From his experiments, S.L. Miller produced amino acids by mixing the following in a closed flask : 1. CH 3 , H 2 , NH 4 and water vapour at 800 ° C CH3, H2, NH4 and water vapour at 800°C 2. CH 4 , H 2 , NH 3 and water vapour at 600 ° C CH4, H2, NH3 and water vapour at 600°C 3. CH 3 , H 2 , NH 3 and water vapour at 600 ° C CH3, H2, NH3 and water vapour at 600°C 4. CH 4 , H 2 , NH 3 and water vapour at 800 ° C CH4, H2, NH3 and water vapour at 800°C

 

 Question:  100% NCERT covered from Particular Keyword.Explanations are 100% from NCERT | [Difficult level: Easy] From NCERT NEET 2020

From his experiments, S.L. Miller produced amino acids by mixing the following in a closed flask :

1. ${\mathrm{CH}}_3,H_2,{\mathrm{NH}}_4\mathrm{and}\mathrm{water}\mathrm{vapour}\mathrm{at}800°C$

2. ${\mathrm{CH}}_4,H_2,{\mathrm{NH}}_3\mathrm{and}\mathrm{water}\mathrm{vapour}\mathrm{at}600°C$

3. ${\mathrm{CH}}_3,H_2,{\mathrm{NH}}_3\mathrm{and}\mathrm{water}\mathrm{vapour}\mathrm{at}600°C$

4. ${\mathrm{CH}}_4,H_2,{\mathrm{NH}}_3\mathrm{and}\mathrm{water}\mathrm{vapour}\mathrm{at}800°C$

Answer:

4. 

${\mathrm{CH}}_4,H_2,{\mathrm{NH}}_3\mathrm{and}\mathrm{water}\mathrm{vapour}\mathrm{at}800°C$

 

ORIGIN OF LIFE

👉The universe is very

old – almost 20 billion years old.

👉The Big Bang theory attempts

to explain to us the origin of universe.

👉In the solar system of the milky way galaxy, earth

was supposed to have been formed about 4.5 billion years back.

👉There

was no atmosphere on early earth. Water vapour, methane, carbondioxide

and ammonia released from molten mass covered the surface.

👉Life appeared 500

million years after the formation of earth, i.e., almost four billion years back.

👉Early Greek thinkers thought units of life called spores

were transferred to different planets including earth. ‘Panspermia’

👉This was also the theory of spontaneous generation.

👉Spontaneous generation theory was dismissed by louis Pasture

👉Oparin of Russia and Haldane of England proposed that the first form

of life could have come from pre-existing non-living organic molecules

(e.g. RNA, protein, etc.) and that formation of life was preceded by chemical

evolution

👉The conditions on earth were – high temperature, volcanic

storms, reducing atmosphere containing CH4, NH3, etc.

👉In 1953, S.L. Miller,

an American scientist created similar conditions in a laboratory scale

(Figure 7.1). He created electric discharge in a closed flask containing

CH4, H2, NH3 and water vapour at 800°C. He observed formation of amino

acids. 

👉

👉In similar experiments others observed, formation of sugars,

nitrogen bases, pigment and fats.

👉The first non-cellular forms of life could have originated

3 billion years back

👉The first cellular form of life did not possibly originate till about 2000

million years ago.

👉All life forms were in

water environment only.