Evolution Exam-1

1. The force responsible for fixing in population of neutral characteristics is a) Genetic drift b) Mutation c) Reproduction d) Genetic recombination 2. Mutation is more common when it is present in a) Recessive condition b) Dominant condition c) Constant in population d) None of these 3. Choose the correct statements I. Law of embryonic development was given by Von Baer II. Recapitulation theory was proposed by Haeckel III. Haeckel theory states that ‘Ontogeny repeats phylogeny’ IV. Haeckel theory and biogenetic law were proposed by the same person The correct combination is a) I and II b) II and III c) III and I d) I, II, III and IV 4. ‘Every cell of the body contributes gemmules to the germ cells and so shares in the transmission of inherited characters’, this theory is known as a) Theory of inheritance of acquired characters b) Theory of germplasm c) Theory of pangenesis d) Theory of mutation 5. Synthetic theory of evolution was developed by a) Several biological specialities b) Darwin c) Mendel d) Wallace 6. Natural indicator of industrial pollution is a) Algae b) Fungi c) Lichen d) Bacteria 7. Lamarckism cannot explain a) Webbed toes in aquatic birds b) Weak muscles in the son of a wrestler c) Long narrow and limbless body of snakes d) Heterophylly 8. Arrange the periods of Palaeozoic era in ascending order in a geological time scale. a) Cambrian –Ordovician –Silurian –Devonian –Carboniferous -Permian b) Cambrian – Devonian – Ordovician – Silurian –Carboniferous -Permian c) Cambrian –Ordovician – Devonian – Silurian –Carboniferous -Permian d) Silurian – Devonian – Cambrian – Ordovician – Permian - Carboniferous 9. What is common to whale, seal and shark? a) Seasonal migration b) Thick subcutaneous fat c) Convergent evolution d) Homeothermy 10. Give the name of the first organism who invaded land a) Plants b) Consumers c) Animal d) Carnivores 11. Hardy-Weinberg principle can be expressed as a) + 3 + = 1 b) + 2 + ≥ 1 c) + 2 + ≤ 1 d) + 2 + = 1 12. Identify what the given diagram indicates Tasmanian wolf Koala bear Australian Marsupials Marsupial rat Kangaroo a) Convergent evolutionb) Divergent evolution c) Recapitulation 13. Speciation is the evolutionary process by which a) A new gene pool is formed b) Evolutionary paths of the species converge c) Hybrids species are formed d) Differences in physical traits appears 14. First human like hominid is known as d) Parallel evolution a) Neanderthal man b) Homo habilis c) Dryopithecus d) Homo erectus 15. ‘Darwin’s finches’ refers to a) Fossils of birds collected by Darwin at Galapagos islands b) A type of birds present on Galapagos islands c) Migratory birds collected by Darwin at Galapagos islands d) Fossils of reptiles collected by Darwin at Galapagos islands 16. Age of fossils in the past was generally determined by radio-carbon method and other methods involving radioactive elements found in the rocks. More precise methods, which were used recently and led to the revision of the evolutionary period for different groups of organisms, include a) Study of carbohydrates/ proteins in fossils b) Study of conditions of fossilization c) Electron spin resonance (ESR) and fossil DNA d) Study of carbohydrates/proteins in rocks 17. Which of the following is not vestigial in man? a) Tail vertebrae b) Nails c) Nictitating membrane d) Vermiform appendix 18. Survival of the fittest is possible due to a) Over production b) Favourable variation c) Environmental change d) Inheritance of acquired characters 19. Which of the following branch of biology helps in to know the existence of coal? a) Palaeobotany b) Bacteriol ogy c) Economic botany d) Ecology 20. Which of the following factor is most likely to decrease the genetic diversity in a population? a) Genetic recombination b) Mutation c) Genetic drift d) Stabilizing natural selection 21. The first cellular form of life could have originated a) 2000 million years back b) 11000 million years back c) 1500 million years back d) 500 million years back 22. Origin of life as a result of chemical evolution has been properly explained by or the most logical biochemical theory of origin of life has been given by a) Stanley Miller b) Darwin c) A I Oparin d) S Fox 23. The structural similarities between the flippers of whales and the arms of human are used to show that a) Human species began life in the oceans b) Human species and whales have a common ancestry c) Whales are older than the human species d) Whales evolved from the human species 24. Fossil X is older than fossil Y if a) X was found deeper in sediment than Y b) Y was found deeper in sediment than X c) Y had less vestigial organs d) Fossil Y had a homologous and analogous organs of X 25. I. Oparin’s theory of origin of life is based on …A… II. Chemical theory of origin of life was given by …B… Choose the correct option for A and B to complete the statements I and II a) A-biological evolution; B-Oparin b) A-elemental evolution; B-Haldane c) A-organic evolution; B-Oparin and Haldane d) A-chemical evolution; B-Oparin and Haldane 26. The concept of natural selection in evolution was proposed by a) Charles Robert Darwin b) August Weismann c) Hugo de Vries d) Jean Baptiste Lamarck 27. Darwin proposed that new species evolve from ancestral forms by the a) Gradual accumulation of adaptations to changing environment b) Inheritance of acquried adaptation to the environment c) Struggle for limited resources d) Accumulation of mutations 28. Which of the following is not a correct pair? a) Mesozoic era - Age of mammals b) Origin of species - Charles Darwin c) Study of fossil – Palaeontology d) Mutation theory – Hugo de Vries 29. S L Miller’s closed flask contained a) CH b) H c) NH and H O d) All of these 30. Give the name of and 31. 32. 33. 34. 35. 36. 37. 38. 39. a) B-Ramaithecus; C-Homo erectus b) B-Ramapithecus; C-Australopithecus c) B-Australopithecus; C-Ramapithecus d) B-Australopithecus; C-Homo erectus The primate, which existed 15 million years ago, among these was a) ℎ b) ℎ c) ℎ d) Which type of growth living organism undergoes? a) Reversible b) Apical c) Accretion d) Intussusception Directional selection favours a) One extreme from over the other extreme from over intermediate from of a trait b) Both extremist form of trait c) Environmental differences d) Intermediate form of a trait What was the most significant trend in the evolution of modern man ( ) from his ancestors? a) Shortening of jaws b) Binocular vision c) Increasing brain capacity d) Upright posture For a long time it was believed that life came out of decaying and rotting matter like straw mud, etc. This was the theory of a) Catastrophism b) Abiogenesis c) Panspermia d) Chemogeny In which of the following era first mammal like reptile originated? a) Permian period b) Triassic period c) Jurassic period d) Tertiary period Darwin judged the fitness of an individual by a) Ability to defend itself b) Strategy to obtain food c) Number of offsprings d) Dominance over other individuals In the theory of evolution, Lamarck explained I. internal vital force II. effect of environment on organisms III. inheritance of acquired characters IV. use and disuse of organs Choose the correct combination a) I and II b) II and III c) I, II and IV d) I, II, III and IV Evolutionary development of a species can be studied by 40. 41. 42. 43. 44. 45. 46. 47. 48. 49. 50. 51. 52. a) DNA analysis b) Finding age by carbon dating c) Studying fossils of the species d) All of the above Phenomenon of industrial melanism demonstrates a) Reproductive isolation b) Induced mutation c) Natural selection d) Geographical isolation Diversity of living organisms is due to a) Instant changes b) Polyploidy c) Long term evolutionary changes d) Short term evolutionary changes Darwin’s book ‘Origin of New Species by Natural Selection’ was published in a) 1809 b) 1859 c) 1957 d) 1869 What is the difference between genetic drift and changes drift to the natural selection? a) Genetic drift do not requires the presence of variations b) Genetic drift rarely involves competition between the members of a species c) Genetic drift is most effective in very large populations but natural selection operates in a small isolated population d) There is no difference between genetic drift and natural selection were arose during a) Ice-age between 25000-10000 years ago b) Continental drift between 75000-10000 years ago c) Continental drift between 75000-5000 years ago d) Ice-age between 50000-10000 years ago Which phenomena confined the pouched mammals of Australia survived because of lack of competition from any other mammals? a) Continental origination b) Continental shifting c) Continental drifting d) Continental evolution Which of the following animals is not only a living fossil but also considered as connecting link? a) ℎ b) c) d) Fossils of was found in a) Java in 1891 b) India in 1921 c) Africa in 1927 d) Australia in 1945 Which of the following is a unit of natural selection? a) Genus b) Species c) Individual d) Population Industrial melanism is an example of a) Protective resemblance with the surroundings b) Defensive adaptation of skin against ultraviolet radiations c) Drug resistance d) Darkening of skin due to smoke from industries Stanley Miller proposed origin of life by a) Chemical synthesis b) Abiogenesis c) Biogenesis d) None of these Anthropoids were evolved into a) Apes, Proconsul and monkeys b) Apes, cro-magnon man and old world monkeys c) Proconsul, new world monkeys and peking man d) New world monkeys, Proconsul and Homo habilis The diagram below shows an undisturbed sedimentary strata at the bottom of an ocean. The fossils found in layer resemble the fossils found in layer . This similarity suggests that 53. 54. 55. 56. 57. 58. 59. 60. 61. 62. 63. 64. 65. a) The fossils in layer B were formed before the fossils in layer A b) Modern forms of the life may have evolved from earlier forms of life c) Vertebrate fossils are only found in sediments d) The fossils in layer A must be more complex than those in layer B Hardy –Weinberg equilibrium is known to be affected by gene flow, genetic drift, mutation, genetic recombination and a) Evolution b) Limiting factors c) Saltation d) Natural selection Struggle for existence and survival of the fittest theories were given by a) Wallace b) Darwin c) Lamarck d) None of these Theory of continuity of germplasm was given by a) August Weismann b) Lamarck c) Darwin d) Wallace The process by which different type of finches were evolved in Galapagos islands is a) Adaptive radiation b) Geographic similarity c) Geographic dissimilarity d) Unadaptive radiation An evolutionary process, giving rise to new species adapting to new habitat and ways of life is called a) Adaptive radiation b) Adaptation c) Convergent evolution d) Microevolution Natural selection is a process in which …A… variations enables better survival and ability to …B… and leave …C… number of progeny Choose the correct options for A,B and C to complete the given NCERT statement a) A-heritable, B-reproduce, C-greater b) A-non-heritable, B-reproduce, C-greater c) A-non-heritable, B-reproduce, C-lesser d) A-heritable, B-reproduce, C-lesser Which of the follows have not left any evidence of organic evolution? a) ℎ b) Cow c) d) ℎ Biological concept of species was given by a) E Mayer b) Darwin c) De Vries d) Mendel Somatic cells of gorilla, chimpanzee and orangutan have a) 44 chromosomes b) 42 chromosomes c) 46 chromosomes d) 48 chromosomes Natural selection I. tends to increase its characters that enhances survival and reproduction II. causes adaptation III. acts on organism phenotype IV. mechanism of evolution explained by Darwin Which of the following statements are correct? a) I, II, III b) I and II c) II and IV d) I and III Darwinian fitness can be estimated by a) How long different individual in a population survive b) Number of offsprings produced by different individual in population c) Individual have a large size in population d) Species recover after mass extinction The first life on earth consists of a) Provirus b) Protovirus c) Virus d) Bacteria Factor affecting the process of speciation are I. Mutation II. Recombination III. Natural selection IV. Hybridisation V. Genetic drift VI. Polyploid VII. Isolation 66. 67. 68. 69. 70. 71. 72. 73. 74. 75. 76. 77. 78. 79. 80. Choose the correct combination a) I, II, V, VII and VI b) II, VI, IV, III and V c) III, IV, V, VII and II d) I, II, III, IV, V, VI and VII Jurassic period of the Mesozoic era is characterized by a) Gymnosperms are dominant plants and first birds appear b) Radiation of reptiles and origin of mammals like reptiles c) Dinosaurs become extinct and angiosperms appear d) Flowering plants and first dinosaurs appear Blood groups-A and B are found in a) Monkeys b) Apes c) Dogs d) Cats An organism which is the connecting link between the animals and plants is a) Bacteria b) Cyanobacteria c) Euglena d) Amoeba ……… organs shows adaptive radiation. Complete the given statement with an appropriate option given below a) Homologous b) Analogous c) Progressive organs d) Similar in structure Identify the phenomenon in which a new set of population is formed the set of existing population due to the excessive change in the allele frequency a) Founder effect b) Evolutionary effect c) Bottle-neck effect d) None of the above Age of gymnosperm is a) Cenozoic era b) Mesozoic era c) Palaeozoic era d) Proterozoic era Which of the following example of variation is not important from an evolutionary standpoint? a) Genetic differences between individual organisms comprising the population b) Inherited difference between individual organisms comprising the population c) Both (a) and (b) d) Difference due to diet, health, age and accident that have no affect on an individual’s ability to survive and reproduce Organs which are anatomically different, but performs similar functions are called a) Analogous organs b) Homologous organ c) Vestigial organs d) Heterologous organs Coacervates are a) Protobionts having polysaccharide, protein and H O b) Protein aggregate c) Protein and lipid aggregates d) None of the above The primates nearest to humans in the evolutionary line is a) New world monkeys b) Apes c) Lemurs d) Echidna Primitive man was originated during a) Miocene b) Holocene c) Pleistocene d) Pliocene Survival of the fittest is the basic principle of a competition. Its importance in organic evolution was explained by a) Lamarck b) de Vries c) Darwin d) Mendel Which of the following is an example of an ancestral homology? a) Almost all modern reptiles, birds and mammals have forelimbs, a trait they also share with contemporary amphibians b) The first birds and all their descendant species have feathers, a trait that is unknown in any other group c) Humans and many insect species have eyes d) All of the above Swan-necked flask experiment proved a) Biogenesis b) Abiogenesis c) Gene therapy d) Both (a) and (b) Industrial melanism was highlighted by a) b) c) d) Rock python Edubul 81. de Vries gave his mutation theory on organic evolution, while working on ℎ a) ℎ b) c) ℎ d) 82. Which of the following statement is correct regarding the evolution of humans? I. The skull of adult chimpanzee is more like adult human skull than baby chimpanzee skull II. The skull of baby chimpanzee is more like adult human than adult chimpanzee skull III. ℎ is oldest human like fossil IV. ℎ found in Miocene rock of Africa and Europe The correct option is a) I and II b) I and III c) I and IV d) All excepts I 83. Select the correct statement from the given options a) Darwinism variation are small and directionless b) Fitness is the end result of the ability to adapt and gets selected by nature c) All mammals except whales and camels have seven cervical vertebrae d) Mutations are random and directional 84. Human arm is homologous to a) Seal flipper b) Octopus tentacle c) Bird wing d) Both (a) and (c) 85. Lamarck’s theory of evolution is also known as a) Theory of acquired characters b) Theory of genetic characters c) Theory of spontaneous characters d) Theory of impose characters 86. Which fossil man has been known from Shivalik hills in India? ℎ a) ℎ b) c) ℎ ℎ d) ℎ ℎ 87. The crosspterygian fish ′ ′ is considered as the ancestor of terrestrial tetrapods. During which period these fishes evolved into Amphibians? a) Devonian b) Silurian c) Ordovian d) Cambrian 88. ℎ is also called a) Java ape man b) First ape man c) African ape man d) Both (b) and (c) 89. According to de Vries theory, evolution is a) Discontinuous b) Jerky c) Continuous and smooth d) Both (a) and (b) 90. Which is a unit of evolution? a) Cell b) Individual c) Population d) Species 91. Primates which existed about 15 million years ago were I. ℎ II. ℎ III. ℎ IV. ℎ V. VI. Neanderthal man Choose the correct option a) I and II b) III and IV c) V and VI d) Only III 92. The Coenozoic era is often designated as a) Age of fish b) Age of reptiles c) Age of mammals d) Age of amphibians ? 93. When and who wrote the book. ℎ a) Mendel in 1809 b) Wallace in 1858 c) Lamarck in 1869 d) Darwin in 1859 94. Spontaneous generation theory was given by a) F Redi b) L Spallanzani c) Louis Pasteur d) Aristotle 95. What is the relationship between the wing of a bird and the wing of a bat? a) They are homologous because they represent modified forms of a trait present in a common ancestor (forelimbs) b) They are analogous because while each carries out the same function (fight), this trait has arisen independently as a result of convergence c) There is no relation between the wings of bird and wings of bat d) They both have undergone severe mutation 96. Given diagram depicts a) Evolutionary evidences from comparative b) Evolutionary evidences from embryology anatomy and physiology c) Evolutionary evidences from biochemistry d) Evolutionary evidences from cytology and physiology 97. lived about a) 2 million years ago b) 1.5 million years ago c) 1 million years ago d) .5 million years ago 98. The concept of chemical evolution is based on a) Crystallization of chemicals b) Interaction of water, air and clay under interse heat c) Effect of solar radiation on chemicals d) Possible origin of life by combination of chemicals under suitable environment conditions 99. The stage next to ℎ was a) Homo erectus b) Homo sapiens c) Dryopithecus d) Neanderthal man 100.What was the name of the sail ship used by Charles Darwin during the sea Voyage? a) HMS Beagle b) HSM Beagle c) HMS Eagle d) HSM Eagle IMPORTANT PRACTICE QUESTION SERIES FOR EXAM – 1 (ANSWERS) 1) 5) 9) 13) 17) 21) 25) 29) 33) 37) 41) 45) 49) 53) 57) 61) 65) 69) 73) 77) 81) 85) 89) 93) a a c a b a d d a c c c a d a d d a a c c a d d 2) 6) 10) 14) 18) 22) 26) 30) 34) 38) 42) 46) 50) 54) 58) 62) 66) 70) 74) 78) 82) 86) 90) 94) b c a b b c a b c d b c a b a a a a a a d c c d 3) 7) 11) 15) 19) 23) 27) 31) 35) 39) 43) 47) 51) 55) 59) 63) 67) 71) 75) 79) 83) 87) 91) 95) d b d b a b a c b d b a a a b b b b b a b a d c 4) 8) 12) 16) 20) 24) 28) 32) 36) 40) 44) 48) 52) 56) 60) 64) 68) 72) 76) 80) 84) 88) 92) 96) b a b c d a a d a c a d b a a b c d c c d c c a 97) b 98) d 99) a 100) a Edubull 1 (a) Genetic drift is an evolutionary force operating in small populations. It is responsible for fixing in population of neutral characteristics. 2 (b) Mutation is more common when it is present in dominant condition. The reason is that the dominant mutant gene can express in both homozygous and heterozygous conditions. 3 (d) Von Bear’s law The development of an organism proceeds from the general to the special forms and the embryos belonging to various classes closely resemble one another in their earlier stages but diverge more and more as development proceeds. He formulated Baer’s laws of embryology (i) General characteristics of the group to which an embryo belongs, develops before the special characteristics (ii) General structural relations are likewise formed before the most specific relations appear (iii) The form of any given embryo does not converge upon other definite forms but, on the contrary, separates itself from them (iv) Fundamentally, the embryo of a higher animal form never resembles the adult of another animal form (b) Charles Darwin (1809-1882) tried to suggest the physical basis of heredity by pangenesis theory and suggested that every cell of the body contributes gemmules to the germ cells and so shares in the transmission of inherited characters. 4 5 6 7 8 9 (a) The synthetic theory of evolution is the result of the work of a number of scientist namely T Dobzhansky, RA Fisher, JBS Haldane, Sewall Wright, Ernst Mayer. Homology is also seen amongst the molecules. This is called molecular. For example, the proteins found in the blood of man and ape are similar. The phylogeny of an organism can be traced by using the base sequence in nucleic acids and the amino acid sequence of the proteins in related organisms (c) Lichen are very sensitive to the air pollution specially to the sulphur dioxide. Lichen are the symbiotic association of algae and fungi. Generally, lichens are not found in the industrial areas (b) Lamarckian theory is also known as theory of inheritance of acquried characters or theory of use and disuse of organs. This theory can not explain the reason of weak muscles in the son of a wrestler. (a) The correct order of the poriods of Palaeozoic era in ancending order in a geological time scale is− Cambrian –Ordovician –Silurian –Devonian –Carboniferous -Permian (c) Distantly related animals (as whale, seal and shark) inhabiting similar habitats often develop similar morphological features that make them look similar. This is termed as adaptive convergence or convergent evolution. Dogfish (pisces) and whale (mammals) have acquried aquatic character though distantly related. 10 11 12 13 (a) Plants were the first who invaded land. They prominanted modern era (d) +2 + =1 Hardy-Weinberg Principle It was proposed by GH Hardy an English mathematician and W Weinberg a German physician independently in 1908 (i) It describes a theoretical situation in which a population is undergoing no evolutionary change. This is called genetic or Hardy-Weinberg equilibrium (ii) It can be expressed as + 2 + = 1 or( + ) = 1 (iii) Evolution occurs when the genetic equilibrium is up set (evolution is a departure from Hardy-Weinberg equilibrium principle) The sum of total of Allelic frequency( + ) = 1 + 2 + or ( + ) Where, = % homozygous dominant individuals = frequency of dominant allele = % homozygous recessive individuals = frequency of recessive allele 2 = % heterozygous individuals Realize that ( + ) = 1 (three are only 2 alleles) +2 + = 1 (these are the only genotypes) Example An investigator has determined by the inspection that 16% of a human population has a recessive trait. Using this information, we can calculate all the genotypes and allele frequencies for the population, provided the conditions for Hardy-Weinberg equilibrium are met Given = 16% = 0.16 are homozygous recessive individuals Therefore, = √0.16 = 0.4 = frequency of recessive allele = 1.0 − 0.4 = 0.6 = frequency of dominant allele = 0.6 × 0.6 = 0.36 or 36% are homozygous dominant individuals 2 = 2 × 0.6 × 0.4 = 0.48 = 48% are heterozygous individuals Or = 1.00 − 0.52 = 0.48 Thus, 84% (36+48) have the dominant phenotype (b) Divergent evolution. Divergent evolution is the accumulation of differences between groups which can lead to the formation of new species. Usually, it is a result of diffusion of the same species to different and isolated environments which blocks the gene flow among the distinct populations allowing differentiated fixation of characteristics through genetic drift and natural selection Primarily diffusion is the basis of molecular division which can be seen in some higher-level characters of the structure and function that are readily observable in organisms. For example, the vertebrate limb is one example of divergent evolution. The limb in many different species has a common origin, but has diverged somewhat in overall structure and function (a) Speciation is an evolutionary process by which new biological species arises. There are five types of speciation : allopatric,peripatric, parapatric, and sympatricand artificial (i) Allopatric Speciation It occurs when a species separates into two separate groups which are isolated from one another. A physical barrier, such as a mountain range or a waterway, makes it impossible to breed with one another. Each species develops differently, based on the demands of their unique habitat or the genetic characteristics of the group that are passed on to offspring (ii) Peripatric Speciation When small groups of individuals break off from the larger groups and forms new species, this is called peripatric speciation. As in allopatric speciation, physical barriers make it impossible for numbers of groups to interbreed with one another, the main difference between allopatic speciation and peripatric speciation is that in peripatric speciation, one group is much smaller than the other (iii) Parapatric Speciation A species is spread over a large geographic area. Although it is possible for any member of the species to mate with another member, individuals only mate with those in their own geographic region (iv) Sympatric Speciation Some scientists don’t believes that this form exists. Sympatric speciation occurs when there are no physical barriers preventing any member of a species from mating with another and all members are in close proximity to one another. A new species, perhaps based on a different food source of characteristics, seems to develop. The theory is that some individuals becomes dependent on certain aspects of an environment-such as shelter or food sources, while others do not (v) Artificial Speciation Is the creation of new species by people. This is achieved through lab experiments, where scientists mostly research insects like fruit files, and in animal husbandry. Animal husbandry is the care and breeding of livestock (animals). Many agricultural products, such as dairy, meat and wool, depends on animal husbandry 14 15 (b) Homo habilis; (homo = human; habilis = able) 2-1.5 mya. Brain of Homo habilis was one half the size of a modern human. They were more sophisticated with rudimentary speech (b) Darwin’s finches refers to a type of birds present on Galapagos islands. 16 (c) Electrons Spin Resonance (ESR) measures number of charges occupying deep traps in crystal band gap. The basic principle of ESR is same as those for luminescene, i.e., electorns become trapped and stored as a result of ionising radiations, e.g., dating of tooth enamel. 17 (b) Vestigial organs are incompletely developed, i.e., rudimentary and generally non-functional organs, e.g., tail vertebrae, nictitating membrane and vermiform appendix are vestigial organs of man. Nails are not vestigial organs because these are the functional structure. 18 19 20 (b) The organisms which are provided with the favourable variations would survive because they are fittest to face their surrounding while unfit organism are destroyed (a) Palaeobotany is the branch of Palaeontolgoy in which we study the fossils of plants. Coal was formed by large pteridophyte in prehistoric time (d) 21 22 23 24 25 26 27 Stabilizing natural selection is a condition in which the conditions of natural selection become static. Due to static conditions, there is no origin of variation. That’s way, the genetic diversity decreases in the stabilizing natural selection (a) 20000 million years. Experimental Evidences of Chemical Evolution Experi ik mentally chemical theory of evolution performed by SL Miller and HC Uray in 1953. He created electric discharge in a closed flask containing CH , H , NH and water vapour at 800 C. He observed formation of amino acids. In similar experiments other the observed, formation of sugar, nitrogen bases, pigments and fats The first non-cellular forms of life could have originated-3 billion years back. The first cellular form of life did not possibly originated till about 2 billion years ago because the conditions were non-biogenic at that time. This version of biogenesis, i.e., the first form of life arose slowly through evolutionary forces from non-living molecule was accepted by majority (c) Modern theory of origin of life was proposed by A I Oparin andJ B S Haldane As per this theory origin of life is the result of long series of physico-chemical changes which brought about first by chemical evolutions and then by biological evolution. (b) Comparing structural similarities is called comparative anatomy. The more similar two different species body structures are, the closer they evolutionary linked and the more recently they shared a common ancestor (a) If the fossil is order than fossil than in the sedimentary rock or sedimentation fossil will be found deeper than the fossil . In sedimentation the layers are deposited one above the other as the time proceeds (d) A-Chemical evolution; B-Oparin and Haldane (a) As a result of struggle for existence, variability and inheritance the successive generations tend to become better adopted to their environment. These adaptations are preserved and accumulated in the individual of the species. Darwin summarised them under the heading ‘Origin of Species by Natural Selection’. (a) According to Darwin, speciation is the result of gradual accumulation of adaptations to changing environment. 28 (a) Mesozoic era is known as the age of reptiles. Coenozoic era known as age of mammals. 29 (d) The first experimentalsupport to Oparin-Haldane’s theory of origin of life came from Urey and Stanley Miller’s experiment in 1953. He built an apparatus of glass tubes and flasks in the laboratory. He created an atmosphere containing (NH ), (CH ) and (H O) in one large hydrogen (H ), flask and allowed condensed liquids to accumulate in another small flask. The ratio of methane, ammonia and hydrogen in large flask was 2 : 1 : 2. 30 (b) B-Ramapithecus; C-Australopithecus (c) ℎ survived about 14-15 million years ago during late Miocene to Pliocene. Edward Lewis (1932) obtained fossil of ℎ from Pliocene rocks of Shivalik hills of India. ℎ became extinct about 1-8 million years ago. 31 32 33 (d) In physiology, intussusception is the reception of foreign matter by living organisms and its conversion into food by ingestion, digestion and assimilation of food, including the whole process of nutrition and growth. It is the mode of interstitial growth characteristic of organic life. In botany, intussusception theory proposed by Nageli, the growth of cell walls by the intercalation of new solid particles between those already in existence. The intussusception theory is opposed to the theory of growth by apposition, which; supports that the new particles are deposited in layers on the inner side of the cell wall (a) Directional selection favours one extreme value for a particular trait in a distribution of these value. 34 (c) The first human-like being was the hominid called ℎ . The brain capacities were between 650-800cc. They probably did not eat meat. Fossils discovered in Java in 1891 revealed the next stage, i.e., . had a large brain and probably are meat ester. The Neanderthal man with a brain size of 1400 cc lived in near east and central Asia between 1,00,00-40,000 year back. They used animal skin to protect their body and burried their dead. arose in Africa and moved across continents and developed into distinct races. During ice age between 75,000-10,000 years back modern arose. 35 (b) Theory of spontaneous generation (Abiogenesis or Autogenesis). This theory states that life originated from non-living things in a spontaneous manner. This concept was held by early Greek philosophers like Thales, Anaximander, Xanophanes, Empedocles, Plato, Aristole, etc. (a) Permian period (c) Darwin realised that under the intense competition of members in a population, any 36 37 variation which favoured survival in a particular environment would increase the individual’s ability to reproduce and leave fertile offsprings. While less favourable variations decrease the chance of successful reproduction. Hence, Darwin judged the fitness of an individual by reproducing ability and the number of offsprings. 38 (d) I, II, III and IV. Lamarck’s theory (theory of acquired characters). Lakarckism includes the fourmain factors (i) Internal Vital Force All the living things and their component parts are continually increased due to the internal vital force (ii) Effect of Environment and New Needs Environment influences all the type of organisms. Any changes in environment brings about changes in organisms. It gives rise to the new needs of organisms (iii) Use and Disuse of Organs If an organ is constantly used it would be better developed whereas disuse of organ results in its degeneration (iv) Inheritance of Acquired Characters Whatever an individual acquires (to possess) characters in its life time due to internal vital forces effect of environment, new needs and use and disuse of organs, they are inherited (transmitted) to the next generations. After several generations, the variations are accumulated upto such extent that they give rise to new species Objection in Lamarck Theory (i) Boring of pinna (external ear) and nose of women is never inherited to the next generations (ii) The wrestler’s powerful muscles are not transmitted to the offspring (iii) European ladies wear tight waist garments in order to keep their waist slender but their off spring at the time of birth have normal waists (iv) Chinese women used to wear irons shoes in order to have small feet, but their children at the time of birth have always normal feet 39 (d) DNA analysis, finding age by carbon dating, studing fossils of species, these all are the methods through which evolutionary development of a species can be studied (c) Phenomenon of industrial melanism demonstrates natural selection, e.g., occurrence of dark (melanic) form of insects in regions with high industrial pollution. 40 41 42 (c) Diversity of living organism occurs due to the long term evolutionary changes which accumulated gradually in the organisms (b) Darwin’s book Origin of New Species by Natural Selection was published in 1859. 43 44 45 46 47 48 49 (b) Natural selection leads to the competition between the members of same species or different species but in genetic drift there is very little competition between the members of the same species (a) Homo sapiens sapiens (the man of today) appeared about 25000 years ago and started spreading all over the world about 10,000 years ago. Morphologically, the transition is marked merely by slight raising of skull cap, thining of skull bones and cranial capacity (1300-1600 CC) and formation of four flexor in vertebral column (c) Continental drift pouched mammals of Australian survived because of lack of competition from other mammals or animals (c) is a living fossil and also considered as connecting link between Annelida and Mollusca. (a) Fossils of Homo erectus (Java ape man) were obained from Java and the similar fossils were found in the cave near Peking China in the 1891. They were named Homo erectus pekinensis (d) Natural selection is the differential success in reproduction and it leads to the adaptation of organisms to their environment. Thus, natural selection occurs through an interaction between the environment and the population (a) Industrial melanism is an example of directional selection, changing, environment leading to change in the phenotypic/genotypic constitution of a population. 50 (a) Stanley Miller proposed that the life has originated in the sea due to reactions taken place between the organic compounds. 51 (a) Anthropoid are like a human being or an ape Examples for Anthropoid Gorillas, chimpanzees and gibbons are all anthropoid apes, having long arms, no tails and highly developed brains. Monkeys, apes and humans, proconsul, are all anthropoids (b) These fossils demonstrates gradualism,the theory on the time frame of evolution that states that the species gradually changes over time. Since, the fossils are found in the different layers of sedimentary rocks, the older layer contains species that evolved into new species with some changes into the new layer of rock (d) The Hardy –Weinberg law states that the gene and genotypic frequencies in a Mendelian population remain constant generation after generation if there is no selection, mutation, migration or random drift. 52 53 54 (b) Darwin gave both theories−struggle for existence and survival of the fittest. 55 56 57 58 59 60 (a) Theory of continuity of germplasm was give by August Weismann (1834-1914). Theory of continuity of germplasm by August Weismann (1834-1914). A German biologist, was the main opposer of the inheritance of acquired characters. He put forward the theory of continuity of germplasm. According to Weismann, the characters influencing the germ cells are only inherited. There is a continuity of germplasm (protoplasm of germ cells) but the somatoplams (protoplasm of somatic cells) is not transmitted to the next generation. Hence, it do not carry characters to the next generation. Weismann cut off the tails of rats for as many as 22 generations and allowed them to breed, but tailless rats were never born (a) Adaptive radiation. Examples of adaptive radiation are (i) Darwin’s Finches of Galapagos Island They had common ancestors but different types of modified beaks according to their food habits. Darwin differentiated thirteen species of the finches according to their food habits (ii) Australian Marsupials Darwin explained that adaption radiation gave rise to the varieties of marsupials (pouched mammals) in Australia by the same process of adaptive radiation as found in the finches of Galapagos Islands. (iii) Placental mammals in Australia exhibit adaptive radiation in evolving into varieties of placental mammals each of which appears to be similar to corresponding marsupials (a) When a group of organisms shares a homologous structure, which is specialized to perform a varity of different functions, it shows adaptive radiation, which represents evolution of new forms in several directions from the common ancestral type (divergence). (a) A-Inheritable, B-Reproduce, C-Greater (b) Among these, cow does not left any evidence of organic evolution. (a) Biological concept of species was given by Ernst Mayer. Alternative ways of defining a species Biological Definitions Aspect Breeding A group of organisms capable of interbreeding and producing fertile offspring A group of organisms Genetic showing close similarity in genetic karyotype A group of organisms Ecological sharing the same ecological niche; no two species can share the same ecological niche A group of organisms Evolutionary sharing a unique collection of structural and functional characteristics 61 62 63 64 65 66 67 (d) Somatic cell of gorilla, chimpanzee and orangutan have 48 chromosome (24 pairs) while humans have 46 chromosome (23 pairs) (a) Natural selection (i) Tend to increase the characters that enhance survival and reproduction (ii) Cause adaptation (b) Darwinian fitness can be estimated by the number of offspring produced by different individual in a population. The organisms which have favourable variation in accordance with environment have more offspring than the other which don’t variations in accordance with environment (b) Protoviruses are considered as the first life on earth. (d) All new species develop from the pre-existing species. The phenomenon of the development of a new species from the pre-existing ones is called speciation. A species is a collection of demes. The deme is a group of population with a common gene pool. Mutation, recombination, natural selection, hybridization, genetic drift polyploidy, isolation, all of these factors affects the phenomenon of speciation (a) Jurassic period is the second geological period of Mesozoic era. In this period, the gymnosperms were dominant and the plants included ferns, cycads, Ginkgo, rushes and conifers, among animals, important invertebrates included anamniotes, corals, brachiopods, bivalves and echinoids. Reptiles dominated the vertebrates and the first flying reptiles, the pterosaurs appeared. The first primitive bird, ℎ also made its appearance. (b) Evidences for common ancestory of great apes and man are as follows Evidence from Blood Protein It has been proved by the blood protein tests that man is most closely related to great apes (Chimpanzee and Gorilla) and next closest, in order are the old world monkeys the new world monkeys and tarsiers Evidence from Blood Group In humans four blood groups A, B, AB and O occurs. The blood 68 69 70 71 72 73 groups A and B are found in apes but not in monkeys. This indicates that human beings are more closely related to apes than to monkeys Evidence from Haemoglobin There is 99% homology in haemoglobin of man and gorilla. This suggests that the two are closely related (c) Euglena is a member of protist kingdom. It has both the animals and plant characteristics. That’s way, it is considered as the connecting link between animals and plants (a) Homologous organ. Concept of adaptive radiation in evolution was developed by HF Osborn in 1902. Adaptive radiation is also called divergent evolution. Homologous organ shows the adaptive radiation (a) Founder Effect Sometime the change in allele frequency is so different in the new sample of population that they become a different species. The original drifted population becomes founders and the effect is called founder effect. Generally, this effects operates when a population drifted to the new geographical area permanently (b) Mesozoic era (d) Difference in diet, health age and accident do not affect organism’s hereditary material. Therefore, it is not important in evolutionary point of view (a) Analogous Organs The organs which have similar functions but are different in their details and origin are called analogous organs. The analogous organs shows convergent evolution 74 (a) Oparin and Sydney Fox held that large organic molecules, synthesized abiotically on primitive earth, formed large colloidal aggregates due to intermolecular attraction. These colloidal particles were called coacervates, which are protobionts having polysaccharide, protein and water. 75 (b) Humans blood group are as A, AB, B, O. Blood groups A and B are also found in apes, but not in monkeys. This indicates that human beings are more closely related to apes than to monkeys (c) ℎ (first ape-man) lived from 4 to 1.5 million years ago in cave during Pleistocene period. It was erect posture, omnivorous and have cranial capacity of 500-700 cc. 76 77 (c) Darwin gave theory to explain organic evolution. The main postulates, which formed the basis of Darwin’s theory were-over production, limited resources, struggle for existence, variations, survival of the fittest (natural selection) and formation of new species. 78 79 (a) Almost all modern reptiles, birds and mammals, have forelimbs means, they all have same basic plan of the structure but they perform different functions. This phenomenon is called ancestral homology (a) Pasteur performed a swan-necked flasked experiment for proving biogenesis, according to biogenesis, all the living oranisms have originated from other living organisms. This experiment disproved the concept of spontaneous generation completely. 80 (c) Industrial melanism is a term used to describe the evolutionary process, in which darker individuals come to predominate over lighter individuals. Since, the industrial revolution as a result of natural selection. Until 1848, almost every individual of peppered moth ( ) captured in Great Britain had light-coloured wings with black specklings. In 1848, a black form of moth was recorded in Manchester and by 1895, 98 of the peppered moth population in Manchester was black. This black melanic form arose by a recurring random mutation. 81 (c) deVries gave his mutation theory on organic evolution, while working on ℎ (4’O clock plant). 82 (d) The skull of baby chimpanzee is more like adult human skull than the adult chimpanzee skull. Dryopithecus is the most oldest human like fossil. It is considered as the common ancestor of both human and ape. Dryopithecus was found in miocene rock of Africa and Europe (b) Fitness (survival of the fittest) is a result of selection and proliferation of only those organisms, which were most suitably adapted to the environment and get selected by nature. 83 84 85 (d) Both (a) and (c). Homologous Organs The organs which have the same fundamental structure but are different in functions are called homologous orangs. These organs follows the same basic plan of organization during development. But in adult condition, these organs are modified to perform different function as an adaptation to the different environment. Homologous organs are the resultant of divergent evolution Implants homologous organs may be a those of Bougainvillea or a tendril of Cucurbita, both arising in the axillary position (a) Lamarck’s theory (theory of acquired characters). Lakarckism includes the fourmain factors (i) Internal Vital Force All the living things and their component parts are continually increased due to the internal vital force (ii) Effect of Environment and New Needs Environment influences all the type of organisms. Any changes in environment brings about changes in organisms. It gives rise to the new needs of organisms (iii) Use and Disuse of Organs If an organ is constantly used it would be better developed 86 87 88 89 whereas disuse of organ results in its degeneration (iv) Inheritance of Acquired Characters Whatever an individual acquires (to possess) characters in its life time due to internal vital forces effect of environment, new needs and use and disuse of organs, they are inherited (transmitted) to the next generations. After several generations, the variations are accumulated upto such extent that they give rise to new species Objection in Lamarck Theory (i) Boring of pinna (external ear) and nose of women is never inherited to the next generations (ii) The wrestler’s powerful muscles are not transmitted to the offspring (iii) European ladies wear tight waist garments in order to keep their waist slender but their off spring at the time of birth have normal waists (iv) Chinese women used to wear irons shoes in order to have small feet, but their children at the time of birth have always normal feet (c) Fossil of ℎ ℎ reported from Shivalik hills (India) from the rocks of Miocene epoch (about 20-25 million years ago). (a) Devonian (c) Australopithecus (first ape man) Australopithecus africanus appeared about 5 million years ago and is also called African ape man. He was about 1.5 meters high and had human as well as ape characters. Australopithecus africanus had also gave rise to man like apes called Australopithecus robustus and Australopithecus boisei along a separate line end that ends blindly (d) Hugo de Vries pioneered the theory of mutation to explain the mechanism of evolution. According to him evolution is discontinuous and jerky process. Frequency of a mutated gene in population is expected to increase if that gen is selected by nature. 90 (c) Population is the unit of evolution. The individuals of a population form a unique set of genotype or gene pool and local environmental factors act as selective agents to alter the gene pool in ways that adapt the organisms to the local conditions. Thus, each population of a species follows its own course of evolution. 91 (d) The fossils Dryopithecus africanus was discovered from Miocene rock of Africa and Europe. It lived about 20-25 million years ago. Dryopithecus gave rise to the Ramapithecus which was on the direct line of human evolution. They appeared about 14-15 million years ago (c) Coenozoic is regarded as age of mammals. In this era, varity of mammals like whale, bat and man appeared for first time. 92 93 94 (d) In 1859, Darwin published his observations and conclusion under the name ‘origin of species’. Darwin’s book became very popular and it had changed people’s thinking about organic evolution (d) Spontaneous generation theory was given by Aristotle. According to this theory, life originated not only from living but also from non-living forms, spontaneously. 95 96 97 98 99 100 (c) Both (a) and (b). Divergent evolution is the accumulation of differences between groups which can lead to the formation of new species. Usually, it is a result of diffusion of the same species to different and isolated environments which blocks the gene flow among the distinct populations allowing differentiated fixation of characteristics through genetic drift and natural selection Primarily diffusion is the basis of molecular division which can be seen in some higher-level characters of the structure and function that are readily observable in organisms. For example, the vertebrate limb is one example of divergent evolution. The limb in many different species has a common origin, but has diverged somewhat in overall structure and function (a) In the given diagram, the evolution of heart is in dictated from the two chambered heart of fishes to the most evolved four-chambered heart of mammals. It is an example of evolution from comparative anatomy and morphology (b) 1.5 million years ago (d) The concept of chemical evolution is based on possible origin of life by combination of chemical under suitable environmental conditions. (a) Character of Homo erectus (1.6 million to 200 000 years ago) Upright human protruding jaw, no chin, thick brow ridges and a long skull (i) teeth smaller than in habilis (ii) much larger brain than habilis (1000 mm) (iii) may have had advanced speech controlled fire (iv) made more sophisticated tools then predecessors (v) left Africa and spread throughout Asia and Europe (a) Based on observation made during a sea voyage in a sail ship called HMS Beagle round the world. Charles Darwin conclude that the existing living forms share similarities to varying degrees not only among themselves but also with the life forms that existed millions of years ago –