Which of the following was present in primitive earth?
A
Ammonia and helium
B
Juvenile water vapour
C
Oxygen
✓
Hydrogen and methane
Answer
Correct option: D.
Hydrogen and methane
The primitive earth is thought to be highly reducing in nature due to the absence of oxygen. Hydrogen and methane predominated the atmosphere and caused the condensation of various biomolecules. This theory was forwarded by Oparin and Haldane which accounts for the chemical evolution of life.
It was proved by Urey and Miller through an experimental set$-$up that mimicked the primitive earth conditions and resulted in the formation of amino acids.
Hence, the correct answer is 'Hydrogen and methane'.
The first life on earth evolved in water and evidences indicate that life originated in one of the following eras:
A
Palaeozoic
B
Mesozoic
C
Cenozoic
✓
Proterozoic
Answer
Correct option: D.
Proterozoic
Proterozoic era is the time when life came on earth and there were evidences of life on earth, this includes the formation of cellular structures and less complex organisms.
The first animals to evolve flight were insects. The earliest fossil insects with wings are dragonfly$-$like animals from the Carboniferous, but there are some very fragmentary insect remains from Devonian rocks in Scotland.
The fossils tell that the flight first evolved in insects approximately $410$ million years ago.
Hardy$-$Weinberg equilibrium operates in absence of:
A
Mutation
B
Natural selection
C
Recombination
✓
All of the above
Answer
Correct option: D.
All of the above
The Hardy$-$Weinberg principle states that allele and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolutionary influences.
It operates in the absence of mutation, natural selection, and recombination.
In human evolution, which one of the following is the most recent?
A
Middle Paleolithic
B
Upper Paleolithic
✓
Neolithic
D
Mesolithic
Answer
Correct option: C.
Neolithic
The cultural evolution of man is described in following stages $-$ Palaeolithic, Mesolithic, Neolithic. Neolithic age is the most recent in which man developed agriculture, manufactured pottery and clothes.
Which of the following was the transitional stage $($connective link$)$ between apes and humans?
A
Homo habilis
B
Homo erectus
✓
Australopithecus ramidus
D
Australopithecus africanus
Answer
Correct option: C.
Australopithecus ramidus
Australopithecus ramidus is the most ape like hominid ancestor, who walked upright and is considered to be missing link between hominids and apes. It is the oldest and most primitive of hominin fossil dating back to $4.4$ million years.
Universe originated about $..............$ years ago.
A
$15$ million
✓
$20$ billion
C
$4.5$ billion
D
$3.4$ billion
Answer
Correct option: B.
$20$ billion
The universe is very old and originated about $20$ billion years ago according to Big Bang theory. The universe is the cluster of galaxies which contain stars and clouds of gas and dust.
Igneous rocks are formed from lava and hence no fossil can be found in them. Metamorphic rocks can be made from igneous or sedimentary rocks. Hence, $'a\ ’$ is the correct answer.
Ancestral amphibians were tetrapods that evolved during:
A
Jurassic period
B
Cretaceous period
✓
Devonian period
D
Carboniferous period
Answer
Correct option: C.
Devonian period
Upper $(i.e.$ more recent$)$ Devonian sediments contain fossil remains of salamander$-$like amphibians $($or labyrinthodonts$)$ that were often quite large, with short necks and heavy, muscular tails.
Being all mammals, whale, dolphin, bat, monkey and horse have some common trait, but they also show conspicuous differences. This is due to the phenomenon of:
In $1953 \ S. L.$ Miller created primitive earth conditions in the laboratory and gave experimental evidence for origin of first form of life from preexisting non$-$living organic molecules. The primitive earth conditions created include:
✓
High temperature, volcanic storms, reducing atmosphere containing $\mathrm{CH}_4, \mathrm{NH}_3$ etc.
B
High temperature, volcanic storms, non$-$reducing atmosphere.
The process by which organisms with different evolutionary history evolve similar phenotypic adaptations in response to a common environmental challenge is called:
Under certain conditions scientists have obtained cell$-$like structures. These are known as:
A
Microbes
B
Protists
✓
Coacervates
D
Prebiotic soup
Answer
Correct option: C.
Coacervates
Oparin predicted that cells originated from cell like aggregates of biomolecules formed in hot dilute soup in primitive earth. These early aggregates were called Coacervates.
Being all mammals, whale, dolphins, bat, monkey and horse have some common characters but they also show conspicuous differences. This is due to phenomenon of: