Evolution NCERT Flashcards
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 ______.
Origin of life
Huge _______________ comprises the universe.
Clusters of galaxies
_______ theory talks of a singular huge explosion unimaginable in physical terms.
Big Bang theory
Origin of universe is explained by __________ theory
Big Bang theory
How many billion years back the earth was formed?
About 4.5 billion years back
Name 4 gases which were released from molten mass covered surface
Water vapour, methane, carbon dioxide and ammonia
The ____________ from the sun broke up water into Hydrogen and Oxygen
UV rays
Early Greek thinkers thought life came in the form of units from outer space called?
Spores
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.)
Diverse organic molecules are formed from ________________
inorganic constituents
What were the conditions of early earth?
high temperature, volcanic storms, reducing atmosphere containing CH4, NH3, etc.
Who proposed the theory of chemical evolution?
Oparin of Russia and Haldane of England
Who provided an experimental proof for chemical evolution of life in 1953?
S.L. Miller
The first non-cellular forms of life could have originated ____________ years back
3 billion
___________ are remains of hard parts of life-forms found in rocks.
Fossils
Different-aged rock sediments contain?
fossils of different life forms (who probably died during the formation of the particular sediment).
A study of fossils in different sedimentary layers indicates?
The geological period in which these life forms existed
The study of fossils show evidence for evolution. These evidence are called?
Paleontological evidence
A technique which is used to find the age of a fossil is called?
Radioactive-dating
______________________ for evolution was proposed by Ernst Heckel.
Embryological support
Embryological support for evolution was based upon the observation of -
Certain features during embryonic stage common to all vertebrates that are absent in adult
______________ and ________________ shows similarities and differences among organisms of today and those that existed years ago.
Comparative anatomy and morphology
Whales, bats, Cheetah and human (all mammals) share similarities in the _________________ of forelimbs.
Pattern of bones
_______________ structures perform different functions but they have similar anatomical structure.
Homologous structures