Biology Questions and Answers
- What is the most accepted
hypothesis about the origin of
life on earth? How does it
compare to the other main
hypotheses?
The heterotrophic hystrongest and most acceptepothesis is thed hypothesis (^)
about the origin of life.
The spontaneohas been excluded by the experimeus generation hypothesisnts
of Pasteur. Tis not yet comhe panspermia pletely refuted but it ishypothesis
not well-accepted since it would be
necessary to ecould survive long space xplain how livinjourneys underg beings (^)
conditions of extreme temperatures as
well as to clarifythey would resist the high temperatures the manner by which (^)
faced when entering the earth'satmosphere. The autotrophic hypothesis (^)
is weakened if one takes into account
that thfrom inorganic substances ise production of organic material a highly
complex process requiring diversified
enzymaticexistence o systemsf complex m and that thetabolice
reactions on the primitive earth were
not probable.
- Before the emergence of
life of what gases was the
earth's primitive atmosphere
constituted?
The earth's primitive atmosphere was
basicallyammonia and water formed of methanvapor.e, hydrogen,
- What are the main
constituents of the earth's
atmosphere in our time?
The present atmospconstituted mainly ohere of the earth isf molecular nitrogen (^)
(NNitrogen is the most abundant gas, 2 ) and molecular oxygen (O 2 ). (^)
approximately 80% of the total volume.
Oxygen makes up about 20%. Othgases exist in the atmosphere in a lower (^)
percentage. (Of great concern is the
increase in dioxide due to human activity,the amount of carbon the cause (^)
of the threatening global warming.)
- Was there molecular
oxygen in the earth's primitive
atmosphere? How has that
molecule become abundant?
The presence of molecular primitive atmosphere was probably at aoxygen in the
minimum and extremely rabecame abundant with the emergencere. Oxygen (^)
of photosynthapproximately, 1.etic beings,5 billion (^) years after
the appearance of life on the planet.
- Which physical elements
contributed to the great
amount of available energy on
the primitive earth at the time
of the origin of life?
3.5 billion faster than toyears agday, resulting io the water cycle wasn hard
storms with intense electrical
discharges. Tprotection from thhere was also ne ozone layer o chemicalagainst (^)
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