LIFE AND IT’S ORIGIN
Life is the quality of living substance ,i.e protoplasm .Thus protoplasm is the
physical basis of life .
ORIGIN OF EARTH
• THE EARTH IS PRESUMED TO HAVE ORIGINATED ABOUT 4.5 BILLION
YEAR AGO.
• There are two hypothesis for its origin .
1. Planetesimal hypothesis = it believes that earth is originated as a part
broken off from the molten mass of sun .
NEBULAR HYPOTHESIS
• It is widely accepted hypothesis of origin of earth .
• According to this hypothesis earth is originated by gradual
condensation of intracellular dust or cosmic dust called nebula.
• Cosmic dust consisted of neutron ,proton and electron like particles
• The cosmic material exploded to form numerous pieces called nebula
.the explosion of cosmic material was called big –bang so called big
bang theory .
NEBULAR HYPOTHESIS
According to nebular hypothesis in the
begning ,it was a spinning ball of hot gases
and vapours of elements.butdue to gradual
cooling these gases condensed into solid
form and stratified according to their density
.
The element like heavy metals nickel ,iron
,zinc etc.,sank to the centre of core .
Lighter elements like Al,Si,S etc,formed
mantle and crust of earth .
The lightest and gaseous substance like
H2,He ,C,N, and O2 formed atmosphere .
Theories of origin of life
VON Helmont (1577-1644)
Biogenesis theory
BIOCHEMICAL ORGIN OF LIFE
• It is an evidence in support of biochemical origin of life given by
Oparin and Haldane .Stanley Miller and Harold Uray performed an
experiment in 1953 to test hypothesis of biochemical origin of life
given by Oparin and Haldane ,hence called Miller Urey experiment.
• Mixture of gas
• CH4:NH3:H2 =2:1:2
• And water
LEONARDO DA VINCI
SCHOLARSHIP ENTRANCE QUESTION
1. THEORY OF SPONTAIOUS GENERATION ( ABIOGENESIS ) WAS PROPOSED
BY
• A. Thomson b. redi c. Helmont d. Haldane
2. ACCORDING TO THE THEORY OF BIOGENESIS LIFE IS ORIGINATED FFROM
• A. nonliving things b. chemicals c. preexisting d. both a and c
3 WHAT IS THE BASIS OF LIFE
• A. amino acid b. nucleic acid c. carbohydrates d. fatty acids
4. EXPERIMENT TO PROVE THAT SYNTHESIS OF ORGANIC COMPOUNDS
FORMED THE BASIS OF LIFE WAS PERFORMED BY
• A. oparin and Haldane b miller and urey c. syndex fox d.louis pasture
5.Drawin DEFINED EVOLUTION AS
• A. Continuous change b. diversification c. descend with modification
• D.irreversible change
6 THEORY OF SPONTANIOUS GENERATION STATED THAT:
• A.life arose from living forms only
• B. life arose from both living and non living
• C. life can arise from nonliving things only
• D. life arise simultaneously neither from living nor from the nonliving
• 7 mixture of CH4,NH3,AND H2 ,INSIDE THE TUBE IN SIMULATING EXPERMENT
ARE IN THE RATION
• A.2:2:1 b. 2:1:2 c. 1:2:2 d. 1:1:2
• 8. asper oparin ,the early atmosphere of the earth contained
• A. NH3,N2,H2O b. NH3,N2,HCN,H2O c. NH3,CH4,H2,H2O d. CH4,HCN,H2O
• 9. non functional organ of ancestor become functional in descendants is
called
• A. variation b.mutation c. inheritance d. atavism
• 10. father of palaeontology if
• A. Leonardo da vinci b. George cuvier c. errasmus Darwin d.
Empedocles