NEET Biology Question Bank - Evolution

40 Evolution
- Origin of life and its theoryes :
- Origin of life of protobiogenesis means, the origin of first life from non-livings on the earth about
3000 million years ago. Different religions have also advocated different ideas regarding the origin of
life.
- Abiogenesis : Different living organisms evolved from mud, soil, meat, organic manure.
- Biogenesis : F. Reddy had proposed this principle in 17th century. According to him biogenesis
means formation of new life from pre existing organisms through reproduction.
- Meteorite Theory : This theory believed in cosmozin, as per it for life formation cosmos came
from other planets and on getting favourable conditions they develped into organisms.
- Theory of Eternity : As per this theory life was there when abiotic components were also present
on earth in its earlier stage. This theory was not accepted by any one.
- Theory of catatrophism : Georges Cuvier proposed this theory. He thought that the universe has been
subjected to catatropes or sudden revolution at different intervals.
- Theory of special creation : There were no evidences for this theory. However, Father Suarez
believed that all elements were created within six days.
- Theory of organic Evolution : As per this theory, the world has been evolved and not been
created. Non living substances have reacted to form organic compounds which developed into
colloidal systems. Simple life was developed from them.
- Oparin-Haldane Hypothesis : Modern biologists strongly believe that life is originated in the re
remote past from interaction of chemical substances. It was formulated by Haeckel, on this basis
theory was develpoed by oparin and Haldane. This theory suggests that life is originated from simple
inorganic substances. These substances might be transformed into a colloidal system to produce life.
(A) Chemical evolution
(1) Origin of Earth : It is now scientifically established that the earth was formed from the sun some
5000 millions years ago. When it was fragmented from the sun, it was a glowing fire containing a
molten mass of gases and vapour of various elements. The temperature was very high about 5000oC
to 6000oC. As the earth was moving away from the sun, it was getting cooled. The heavy elements
like iron, nickel etc. occupied the core of the earth where as the lightest elements like helium, hydrogen,
Oxygen, nitrogen carbon etc. occupied the atmosphere of the earth. The chemical changes
leading to the formation of life is called chemical evolution or molecular evolution of origin of life.
(2) Formation of water, Ammonia and Methane : In lighest elements hydrogen was very active, It
combined with nitrogen to form ammonia (NH3) with Oxygen to form water (H2O), and with carbon
form methane (CH4). As the temperature of the earth was high, ammonia and methane remained as
gases and water as superheated streams.
N2 + 3H2 ® 2NH3
C+2H2 ® CH4
1/2O2+H2 ® H2O
As years passed, the temperature of the earth came down, stream condensed into water and
resulted in rain, but the rain drops were evaporated immediately, this procers was repeated for millions
of years, the surface of the earth became cooled. Water gradually accumulated and this led to the
formation of rivers, streams, lakes, seas and oceans. Compounds like ammonia, methane etc. were
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dissolved in rain water and were accumulated in the sea. Mineral rocks also dissolved leading to the
accumulation of mineral and salts in sea water. The first chemicals formed on the earth were
water, ammonia and methane.
(3) Formation of Micromolecule : In molecular evolution the way of formation of micromolecules. amino
acids, fatty acids, monosaccharides, purines, pyrimidines, adenosine monophosphate (AMP) and
Adenosine diphosphate (ADP) appeared as colloidal droplets in the sea. These were distinct bodies
which did not mix with the surrounding sea water. They were contents of proteins, nucleoproteins and
other organic and inorganic molecules in various ratio. The surface layer of the droplet had the ability
for selective absorption of susbstances from the medium.
(4) Formation of macromolecules : When the micromolecules were formed, they combined in
various ways to form large molecules called macromolecules. This process is called polymerization.
(5) Formation of Nucleic acid / Nucleoproteins : The nucleic acid and proteins combined together
to from nucleoproteins which are very important macromolecules to create a life.
(B) Biological evolution :
(1) Formation of coacervates : When macromolecules were formed they undergo aggregation and
precipitation in the sea . Which led to the formation of organised structures called coacervates. They
were distinct bodies. They contained proteins, nucleopreteins and other organic and inorganic
molecules in various ratios.
(2) Formation of precells or protocells : The protocells were spherical in shape and a double -
layered membrane was present around them. The protocells were heterotrophs; they obtained the
energy formed by the fermentation of organic substances which were dissolved in the sea. Thus the
protocells were anaerobic.
(3) Formation of precells to cells : When DNA-RNA system developed within protocells; they looked
like a bacteria or virus. The DNA acquired the ability for self - duplication and protein synthesis.
Gradually time passed the protocells differentiated into cells.

(1) From how many years ago the origin of first life from non-livings on the earth ?
(A) 3000 million years (B) 3000 Trilion years (C) 300 million years (D) 30,000 million years
(2) What was the characteristic of first living organisan ?
(A) replication (B) nutrition
(C) Adaptition and Biosynthesis (D) all the above
(3) By Whom proposed the theory of biogenesis in 17th centuary ?
(A) Aristotle (B) Halden (C) Cuvier (D) F. Reddy
(4) Who proposed the theory of catarophism ?
(A) Christian suarez (B) Cuvier (C) F. Reddy (D) Millor
(5) Who proposed the theory of special Creation ?
(A) Prayer (B) Aristotle (C) Christian Suarez (D) F. Reddy
(6) "The world has been evolved and not been created; Non living substances have reacted to form organic
compounds which developed into colloidal systems," Find out the theory propose the above statements.
(A) Theory of organic Evolution (B) Substrate base(C) Meteority theory (D) Abiogenesis
(7) Who cleared that interaction of chemical substances initiated origin of life in the past ?
(A) Haldene (B) Operin (C) Haeckel (D) Father suarez
(8) In the beginning how much was the tempreture of the earth ?
(A) 50000C to 60000C (B) 60000C to 70000C (C) 70000C to 80000C (D) 80000C to 90000C
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(9) Which elements are foumd in the core of the Earth ?
(A) Iron (B) Helium (C) Hydrogen (D) Carbon
(10) Which substance first take place in the earth envionment ?
(A) Helium (B) Hydrogen (C) Carbon (D) above three
(11) Which substance found in huge mass in primitive earth ?
(A) Carbon (B) Iron (C) Nickel (D) Phosphrous
(12) Which element is most active in primitive earth ?
(A) Iron (B) Hydrogen (C) Oxygen (D) Carbon
(13) Which compound is first formed in the earth ?
(A) H 2O (B) HCN (C) NH2 (D) A and B
(14) Which chemical is first formed in the earth ?
(A) Ammonia (B) Methane (C) A and B both (D) None of the above
(15) Which is the step before molecular evolution ?
(A) Formation of Micromolecule (B) Origin of life
(C) Formation of Microsubstance (D) Formation of chemicals
(16) Which molecules found free in sea ?
(A) AMP (B) ADP
(C) A and B both (D) None of the above
(17) Which is macromolecule ?
(A) Polysaccharide (B) Nucleo protein (C) Proteins - lipids (D) Above three
(18) Name the phenomenon of micromolecules to macromolecules
(A) Conjugation (B) Polymerization (C) Multiple fission (D) Synthesize
(19) Which substances are found in nucleotide ?
(A) Purine (B) Sugar (C) A and B both (D) None of the above
(20) Which molecule is important to make a life ?
(A) Protein (B) Nucleoprotein (C) carbohydrates (D) Lipid
(21) By the macromolecules with the process of precipitation which structure is formed ?
(A) Microspheres (B) Micromolecule (C) Colloiddrop (D) Coacervates.
(22) Which substances have coacervates ?
(A) Proteins (B) Nucleoproteins
(C) Organic and inorgamic molecules (D) All above
(23) When DNA -RNA system developed in protocells, In which form it was ?
(A) Bacteria (B) Spherical (C) Bilayered (D) None of these
Answers : (1-A), (2-D), (3-D), (4-B), (5-C), (6-A), (7-C), (8-A), (9-A), (10-D), (11-A), (12-B),
(13-A), (14- C), (15-A), (16-C), (17-D), (18-B), (19-C), (20-B), (21-D), (22-D), (23-A)

- Urey’sand Miller’s Experiment : The origin of life by molecular evolution first proposed by
Oparin and Haldane. Urey and miller in their experiment created a condition which was similar of
the primitive earth. The steam was allowed to mix with vapours of ammonia, methane and
hydrogen in a reaction chamber. The mixture was treated with an electric shock by electrodes,
mixture was then allowed to cool in a condensor and liquified; then liquid was collected in another
flask. After weeks of treatment the liquid was analysed by chromatography. The liquid contained
simple organic compounds such as amino acids, hydroxy acids and alophatic acid.
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- Evidences for evolution :
(1) Morphology : The sources of evidenes of evolution from morphology and comparitive anatomy are the
following.
(i) Homologous organs : The organs which are similar in their morphology, anatomy and embryology
but dissimilar in their functions are called homologous organs. The relationship between homologeus
organs is called homology.
eg: The forelimbs of higher vertebrates, The thorn and tendrils of Bougainvillea and cucurbita
respectively.
(ii) Analogous organs : The organs which are superficially similar but anatomically dissimilar doing
similar functions are called analogous organs. Similarity of structures connects with similarity of
function is termed analogy.
eg: wings of insects, birds and bats, fins of fishes and whales.
(iii) Vestigial organs : Vestigial organs are the useless and functionless degenerate structures which are
functional in some other animals or in ancestors.
eg: Vermiform Appendix, Nictitating membrane, Ear muscles, wisdom teeth.
(iv) Connecting Links : The animals exhibiting characters of two adjacent taxonomic groups are called
connecting links.
eg: Peripatus : Connecting link between Annelida and Arthro poda.
Balanoglossus : Connecting link between invertebrates and chordates.
Lung fish : Connecting link between fishes and amphibians.
Archeopterix : Connecting link between reptiles and Aves.
(2) Embryology : The early embryos of all vertebrates are very similar in their appearance. This will be
very clear when embryos of a fish, an amphibian, a reptile, an opposum, a monkey and a man are
arranged side by side.
(3) Physiological Evidence : The studies on physiology and biochemislry prove that the process of
evolution has occured biochemically. The protoplasm which is the basic unit of life has the same
quantitative and qualitative attributes in cell of living organism.
(4) Palaeontological Evidence : The direct evidences of the Process of evolution can be obtained by
comparing fossils of the organisms that lived in the part with the organisms living today. The fossils are
the written documents of evolution.
e.g. Available fossils of mesozoic era of different dinasaurs, were large-sized Lizards, that can be proved.
(24) Who proposed molecular evolution of life ?
(A) Oparin (B) Haldane (C) A and B both (D) None of the above
(25) In which year Urey and Miller and his student proved molecular evolution ?
(A) 1947 (B) 1948 (C) 1951 (D) 1953
(26) Which method of anylysis of experiment by Urey and Miller ?
(A) Chromotography (B) Staining Method (C) Isolation method (D) None of the above
(27) In plant kingdom, sequence of evolution is according to which plants division ?
(A) Thallophyta (B) Bryophyta (C) Pteridophyta (D) All above
(28) Which group is first developed with well developed nucleus in animal kingdom ?
(A) Archeae (B) Protista (C) Monera (D) Eukaryota
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(29) Which type of animals are evolved after protista ?
(A) Multicellular (B) Without tissue (C) A and B both (D) None of the above
(30) In which class monkey, ape and man include ?
(A) Aquatic (B) Mammals (C) Aves (D) Reptiles
(31) Which living organisms evolved first during evolutionary order ?
(A) Amphibians (B) Marine´ (C) reptiles (D) Vertebrates
(32) Which word is proper for the similarity in their morphology anatomy and embryology ?
(A) Analogous (B) Vertigeal (C) Homologous organs (D) None of above
(33) Example of Homologous organs.
(A) Wings of insects, birds and bats (B) The thorn and tendrili of bougainvillea and
cucurbita
(C) The forelimbs of higher vertebrates (D) B and C both
(34) The organs which are superficially similar but anatomically dissimilar doing similar functions are
called ........ .
(A) Analogous organs (B) Homologous organs (C) Vestigial organs (D) none of above
(35) Which of the following example of analogous organs ?
(A) Vermiform Appendix, (B) Nictitating membrane and ear muscles
(C) The thorn and tendrils of Bougainvillea and cucurbita (D) A and B both

Answers : (24-C), (25-D), (26-A), (27-D), (19-C), (20-B), (21-D), (22-D), (23-A), (24-C),
(25-D), (26-A), (27-D), (28-B), (29-C), (30-B), (31-B), (32-C), (33-D), (34-A), (35-B)

(36) The useless and functionless degenerate structures which were functional in some other animals or in
ancestors are called ........ .
(A) Homologous organ (B) Analogous organ (C) Vestigial organ(D) None of the above
(37) Which example is vestigial organ ?
(A) Vemiform appendix (B) Nictitating membare (C) Ear muscles (D) above all three
(38) The animals exhibiting characters of two adjacent taxonomic groups are called ...........
(A) Vestigial organs (B) Analogous organs (C) Connecting link (D) Homologous organs
(39) Connecting link of peripatus X ........ and Y .............
(A) X = Annelida Y = Arthropoda (B) X = Amphibians Y = Annelida
(C) X = Fishes Y = Amphibians (D) X = Chordates Y = Fishes
(40) Which two groups are connected by lungfish.
(A) Annelida and Arthropoda (B) Invertebrate and chordates
(C) Reptiles and fishes (D) Fishes and amphibian
(41) Connecting link of Balanoglossus X = ............. and Y = ............
(A) X = Fishes Y = Amphibians (B) X = Annelida Y = Arthropoda
(C) X = Invertebrates Y = Chordates (D) X = Reptiles Y = Chordates
(42) Which animal is conncting between Reptiles and Aves
(A) Balanoglossus (B) Archeopterix (C) Peripatus (D) Lung fish

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(43) Available fossils of Mesozoic era of different dinosaurs were large sized Lizards, That can be proved
by which evidence ?
(A) Embryology (B) Physiologial evidence (C) Palaeontological Evidence (D) None of the above
Answer : (36-C), (37-D), (38-C), (39-A), (40-D), (41-C), (42-B), (43-C)

- Adaptive Radiation :
Organisms depend on the environment for their survival. Environmental factors are not stable.
They are changing time to time and place to place. Hence organisms also adjust themselves to the
changes of the environment in which they live. This adjustment of the organisms to their environment
is called adaptation. When organisms of the same group occupy different environ ments or habitats,
They develop different Kinds of adaptations. Hence organisms of the same group show different
adaptation in different habitats and this is called adaptive radiation. The law of adaptive radiation was
proposed by osborn.
- Adaptive radiation is nothing but divergence or divergent evolution. It is caused by following.
- (1) Need for food (ii) Need for safety (iii) Need for better breeding grounds (iv) Migration to a new
habitat (v) Absence of enemies (vi) Isolation etc. Adaptive radiation is broadly classified into three types:
- Local Adaptive Branching : It refers to the development of diversification in a largely distributed
population. eg: In Africa, two distinct types of Rhinoceres are found.
(i) One is grazing which lives in openland areas and (ii) second is a browsing type which lives in wooded
areas.
(ii) Continental Adaptive Radiation : It refers to the evolutionary lines occurring in organisms of
particular classes living in a continent.
eg: Australian marsupials, Each marsupial differs from other
(iii) Contemporareous Radiation : It refers to the adaptive radiations in the great zoo-geo graphic
division of the world.
Darwin during his journey went to Galapagos islands. There he observed diversity in small
black birds (finches), later this bird is known as Darwin finches. He observed that these were many
varieties of finches in the same island. He conjectured that the varieties evolved on the island itself
from the original seed - eating finch. Modifications in the beaks of finches according to the habitat and
the avaibility of food. Modifications in the beaks of finches developed according to the habitat and the
availability of food.
- Biological Evolution : The Sequential evolution of an organism is a result of adaptation as per the
requirement. With respect to this different theories were proposed. It abstracts are as follows.
- Lamarckism : Lamarckism is also referred as “Inheritance of acquired characters’. The main
aspects of the principle were as under.
(1) Organisms and their organs are constantly increasing in size
(2) Development of organs is induced and maintained under environmental pressure.
(3) Those organs which are constantly used they also develop constantly. Unused organs become
defunct gradually or degenerate.
(4) Those characters which organism acquires in this way are inherited to their offsprings. Thus, the
development of a charaeters increases or decreases generation to generation
- Drawbacks of Lamarckism :
- The first point is in cases of horse and elephant it is true. But in case of flowering plants it is not true.
- The second point is also not true. eg: The neck of an Giraffe cannot be made longer as per its wish,
more over organs cannot be moulded as per of organism wish
- The third point oppears partially true. Muscles can be developed by constant use loss of limbs, due
to disuse in snakes or weak eyesight in cave-dwellers can be quoted as other examples. But eyes of a
voraceous reader do not become larger or brighter. The heart which beats through out life does not
become bigger.
It is also difficult ot accept that acquired characters get inherited. Hence, Lamarkirm is not accepted.

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- Darwinism : The theory of ‘Natural selection’ Proposed by Darwin is the prime one to explain
evolution of living world. It was proposed in 1859 in his book title ‘Origin of species by means of
Natural selection’. New species originate only from a pre existing one. Darwinism is based on the
following main aspects.
- Large Population : The reproduetive rate in all organism is high, if all the offsprings survive the
Population growth will be unimaginable. If all organisms reproduce and produce a large number of
offsprinsg the world will be flooded by them. This does not happen. The population of all species,
generally remains the same from generation to generation. Diseases, lack of food and other natural
factors are responsible for this.
- Struggle for Existense or for survival : If the resources are limited and the number of organisms
dependent on them is unlimited. it is obvious that all organisms can not get sufficient resources.
Thus a competition for resources amongst organisms of one species becomes inevitable. Such
competition can also be with organisms of another species, if their, requirements are identical. Thus
organisms have to compete for survival, growth and reproduetion.
- Natural selection or survival of the fittest : It is quite obvious that when organisms compete for
specific resource, some may get it and others may not get it or may get in enough quantity. some may
fail or success which depends on the nature. Those who succeed will live longer and reproduce Thus,
their hereditary characters will survive in the next generation.
- Variations : All individual of a species are not alike. These differences in characters amongst individuals
of a species are called variations. Those organisms which can use their environment in the best way
succeed and those cannot do so fail. This phenomenon is called survival of the fittest. In due
course of time, the degree of variations increases so that the organisms become totally isolated
from their parents and constitute a new species.
- Limitatious of Darwinism : The greatest draw back of Darwinism is that it does not explain the
origin of variations; it characters are hereditary; for which genes are responsible If we can explain the
mechanism of inheritance, we can explain the variations in offsprings and their conservation over
generations.
- De Veries theory : De vries theory, is also called ‘ Theory of mutation.’
- New characters, ie new variations in characters appear spontaneously. Such a sudden variation is
called mutation.
- Once formed, a mutation becomes permanent. This would mean that it will appear constantly once it
is formed.
- Mutation occurs simultaneously in a large number of organisms. This occurs frequently. Thus, Chances
of natural setection improve.
- Mutation does not occur in a specific direction. Mutation creates many variations.
- De veries does not believe that evolution is a gradual process.
- Modern concept of Evolution : According to the modern concept, there are five basic factors
involved in the process of biological evolution. These are (i) Gene mutations (ii) Changes in
chromosome structures and number (iii) Genetic recombination (iv) Natural selection and (v)
Reproductive isolation.
Besides these, there two accessory processes (i) migration of individuals from one population
to another and (ii) Hybrization between races, species and related genera, are responsible for biological
evolution.
Some important worker like Dobzhansky; R.A Fisher, J.B.S. Haldane, sewall wright, mayr
and G.L. Stebbins gave their contribution to the modern synthetic theory.
- Mechanism of Evolution : Natural selection, adaptation to habitat, and mutation are the major and
sequencial factors for mechaninsm of evolution.

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(44) For the survival, living organisms depend on ........ .
(A) water (B) environment (C) gene (D) all above
(45) Adaptive Radiation is nothing but divergence or divergent evolution is caused by ........ .
(A) Need for food (B) Isolation (C) Absence of enemies (D) all above three
(46) How many types of adaptive radiation ?
(A) Three (B) Five (C) Four (D) Six
(47) In which bird Darwin observed diversity
(A) Black bird (B) White bird (C) Redbird (D) Yellow bird
(48) De vries theory is also called
(A) Isolation (B) Survival of fittest (C) Theory of mutation (D) Variation
(49) How many factors involved in the process of modern concept of biological evolution ?
(A) 4 (B) 3 (C) 5 (D) 6
(50) The differences in characters amongst individuals of a species are called ........
(A) Natural selection (B) Variation (C) Struggle for existence (D) Recombinant of gene

Answers : (44-B), (45-D), (46-A), (47-A), (48-C), (49-C), (50-B)

- Law of Hardy-Weinberg : They laid the foundation for the development of population genetics.
A clear understanding of Hardy - Weinbery law gains through knowledge of gene pool gene
frequencey.
(i) Genepool : The sum total of genes present in a Mendelian population means gene pool.
(ii) Gene frequency : The ratio of a gene in a gene pool or in a population is called gene frequency.
When the gene frequency of one allele is known, the frequency of ther allele in the population
can be calculated by applying a simple formula. If the gene frequency of M-allele is p and that of m-
allele is q. Then p+q = 1. When q is known, p can be calculated, p = 1-q; similarly, when p is known
q can be calculated; q = 1 - p; for example p is 0.6. Then q = 1 - p = 1 – 0.6 = 0.4.
Practical Application of the law : This formula can be appried to any population to find out the
frequency of genes, Let us apply this formula to a hamster population containing equal number of M
and m genes.
The Freqvency of m gene in population is = 50 % = 1/2
So. q = 1/2 = 0.5
(p + q)2 = p2 + 2pq + q2
= (0.5)2 + 2(0.5)(0.5) + (0.5)2
= 0.25 + 0.5 + 0.25
= 25 %, MM + 5.0 % Mm + 25 % mm

Importante : This law states that the gene frequencies in a large population, remain constant
generation after generation when there is no selection and mutation. In small population this equilibrium
cannot be maintained.
- When the population is in equilibrium there is no possibility of change and hence the rate of evolution is
zero. Evolution occurs only when this equilibrium is upset.

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- Gene flow : Animals are not static. They have the tendency to migrate. When an animal migrate and
comes in contact with another population, it mates with the immate of the population. Thus the genes
of one population or transferred in to another population. This is called geneflow. If genes are carried
to a population, where these genes previously did not exist, this event of geneflow can be very important
source of genetic variation.
- Genetic Drift: Genetic drift is an evolutionary force in small population. This matter was described by
Sewall wright 1931. Hence it is called Sewall wright effect. According to Hardyweinberg law in a large
population the gene frequency remains constant from generation to generation when there is no selection
and mutation. But in small populartion, the gene frequerncies are found to fluctuate purely by chance
This change in the frequency of gene purely by chance is called geneti drift. The effect of genetic drift
is insignificant in large population. But in small population it has a significant effect. As result of this, in
small population, some gene may be reduced in frequency or even lost by chance and other may be
increased in frequency by chance.
- Brief account of Evolution : Earth originated about 500 millions years ago.
- Life in the first form of cell, originated about 3000 millions years ago, some of these cells had the
ability to release O2.
- About 500 million years ago invertebrate were originated.
- sea weeds and few plants existed probably about 320 millions years ago. Fishes originated 360
millions, amphibians 325 million, Reptiles 250 million, Mammals 165 million and First man originated
before 2 million years ago.
- The account of biological evolution and age of different animals will be still more clear if the time of
the origin of life is placed to a 12 hours scale. If it is imagined that life originated at 12.00 midnight,
then fishes appeared at 8.00 pm. amphibians at 8.30 p.m, reptiles appeared at 9.00 pm, mammals
appeared at 10.00 p.m. and man appeared at 1159 pm
Scale :
1 second = 52, 000 yrs, / minute = 3,25,000 yrs 1 hour = 187,5000 yrs.
(51) How many million year ago life have originated ?
(A) 5000 (B) 3000 (C) 4000 (D) 4500
(52) How many millions year ago sea weeds are few plants existed ?
(A) 120 (B) 400 (C) 220 (D) 320
(53) The origin of life is compared to a ..... scale
(A) 13 hours (B) 10 hours(C) 12 hours (D) 14 hours
(54) At what time fishes are appeared
(A) 9:00 PM (B) 8:00 PM (C) 8:00 AM (D) 8:05 PM
(55) In geological clock, 1 miniute is equal to how many years ?
(A) 3,25,000 (B) 52,000 (C) 1,87,000 (D) None of all above
(56) In which year Handy-weinberg law was proposed ?
(A) 1908 (B) 1907 (C) 1808 (D) 1900
(57) What is the importance of Hardy-weinberg law ?
(A) Evolution (B) Gene pool (C) genetics (D) genetic variation
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(58) The sum total of genes present in a mendelian popolation is called ........ .
(A) gene pool (B) gene frequency (C) genetic variation (D) Genetics.
(59) How many years ago the earth was originted ?
(A) 6000 (B) 5500 (C) 5000 (D) 6500

Answers : 51 (B), 52 (D) 53 (C), 54 (B), 55 (A), 56 (A), 57 (A), 58 (A), 59 (C)

- Origin and Evolution of Man : About 480 million years ago our distant ancestors of our order lived
in fresh water ponds in the form of crossopterygian fishes. The other ancestors inthe path of primates
evolution are as under.
Prosimians Anthropoids
[Tree shrew, Lemur, Lorise etc] [Gibbon, Orangutan, Chimpanzee, Gorilla] Monkeys and man]

3 Primates
/
n
Insectivors (Mammals)
n
Theropsid (Raptiles)
n
Cotylosaur (Reptiles)
n
Labyrinthodont (Amphibians)
n
Crossopterygian (Fishes)
- Human Euolutionary Trends: Like other animals, human evolution exhibits directional Progressive
changes, which are summurised below:
The change of arboreal life into terrestrial life is the most important evolutionary trend, Loss of
opposite toes from hind limbs, Development of erect posture, Development of bipedal locomotion,
The development of chin, Increase in the size of brain development of intelligence, Disappearance
of simian shelf, Use of fore limbs for non-locomotory purposes, etc.
- Fossil Record of Man’s Evolution: The gradual evolution of man from ape is fully supported by
available fossils.
(1) Propliopithecus : It was an ape-like primate. But in the possession of short arms, it resembled man.
It lived, about 30 million years ago.
(2) Aegytopithecus : It is similar to proplipithecus; but it is more identical to apes than propliopithecus.
It is believed that it was ancestral of the Dryopithecus. Another view did not support this.
(3) Dryopithecus : It is a group of apes that lived in miocene period, about 20 million years ago. It
decended from Aegytopithecus or propliopithecus. It’s forelimbs were shorter than hindlimbs. In this
respect, it is belived that it is the distant ancestor of man. It is also ancestor of modern apes like
chimpanzee and Gorilla.
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(4) Oreopithecus : In the structure of teeth, small face of and erect walking, it resembles to man, but
having long forelimbs it resembles to apes. Straus (1963) and simpson (1963) Suggest that man
and oreopithecus have parallel evolution and hence it is not ancestral to man.
(5) Ramapithecus : It lived 12 to 14 millons years ago Late miocone and early pliocene. The denitition
is more identical to dentition of man. Fossils of Ramapithecus was collected from India and Africa.
(6) Kenyapithecus : It is closely related to Ramapithecus.Its fossil is collected from East Africa.
(7) Australopithecus : It was 2 to 5 millions years old. The characters of Australopithecus like man and ape.
Man like charactes : Erect posture, Bipedal locomotion, Dentition is like that of man.
Apelike characters : The teeth were larger than modernman, Absence of chin, the eye brow ridges
projected over the eyes.
(8) Homoerectus : Their fossils were collected from java so it is called Java man. Other fossils were
collected from peking in china so, it was commonly called peking man. The Java man and peking man
are similar. They lived about 5,00,000 years ago. It forms connecting link between Aurtralopithecus
and Homo sapiens (Modern man).
Characters : They had upright bipedal locomotion, They were slightly taller than Austrolopithecus.
The face was chinless. They used fire and variety of tools, They inhabited caves. They were hunters.
(9) Homo sapiens : Homo sapiens were descended from Homoerectus. Number of fossils are known as
below.
(i) Neanderthal man : The fossils were collected form the Neanderthal valley of Germany. They
existed about 75,000 years ago and became extinct by 25,000 years ago.
Characters : Their eyebrow ridges were heavy and protruding. They have no chin.Their teeth were
large. They prepared their tools much more skillfully than the pre-previous men. Their
cranial capacity was about 1400cc.
(ii) Rhodesian man: The fossils were collected from Rhodesia the cranial capacity was about
1300 CC.
(iii) Cro-Magnon man : These were the men who lived in Europe during the last 30,000 years.
They possessed almost all characteristics of modern man.
(iv) Modernman : The successors of cro-Magnon man, which originated about 8000 years ago attempted
for food production from plants and domestication of animals led them towards present day civilization. The
cranial capacity of mordern man is 1450 CC.
Man classified different races according to appearance, characters and zoo-geographical distribution.
Main Man subspecies : Caucasiod race, Negroid race Mongoloid race, American race, Indian race.
and Australian race.
(60) How many million years ago our distant ancestors of our order lived in fresh water pond in the form
of crossopterygian fishes ?
(A) 470 million years (B) 500 million years (C) 480 million years (D) 400 million years
(61) How many years ago propliopithecus was lived ?
(A) 30 million (B) 32 million (C) 35 million (D) 40 million
(62) Aegyptopithecus is similar to ........ .
(A) Dryopithecus (B) Oreopithecus (C) Propilopithecus (D) Ramapithecus
(63) From where the fossils of Ramapithecus found ?
(A) India and srilanka (B) India and Africa (C) Pakistan and srilanka
(D) America and Africa.
(64) Whos closely related with kenyapithecus ?
(A) Australopithecus (B) Oreopithecus (C) Ramapithecus (D) Dryopithecus
920

(65) Which characters of Australopithecus is like man
(A) Erect posture (B) inhabited in cave (C) Absence of chin (D) Hunter
(66) How many years ago the java man and peking man was lived ?
(A) 5,00,000 years (B) 3,00,000 years (C) 5,50,000 years (D) 4,00,000 years
(67) From whom Homo sapiens were descended ?
(A) Ramapithecus (B) Kenyapithecus (C) Australopithecus (D) Homo erectus
(68) How many years ago the fossils of Neanderthal man found ?
(A) 75,000 years (B) 70,000 years (C) 76,000 years (D) 60,000 years
(69) From where the fossils of Rhodesion man collected ?
(A) Valley of Germany (B) Rhodesia (C) Australia (D) Iran
(70) When the successors of cro-magnon man originated ?
(A) 7000 year (B) 9000 year (C) 8000 year (D) 8800 year
(71) What is the cranial capacity of modern man ?
(A) 1450CC (B) 1400CC (C) 1500CC (D) 1550CC
(72) How many races of human are found ?
(A) Five (B) Four (C) Six (D) seven
(73) Which is main races of human ?
(A) Erectus (B) Caucasoid (C) Homo sapien (D) Australopithecus
(74) When Neanderthalman extinct ?
(A) 30,000 years ago (B) 35,000 years ago (C) 25,500 years ago (D)25,000 years ago
(75) Which group was decended from aegyptopithecus or propliopithecus ?
(A) Ramapithecus (B) Australopithecus (C) Dryopithecus (D) Oreopithecus
(76) Straus and simpson suggest that X and Y have parallel evolution ?
(A) X = man, Y = Oreopithecus (B) X = Kenyapithecus, Y = Oreopithecus
(C) X = man, Y = Australopithecus (D) X = man, Y = dryopithecus.
(77) What is the cranial capacity of Neanderthalman Rhodisian man and modern man respectively ?
(A) 1450, 1300CC, 1400CC (B) 1400CC, 1300CC, 1450CC
(C) 1300CC, 1400CC, 1450CC (D) 1450CC, 1400CC, 1300CC
Answers : (60-C), (61-A), (62-B), (63-C), (64-C), (65-A), (66-A), (67-D), (68-A), (69-A), (70-C),
(71-A), (72- A), (73-B), (74-D), (75-C), (76-A), (77-B)

· A - Assertion R - Reason
Answer the following questions, by choosing the appropriate option.
(A) A and R both are true and R is a explanation of A.
(B) A and R both are true and R is not a explanation of A.
(C) A is true and R is false
(D) A is false and R is true
921

(78) Assertion A : After the formation of macromolecules they undergo aggregation and
precipitation in the sea
Reason R : The formation of organ structures called coacervates.
(A) (B) (C) (D)
(79) Assertion A : At the end of longtime complicated living organism developed
Reasin R : According to requirement of living organism they change their body organisation.
(A) (B) (C) (D)
(80) Assertion A : Primitive earth have huge mass of hydrogen, Nitrogen, carbon, and oxygen
Reason R : Among them Nitrogen is most active
(A) (B) (C) (D)
(81) Assertion A : Marine invertebrate animals originated
Reason R : Protista originated having developed nucleous.
(A) (B) (C) (D)
(82) Assertion A : If population is in equilibrium
Reason R : The rate of evolution is zero
(A) (B) (C) (D)
(83) Assertion A : Lamarkism is acceptable
Reason R : It is difficult to accept that acquired characters get inherited.
(A) (B) (C) (D)
(84) Assertion A : Mutations occurs simultaneously in a large number of organisms
Reason R : Thus chances of natural setection improve
(A) (B) (C) (D)
(85) Assertion A : The protocells obtained the energy formed by fermentation of organic substance
Reason R : In primitive atamosphere lack of free oxygen.
(A) (B) (C) (D)
(86) Assertion A : Protocell were heterotrophic
Reason R : Protocell were anerobic
(A) (B) (C) (D)
(87) Assertion A : DDT nearly uneffective against moquitoes
Reason R : Continuous consumption of DDT, DDT sensible gene resistance gene become
mutant.
(A) (B) (C) (D)
Answers : (78-B), (79-A), (80-C), (81-D), (82-A), (83-D), (84-A), (85-A), (86-B), (87-A)

˜ Match the column and find out the correct option trom following.
(88) Collumn I Collumn II
(i) Genefic drift (p) The gene frequencies are found (A) (i-q) (ii-r) (iii-p) (iv-s)
(ii) Gene flow to fluctuate purely by chance (B) (i-r) (ii-s) (iii-q) (iv-p)
(iii) Gene frequency (q) The genes of one population are (C) (i-p) (ii-q) (iii-r) (iv-s)
transferred in to another population (D) (i-s) (ii-p) (iii-r) (iv-q)
(iv) Gene pool (r) The ratio of a gene in a gene pool
(s) The sum total of genes present in
a mendelian population.
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(89) Collumn I Collumn II (Connecting link)
(i) Peripatus (p) Invertebrate and chordates (A) (i-r) (ii-s) (iii-q) (iv-p)
(ii) Balanoglossus (q) Fishes and Amphibians (B) (i-p) (ii-r) (iii-q) (iv-s)
(iii) Lung fish (r) Annelida and Arthropoda (C) (i-r) (ii-q) (iii-p) (iv-s)
(iv) Archeopterix (s) Reptiles and Aves (D) (i-r) (ii-p) (iii-q) (iv-s)
(90) Collumn I Collumn II
(i) F.Reddy (p) Theory of catatrophism (A) (i-p) (ii-s) (iii-r) (iv-q)
(ii) Qvier (q) Theory of mutation (B) (i-r) (ii-p) (iii-s) (iv-q)
(iii) S wright (r) Biogenesis (C) (i-s) (ii-r) (iii-p) (iv-q)
(iv) De vries (s) Modern concept of Evolution (D) (i-q) (ii-r) (iii-p) (iv-s)
(91) Collumn I Collumn II
(i) Ramapithecus (p) Java (A) (i-p) (ii-s) (iii-q) (iv-r)
(ii) Kenya pithecus (q) Germany (B) (i-r) (ii-p) (iii-q) (iv-s)
(iii) Homo erectus (r) India and Africa (C) (i-r) (ii-s) (iii-p) (iv-q)
(iv) Neanderthal man (s) East Africa. (D) (i-q) (ii-r) (iii-s) (iv-p)

Answers : (88-C), (89-D), (90-B), (91-C)

· True-Flase (T - F)
Given sentence are true or flase choose appropriate answer.
(92) (i) Coacervates is a free molecules.
(ii) Protocells were heterotrophs.
(iii) Oparin considered the coacervates as the sole living molecules.
(iv) The protocells in course of time differentiated in to cells.
(A) TFTT (B) TTTT (C) FTFT (D) FTTT
(93) According to Lamarkism
(i) Organisms and their organs are constantly increasing in size
(ii) Development of organs is supress under enviornment pressure
(iii) Unused organs become defunct gradually
(iv) These characters which organism acquires in this way are inherited to their of spring.
(A) TFTT (B) TTFT (C) TFTF (D) TFTT
(94) (i) The earth was formed from the sun some 5000 billions year ago.
(ii) The temperature was 3000oC to 4000oC when earth was formed.
(iii) The heavy elements occupied the core of the earth.
(iv) Life originted only from lightest elements
(A) TFTT (B) FTTF (C) FTFF (D) FFTT
(95) (i) Analogous organs : insects, birds
(ii) Vestigial organs : Vermiform Appendix wisdom teeth
(iii) Homologous organs : Man, bird, whale
(iv) Connecting Link : Fishes and Reptiles
(A) TFFT (B) TTFF (C) TTTF (D) TTTT

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(96) According to gene flow
(i) Animal have the tendency to migrate
(ii) Animal not mating with the inmate of the population.
(iii) The gene of one population are not transferred in to another population.
(iv) The event of gene flow can be very important source of genetic variation
(A) TFTT (B) TFFT (C) FFFT (D) TTFT
(97) According to Genetic Drift
(i) In a large population the gene frequency remains constant from generation to generation when
there is selection.
(ii) In small population the gene frequencies are found to stable purely by chance.
(iii) The effect of genetic drift is significant in large population.
(iv) In small population some gene may be increased in frequency
(A) FTFT (B) TFTF (C) FFFT (D) FFFF
(98) (i) The earth was formed some 5000 millon years ago.
(ii) Life originatel about 3000 millions years ago.
(iii) Invertebrate originated about 500 millions years ago
(iv) Sea weed originated about 320 million years ago.
(A) TTFF (B) TTFF (C) TFTT (D) TTTT
(99) Texom and originated in million years.
(i) Fishes - 500 Millon years ago (ii) Amphibian 400 Millon years ago
(iii) Reptiles - 250 Millon years ago (iv) Mammals 165 million years ago
(A) TTFF (B) FFTT (C) TFTF (D) FTFT
(100) According to characters of Homo erectus
(i) They were slightly taller than australopithecus
(ii) The face was chinless
(iii) They prepared their tools much more skillfully than the preprevious men
(iv) They inhabited in caves.
(A) TTFT (B) TFFT (C) FFTT (D) TFTF
(101) According to characters of Neanderthalman
(i) They had chin
(ii) Their teeth were large
(iii) The cranial capacity was about 1300 C.C.
(iv) Their eyebrow ridges were heavy and protruding
(A) FTFF (B) TTFT (C) TFTF (D) FTFT

Answers : (92-B), (93-A), (94-D), (95-C), (96-B), (97-D), (98-D), (99-B), (100-A), (101-D)

924

Electrode
W

Gases
Stopcork X

Water
droplets

Water
Heat

Urey and Miller experiment

(102) Identify the nane of W and X
(A) W - Reaction chamber X - Stopcork (B) W - Condenser X : - Reaction Chamber
(C) W Reaction chamber X : Condensor (D) W condensor X : Stopcork
(103) Give the function of W
(A) To Separate the substanee of mixture X

(B) To help the mixture cold
Y
(C) Path for addition of mixture

(D) The mixture was treated with an electric shock.
Coacervates
(104) Indicate part x in given diagram, which type of absorbing capacity, occur for substances of surface
medium ?
(A) impermeable (B) Permeable (C) Selectivly permeable (D) Non selectively
(105) What is the chemical nature of 'X' organic molecule
(A) Organic molecule (B) Nucleo protein (C) Proteins (D) alll above three
(106) Give the name indicate y
(A) Organic molecule (B) Protocells (C) inorganic molecule (D) Molecular particles

Y X
(107) Give the name of X and Y
(A) X - Archeopterix Y - Balanoglssus (B) X - Balanoglossus Y = Peripatus
(C) X - Peripatus Y -Balanoglossus (D) X - Balanoglossus Y = Archeopterix
(108) Give, the name of connecting link of X and Y
(A) X - fishes and Amphibians Y - invertebratesand chordates
(B) X - Annelida and Arthropoda Y - invertebrates and chordates
(C) X - Invertibrates and chordeaes Y - Annelida and Arthropoda
(D) X - Annelida and Arthropoda Y = fishes and Amphibiam
Answers : 102 (C), 103 (D), 104 (C), 105 (D), 106 (A), 107 (B), 108 (B)

925

l NEET Questions :
(109) Random reproduction remains balanced Which of the following undirectional method brings genetic
fluctuation ?
(A) Migration (B) Genetic drift (C) Mutation (D) Selection
(110) Random genetic drifts in a population are a result of
(A) Small size of population (B) Major genetic differences in individuals
(C) Interspecific hybridization (D) Slower rate of mutation
(111) Which type of evidences shows that Human being is more related to chimpanzee than
man like apes ?
(A) Evidences of DNA of only sex chromosomes
(B) Comparison of chromosomes. - according to Morphology.
(C) Fossils, only mitochondria and DNA and evidences of fossils.
(D) Sex chromosomes, autosomes and DNA taken up from mitochondria
(Hint): Sex chromosomes, Autosomes and mitochondrial DNA shows genomic limitations.
Chromosomal morphology is onesided.
(112) Which of the following is accurate method to decide fossil dating ?
(A) Carbon - dating method (B) Potassium - Argon method
(C) Electron - spin resonence method. (D) Uranium - Lead method.
(Hint): For Fossil dating electron spin resonence method is very appropriate method.
(113) There are two opposing opinions regarding the evolotion of modern man. According to one Homo
erectus is the ancestor of the modern man, Based on genetic differences, The origin of modern man
is African. Based on the DNA studies, what do the differences indicate ?
(A) More differences in Asia as compared to Africa
(B) More differences in Africa as compared to Asia
(C) Similar differences in Africa and Asia.
(D) No differences in Africa, only differences are seen in Asia.
(Hint): According to Neo-Darwinism, Variation is the main cause of evolution.
(114) De- Vris Organic evolution theory of mutation was given after research on ........ ?
(A) Pisum sativum (B) Drosophila melanogaster (C)Oenothera lamarckiana (D) Alicia rosa
(Hint): Pisum sativum - Mendel
Drosophila melanogaster - T.H. Morgan)
(115) Evolutionary History of living being is known as
(A) History of ancestors (B) Fossil study (C) Ontology (D) Phylogeny
(Hint): Study of fossils is known as palaentology.
Ontology is study of embryonic development.
Phylogeny is history of living being evolution.
(116) Which of the following is not living fossil ?
(A) Sphenodon. (B) Archeopterix (C) Peripatus (D) King crab
(Hint): Archeopterix fossil are obtained from meoszoic basins. They were connecting links between
reptiles and Aves.
(117) When species of two different geneology found together as a result of the event known as .....
adaptation.
(A) Homology (B) Mutation (C) Analogy (D) Variation
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(118) Which of the following is a correct statement ?
(A) There is no evidence of gills during the embryonic development of mammals.
(B) All plant and animal cells are totipotent.
(C) Ontogeny recapitulates phylogeny.
(D) Stem cells are special cells.
(Hint): Ontogeny recapitulates phylogeny.
(119) What is common amongst parrot, platypus and knagaroo ?
(A) Teethless jaws (B) Active tail at the posterior end.
(C) Similar egg cell (ovum) (D) Homeothermy.
(Hint) :Only birds and mammals are homeotherms.
(120) Which of the following is the result of geographic isolation ?
(A) Checks speciation (B) Speciation due to reproductive isolation
(C) Random formation of new species (D) No differences in the separated organisms.
(121) Which of the following birds has reptilian ancestors ?
(A) Scales on forelimbs. (B) Four chambered heart
(C) Presence of crop and gizzard in the digestive canal (D) Calcareous Eggs.
(Hint): Calcareous eggs and scales on the hind limbs indicate reptilian ancestors
(122) The thorns on Bougainvilea stem and the tendrils on cucurbita are examples of ........ .
(A) Analogous organ (B) Homologous (C) Vestigeal organ (D) Regression
(Hint): Thorns of Bougainvillea. and tendrils of cucurbita are homologous organs.
(123) Which is the most important factor for the evolution of modern man from his ancestors ?
(A) Erect posture (B) Narrowing of jaws (C) Bifocal three dimensional vision.
(D) Increase in cranial eapacity.
(Hint): Increase in brain capacity is the main factor for the evolution of modren man.
(124) In a given region; the evolution of species from a point to different geographic regions, is called as
(A) Contemporareous Radiation (B) Natural selection (C) Radiation (D) Divergent evolution.
(Hint): The process of speciation is a given region from a point to different biogeographic regions is
contemporaneous radiation process. For Example : Darwin's Finches, Australian Marsupials.

Answers : (109-B), (110-A), (111-D), (112-A), (113-A), (114-C), (115-D), (116-B), (117-C), (118-C),
(119-D), (120-B), (121-D), (122-B), (123-D), (124-A)

927

Origin of Life
¯
¯ ¯
Theories of origin of unitvers Chemical Theory of orogin of lice
¯
® Nebular Hypotbesis
• Oparin- Haldane's of chemical origin theory is most
It was propsed by Kant-Leplace widely accepted theory of origin of life. It involves some
according to which earth basic stpes that are :
originated about 4.5-5 billion • Formation of inorganic molecules
years ago from a gaseous cloud • From the gases present in early earth's atmosphere.
solar nebula. • Formation of simple organic compounds
• From the inorganic compounds formed in previous step.
• Spontaneous formation of complex organic molecules
• Simple organic molecules combined to from large organic
Big bang Theory
® complex biomolecules like starch, proteins, fatty acids.
• Spontaenous formation of molecular aggregates,
According to this theory of concervates, eobionts and first living cell
Abbe Lemaitre univers formed • Complex organic compounds synthesized on primise
by a big bang (thermonuclear earth grouned togeths spontaneously and due to intermo-
expansion) of a dense entilty. lecular attraction formed large colloidal aggregates called
coacervates or Micropheres which tuned into eobionts
(controlled by nucleic acids). These developed cel mem-
brane and formed first living cells or prokayotes.

¯
Eukaryotes (Unicellular)

l

928

Evolution
(Latin evolvere-to unroll) Multicellular organisms
evolved from tiny eukayryotic unicellular ones.

¯ ¯ ¯
Evidence of evolution Theories of evolutions Mechanism of evolution
®
Morphological and Evolution starts with gen-
® Lamark's Theory
anatomical eration of variations,
It says that "The changes in
Comparaive studies of morphol- Variations in a population
structure or function of any may occur by mutations,
ogy and anatomy, homology of
organ are acquired during the genetic drift, gene migra-
organisms provide evolutionary
proofs, e.g. vestigial organs, ata- lifetime of an individual by tion, hybridization, etc.
vism etc. use of disuse of that organ Out of these variations in-
and are inherited" causing heritable variations un-
® Embryological evolution. dergo natural selection
and the individual with
Comparative study of embry- ® Darwain's Theory highest survival value in
onic development of various
the present environmental
organisms shows various simi- It says that variation occur in
conditions evolve.
larities and resemblance to organisms and useful amoung
embryos of lower organisms them are selected by nature
indicating evolution (Biogenetic (i.e., natural selection) and get
law of Haeckel) accumulated in the organism.
This leads to evolution.
® Pateontological ® Human evolution
Paleontology is the study of All human beings present
fossils (preserved remains of ® today belong to a simple
dead organisms). It provides Mutation Theory
species Homo sapines
most direst and reliable evi- which has evolved bipedal
This theory put forward by
dence of evolution. locomotion high cranial
Hugo de Vries says that
evolution is a discontinuous, capacity, opposable
® Connecting Back saltatory process that oc- thumbs and etc.
curs due to sudden inherit- dominates in today's life
Connecting links are living or- able variations. forms.
ganisms with characteristics
intermediate between two
groups, e.g., Euglena (link
between plants and animals)
® Modern Synthetic Theory
Molecular and phystological
According to it five factor :
® genetic variations, heredity,
various physiological pro-
cesses, cellular structure, bio- natural selection, reproductive
chemistry, genetic composi- isolation and speciation lead
tion, etc. also provide to evolution
evolutioonary evidence e.g.,
blood plasma proteins.

l

929