna is numerous and highly diverse due to the climate is warm & Temperature has a significant amount of rainfall during year, annual temperature is 16.8ºC .
Primitive atmosphere was made up of the mixture of :
The primitive atmosphere of earth was reducing atmosphere with little or no oxygen but was rich in water vapour, carbon monoxide, carbon dioxide, nitrogen and hydrogen. Thus, oxygen was not present in primitive atmosphere. The high temperature, UV light and lightening provided energy for chemical reactions between hydrogen and free oxygen, nitrogen and carbon to form, ammonia, methane and cyanides. Owing to the high temperature of earth, water was present in form of superheated steam and ammonia, methane and cyanides were present in gaseous form.
Therefore, the correct answer is option C.
According to Oparin, life originated as
According to Oparin life originated in oceans, which acted as hot dilute soup in which life originated from non living aggregates of organic bio-molecules.
There was no life in :
Azoic age were term before 1950 to describe the age of rocks formed before the appearance of life in the geologic sequence. The word azoic is derived from the Greek meaning without and zoon meaning animal, it was first used to mean without death.
Pasteur gave :
Pasteur gave germ theory of disease and he is also known as father of microbiology and discovered microorganism which is known anthrax, bacillus etc.
Life originated :
Origin of earth dates back around 4.6 billion years ago which makes options A and B incorrect as life originated only after the origin of earth. The period of 4.6 billion year ago to 3.8 billion years ago is termed as the Azoic era when the primitive earth conditions were too harsh to sustain any life form. During this period, the earth's temperature cooled down and the ocean and atmosphere were formed. The Archaeozoic era is marked by the appearance of first life form in the hot soup of the primitive ocean which dates back around 4 billion years ago. The first life forms were prokaryotic chemoheterotrophic anaerobic organisms.
Stanley Mille synthesized in his experiment :
DNA is a polymer of :
DNA is a polymer of nucleotide.Nucleotides are the elementary unit that forms DNA. It is made up of three components- nitrogenous base, a pentose sugar, and phosphate. It is formed through phosphorylation of nucleoside. Chain of nucleotides or the polymer of nucleotide is the DNA. It is acidic in nature.
Nucleoproteins gave first sign of :
Huge nucleoprotein were formed by uniting nucleic acids and protein molecules. The particles of nucleoprotein were described as free living genes. Hence, nucleoprotein gave the first sign of life . So, the correct option is a.
What is most important for origin of life
Miller synthesized simple amino-acid from :
Coacervates were experimentally produced by
Coacervates were non living colloidal aggregates of organic molecules. Oparin held that large organic molecules synthesized abiotically on primitive earth latercame together spontaneously and due to intermolecular attraction formed large colloidal aggregates called coacervates.
Who rejected theory of spontaneous generation :
Louis Pasteur's 1859 experiment is widely seen as having settled the question. In summary, Pasteur boiled a meat broth in a flask that had a long neck that curved downward, like a goose. The idea was that the bend in the neck prevented falling particles from reaching the broth, while still allowing the free flow of air. The flask remained free of growth for an extended period. When the flask was turned so that particles could fall down the bends, the broth quickly became clouded . In detail, Pasteur exposed boiled broths to air in vessels that contained a filter to prevent all particles from passing through to the growth medium, and even in vessels with no filter at all, with air being admitted via a long tortuous tube that would not allow dust particles to pass. Nothing grew in the broths unless the flasks were broken open, showing that the living organisms that grew in such broths came from outside, as spores on dust, rather than spontaneously generated within the broth. This was one of the last and most important experiments disproving the theory of spontaneous generation.
Therefore, the correct answer is option B.
Pasteur succeeded in disproving the theory of spontaneous generation because :
The swan neck flask experiment, Pasteur filled a flask with medium, heated it to kill all life and then drew out the neck of the flask into a long S shape. This prevented microorganisms in the air from easily entering the flask, yet allowed some air interchange. If the swan neck was broken, microbes readily entered the flask and grew. Pasteur succeeded in disproving the theory of spontaneous generation by this experiment.
Therefore, the correct answer is option B.
Spallanzani's experiment proved :
In Lazzaro Spallanzani's Experiment: he proved microorganisms could be killed by boiling. He believed microbes move through the air and could be killed by boiling.
Believers of spontaneous generation the believed that :
Spontaneous generation or anomalous generation is an obsolete body of thought on the ordinary formation of living organisms without descent from similar organisms. Typically, the idea was that certain forms such as fleas could arise from inanimate matter such as dust or that maggots could arise from dead flesh. A variant idea was that of equivocal generation, in which species such as tapeworms arose from unrelated living organisms, now understood to be their hosts. Doctrines supporting such processes of generation held that these processes are commonplace and regular. The doctrine of spontaneous generation was coherently synthesized by Aristotle, who compiled and expanded the work of prior natural philosophers and the various ancient explanations of the appearance of organisms, it held sway for two millennia. So, believers of spontaneous generation theory believed that life originated only spontaneously and not originated from similar organisms, from air and from other similar organism or spontaneously.
Therefore, the correct answer is option B.
Life is not found on moon because of :
Now the basis of origin of life is :
Anaximander and Aristotle were main proponents of the theory of spontaneous generation which assumes origin of life from non living substances. It assumes the origin of frogs and toads from mud that of microorganisms from air and so on. Origin of life by God’s desire was refuted by scientific knowledge based upon fossil records and data from comparative anatomy, morphology and embryology.Thus, now life is not originating.
Oxygen in atmosphere has been formed by :
Source of oxygen to the atmosphere is photosynthetic organisms. Photosynthetic organisms, by performing photosynthesis, release oxygen into the atmosphere. So, oxygen in the atmosphere has been formed by Photosynthetic organisms. eg: Green plants, algae, cyanobacteria.
So, the correct option is ‘Photosynthesis of plants’.
Primitive atmosphere was reducing because :
The very first atmosphere of earth was composed mostly of hydrogen atoms and was lost to space because hydrogen is very light gas. The second atmosphere of earth was contributed by gases from earth’s rocky matrix and bombardment of meteorites, it was composed of hydrogen, nitrogen, carbon and water. Hydrogen was the most abundant gas.
Who called large colloidal particles of primitive sea as coacervates :
Who called water of primitive sea as pre biotic soup :
Haldane called the water of the primitive sea as pre biotic soup. According to him,the primordial sea served as a vast chemical laboratory powered by solar energy. Due to the absence of oxygen in the atmosphere, combinations of carbon dioxide, ammonia and ultraviolet radiation lead to the enrichment of organic substances and the sea became a hot dilute soup containing large populations of organic monomers and polymers.
Miller successfully demonstrated formation of amino-acids by electric discharge in the mixture of hydrogen, ammonia, water and
[CPMT 84, 85]
Oparin's theory is based on :
According to Oparin's theory life originated on early earth through physicochemical processes of atoms combining to form molecules, molecules in turn reacting to produce inorganic and organic compounds. Organic compounds interact to produce all types of macromolecules which are organized to form the first living system or cells. Thus according to this theory life originated upon our earth spontaneously from nonliving matter. 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 upon earth. Conditions suitable for the origin of life existed only upon primitive earth.
Which biologist gave most logical biochemical theory of origin of life ?
Alexander Lvanovich Oparin was a Soviet biochemist notable for his theories about the origin of life, and for his book The Origin of Life. He also studied the biochemistry of material processing by plants and enzyme reactions in plant cells. He showed that many food- production processes were based on biocatalysis and developed the foundations for industrial biochemistry in the USSR.
During the course of origin of life what wa the sequence of substances which appeared on earth :
Life cannot originate from inorganic materials at present because :
Oxidising atmosphere is the region that life cannot originate from inorganic materials at present. Today's atmosphere is not conducive to the spontaneous synthesis of complex molecules because the oxygen attacks chemical bonds, extracting electrons. Hence, the correct option is b.
It is believed that the first organisms which inhabitated earth's surface were
[MP PMT 01]