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CBSE Questions for Class 12 Medical Biology Evolution Quiz 4 - MCQExams.com
CBSE
Class 12 Medical Biology
Evolution
Quiz 4
Evolutionary convergence is characterised by
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Development of dissimilar characteristics in closely related groups
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Development of a common set of characteristics in the group of different ancestry
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Development of characteristics by random mating
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Replacement of common characteristics in different groups
Explanation
Convergent evolution is the process, whereby organisms not closely related, independently evolve similar traits as a result of having to adapt to similar environments or ecological niches. Thus, option B is correct.
Evolutionary convergence does not explains development of dissimilar characteristics in closely related groups, development of characteristics by random mating and replacement of common characteristics in different groups.
Which is the latest era of geological time scale?
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Azoic
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Proterozoic
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Coenozoic
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Mesozoic
Explanation
The Azoic era is the era without life which includes the origin of the earth, its cooling down and other changes to make it suitable for life forms. The Proterozoic era (2000 million yrs ago and spanned for 1500 million years), the era of early life, is marked by a build-up of oxygenic atmosphere and appearance of the first eukaryotic cell. Mesozoic era (from 230 million years ago to 63 million yrs ago) is the era of medieval life and includes three periods namely, Cretaceous (135 million years), Jurassic (180 million years) and Triassic (225 million years). It is also known as the age of gymnosperms or age of reptiles. The Cenozoic era is the era of modern life and is also known as the age of mammals and angiosperms. It began 63 million yrs ago and is still continuing which makes it the most recent/latest. Thus the correct answer is option C.
Angiosperm arose in the ................ period.
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Carboniferous
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Cretaceous
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Triassic
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Tertiary
Explanation
Flowering plants (angiosperms) arose close to the beginning of the Cretaceous and became more abundant as the period progressed. The Late Cretaceous was a time of great productivity in the worlds oceans, as borne out by the deposition of thick beds of chalk in western Europe, eastern Russia, southern Scandinavia, the Gulf Coast of North America, and western Australia. The Cretaceous ended with one of the greatest mass extinctions in the history of Earth, exterminating the dinosaurs, marine and flying reptiles, and many marine invertebrates. Thus, option B is correct. Angiosperm were not arose in carboniferous period, triassic period and tertiary period.
Mammals arose from reptiles in
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Jurassic period of mesozoic era
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Triassic period of mesozoic era
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Cretaceous period of mesozoic era
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Carboniferous age
Explanation
Cretaceous period of the mesozoic era was the last phase. It was considered as the longest phase of the mesozoic era. It was also known as the age of reptiles. In this era, the mammals arose from the reptiles. The transition from reptile to mammal were the evolution of warm-bloodedness, of molar occlusion, of the three-ossicle middle ear, of hair, and of mammary glands.
So, the correct answer is option C.
Galapagos finches are associated with
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Linnaeus
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Darwin
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Hugo de Vries
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Muller
Explanation
Darwin's finches (also known as the Galapagos finches) are a group of about fifteen species of passerine birds. They often are classified as the subfamily Geospizinae or tribe Geospizini. It is still not clear to which bird family they belong, but they are not related to the true finches. They were first collected by Charles Darwin on the Galapagos Islands during the second voyage of the Beagle. All are found only on the Galapagos Islands, except the Cocos finch from Cocos Island. Thus, the correct answer is option B.
Convergent evolution is illustrated by
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Rat and dog
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Bacterium and protozoan
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Starfish and cuttle fish
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Dogfish and whale
Explanation
Convergent evolution is the independent evolution of similar features in species of different lineages. Convergent evolution creates analogous structures that have similar form or function, but that were not present in the last common ancestor of those groups. Dogfish is a cartilaginous fish and a whale is a mammal both have streamlined body and show vivipary but belong to totally different groups. The former is a fish and later being a tetrapod mammal. Dogfish and whale are the examples of convergent evolution in animals as both of them have more or less similar body organization.
Therefore, the correct answer is option D.
Dinosaurs dominated the earth about
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10 million years ago
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50 million years ago
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180 million years ago
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500 million years ago
Explanation
The first small dinosaurs appeared during Triassic period (225 million years ago) of Mesozoic era. This makes option D incorrect as dinosaurs did not appear 500 million years ago.
Jurassic period (180 million years ago) is marked by diversification of dinosaurs; large dinosaurs dominated the earth. This makes option C correct.
The asteroid impact at the end of Cretaceous period around 60 million years ago caused mass extinction of dinosaurs thereby eliminating them. Asteroid hit increased the metal iridium concentration on earth. This makes options A and B incorrect as dinosaurs were extinct by 50 and 10 million years ago. Therefore, the correct answer is option C.
In cambrian time, the dominant arthropods were
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Trilobites
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Cockroach
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Millipede
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Sacculina
Explanation
Trilobites were the dominant species during the Cambrian Period, 540 to 490 million years ago. They are a fossil group of extinct marine arthropods that form the class
Trilobita
. They finally disappeared in the mass extinction at the end of the Permian about 250 million years ago.
Therefore, the correct answer is option A.
Wings of mosquito, bats, birds is ..................... evolution.
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Convergent
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Divergent
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Adaption
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Parallel
Explanation
Convergent evolution is the process whereby organisms not closely related (not monophyletic), independently evolve similar traits as a result of having to adapt to similar environments or ecological niches. Wings of mosquito, bats, birds are examples of convergent evolution as these organisms not closely related (not monophyletic), independently evolve similar traits as a result of having to adapt to similar environments. Thus, option A is correct.
Divergent evolution is the accumulation of differences between groups, which can lead to the formation of new species, usually 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.
Parallel evolution is the evolution of geographically separated groups in such a way that they show morphological resemblances.
Adaptation is the evolutionary process whereby a population becomes better suited to its habitat.
Jurassic period of the mesozoic era is characterised where
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Flowering plants and first dinosaurs appear
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Gymnosperms are dominant plants and first birds appear
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Radiation of reptiles and origin of mammal like reptiles
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Dinosaurs become extinct and angiosperms appear
Explanation
The Jurassic Period was the second segment of the Mesozoic Era. It occurred from 199.6 to 145.5 million years ago, following the Triassic Period and preceding the Cretaceous Period. The most important event in this period include dominance of reptiles, gymnosperms
continue
as dominant and origin of toothed birds (first birds). Hence option B is correct.
Adaptive radiation occurs in
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Predator free area
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Small and isolated populations
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Flightless and asexually reproducing populations
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Sexually reproducing population
Explanation
In evolutionary biology, adaptive radiation is a process in which organisms diversify rapidly into a multitude of new forms, particularly when a change in the environment makes new resources available, creates new challenges and opens environmental niches. Adaptive radiation occurs in sexually reproducing population to create multitude new forms and not in predator free area, small and isolated populations and flightless and asexually reproducing populations. Thus, option D is correct and other options are wrong.
Archeopteryx
, a transitional fossil between birds and reptiles was discovered from the rocks of which period?
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Jurassic
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Archeozoic era
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Cretaceous
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Triassic
Explanation
Archaeopteryx
is considered by many to be the first bird or a connecting link between the reptiles and the birds. It is actually intermediate between the present birds and the predatory dinosaurs. This is the bird which belongs to the Jurassic period which was present about 150 million years ago.
Thus, the correct answer is option A.
The animal group which doesn't exist in Galapagos island is
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Insects
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Protozoa
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Crustacea
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Amphibian
Explanation
Amphibians are absent in Galapagos islands as they could not leave the mainland and travel to the island by crossing saline water.
Hawaiian honeycreeper (birds) are an example of
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Darwin's Finches
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Adaptive radiation
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Convergent evolution
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Both A and B
Explanation
Adaptive radiation is the relatively fast evolution of many species from a single common ancestor. It occurs when an organism enters a new area and different trait affect its survival.
An example of adaptive radiation is Hawaiian honeycreeper is small, passerine birds.
They are closely related to the rosefinches in the genus Carpodacus. Their great morphological diversity is the result of adaptive radiation in an insular environment.
Hence, Hawaiian honeycreeper (birds) are an example of Adaptive radiation.
So, the correct answer is 'Adaptive radiation '.
Darwin's finches are the good example of
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Convergent evolution
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Industrial melanism
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Connecting link
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Adaptive radiation
Explanation
Darwin's finches are known for their diverse beak shapes and structures. This arises due to different feeding habit and habitat and is an example of adaptive radiation. Adaptive radiation refers to the diversification of organisms from their ancestral species due to change in habitat, feeding habit etc.
So, option D is the right choice.
Same group of ancestors have formed the mammals adapted to running, flying and swimming. This proves
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Speciation
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Genetic drift
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Adaptive convergence
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Adaptive radiation
Explanation
In evolutionary biology, adaptive radiation is a process in which organisms diversify rapidly into a multitude of new forms, particularly when a change in the environment makes new resources available, creates new challenges and opens environmental niches. Thus, option D is correct.
Adaptive convergence is a form of evolution in which two unrelated (or distantly related) species evolve very similar forms due to similar selective pressures. Thus, option C is wrong.
Genetic drift or allelic drift is the change in the frequency of a gene variant (allele) in a population due to random sampling. Thus, option B is wrong.
Speciation is the evolutionary process by which new biological species arise. Thus, option A is wrong.
Which one of the following options gives one correct example each of convergent evolution and divergent evolution?
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Eyes of octopus and mammals - Bones of forelimbs of vertebrates
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Thorns of
Bougainvillea
and tendrils of
Cucurbita
- Wings of butterflies and birds
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Bones of forelimbs of vertebrates - Wings of butterfly and birds
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Thorns of
Bougainvillea
and tendrils of
Cucurbita
- Eyes of octopus and mammals
Explanation
Convergent evolution creates "analogous structures" that have
similar from or function but were not present in the last common
ancestor.
eg:- eye of octopus & mammals.
Divergent evolution is accumulation of differences between closely
related populations within a species, adding to specification.
It creates homologous structure that have similar structure
different function.
eg :- bones of forelimb of vertebrates.
Homologous organs like the limbs of a horse and flipper of whale indicate
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Convergent evolution
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Discontinuous evolution
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Divergent evolution
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Mutational variations
Explanation
The structures which are similar in their morphology, anatomy, genetics and embryology but dissimilar in their function are called as homologous organs. Many mammals have similar limb structures. The flipper of a whale, the wing of a bat, and the leg of a cat are all very similar to the human arm.
Divergent evolution is the accumulation of differences between groups, which can lead to the formation of new species, usually 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.
Being all mammals, whale, dolphin, bat, monkey and horse have some common trait, but they also show conspicuous differences.
This is due to the phenomenon of
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Normalisation
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Genetic drift
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Convergence
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Divergence
Explanation
Homology refers to evolution of organisms in different directions from a common ancestry i.e., divergence. It leads to development of homologous organs that are adapted to perform different functions and have different appearance but share common basic structural plan and origin.
Divergent evolution is the accumulation of differences between groups, which can lead to the formation of new species, usually a result of diffusion of the same species to different and isolated environments.
So, the correct answer is '
Divergence'
Adaptation is a type of
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Convergent evolution
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Satabilizing selection
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Adaptive radiation
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Speciation
Explanation
In evolutionary biology, adaptive radiation is a process in which organisms diversify rapidly from an ancestral species into a multitude of new forms, particularly when a change in the environment makes new resources available, creates new challenges, or opens new environmental niches.
Hence, Adaptation is a type of Adaptive radiation.
So, the correct answer is 'Adaptive radiation'.
The process by which organisms with different evolutionary history evolve similar phenotypic adaptations in response to a common environmental challenge, is called
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Convergent evolution
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Non-random evolution
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Adaptive radiation
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Natural selection
Explanation
In evolutionary biology, convergent evolution is the process, whereby, organisms not closely related, independently evolve similar traits as a result of having to adapt to similar environments or ecological niches. Thus, option A is correct. Non random evolution occurs due to mating that has not occurred due to chance, and therefore has had human interference. Thus, option B is wrong. In evolutionary biology, adaptive radiation is a process in which organisms diversify rapidly into a multitude of new forms, particularly when a change in the environment makes new resources available, creates new challenges and opens environmental niches. Thus, option C is wrong. The process in nature by which, according to Darwin's theory of evolution, organisms that are better adapted to their environment tend to survive longer and transmit more of their genetic characteristics to succeeding generations than do those that are less well adapted is called natural selection. Thus, option D is wrong.
Hardy-Weinberg equilibrium can be disturbed by
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Mutations
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Non-random mating
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Genetic drift
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All of the above
Explanation
The conditions to maintain the Hardy-Weinberg equilibrium are no mutation, no gene flow, large population size, random mating, and no natural selection.
Hardy-Weinberg equilibrium is disturbed by deviation from any of its five conditions.
Hence, Hardy-Weinberg equilibrium can be disturbed by Mutations, Non-random mating and Genetic drift.
So, the correct answer is 'All of the above'.
Hardy Weinberg law is applicable to
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Genetic equilibrium
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Small population
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Non-random mating
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None of the above
Explanation
Hardy Weinberg law is applicable to genetic equilibrium.
The Hardy-Weinberg equilibrium is a principle stating that the genetic variation in a population will remain constant from one generation to the next in the absence of disturbing factors.
When mating is random in a large population with no disruptive circumstances, the law predicts that both genotype and allele frequencies will remain constant because they are in equilibrium.
Therefore, the correct answer is option A.
Hardy and Weinberg proposed a principle for ________ population.
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Everchanging
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Unstable
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Fast changing
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Non-evolving
Explanation
The Hardy-Weinberg principle assumes that the
allele and genotype frequencies in a
large population will remain constant from generation to generation in the absence of evolutionary influences like
mate choice, mutation, selection, genetic drift, gene flow, and meiotic drive.
So, the correct answer is option D.
At a particular locus, frequency of 'A' allele is 0.6 and that of 'a' is 0.What would be the frequency of heterozygotes in a random mating population at equilibrium?
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0.16
0%
0.48
0%
0.36
0%
0.24
Explanation
The Hardy-Weinberg equation is given as-
p$$^2$$ + 2pq + q$$^2$$ = 1
where p is the frequency of the 'A' allele and q is the frequency of the 'a' allele in the given population.
p$$^2$$ represents the frequency of the homozygous genotype AA.
q$$^2$$ represents the frequency of the homozygous genotype aa.
2pq represents the frequency of the heterozygous genotype Aa.
So, (0.6)$$^2$$ + 2pq + (0.4)$$^2$$ = 1
0.36 + 2pq + 0.16 = 1
2pq= 0.48
Hence, the frequency of heterozygotes in a random mating population at equilibrium is 0.48.
So, the correct answer is '
0.48'
Under which condition, Hardy Weinberg's law is violated?
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Natural selection
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Mutation
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Immigration and genetic drift
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All of the above
Explanation
The conditions to maintain the Hardy-Weinberg equilibrium are no mutation, no gene flow, large population size, random mating, and no natural selection.
The Hardy-Weinberg equilibrium can be disrupted by deviations from any of its five main underlying conditions.
Hence, Under which condition, Hardy Weinberg's law is violated Natural selection, Mutation and Immigration and genetic drift.
So, the correct answer is 'All of the above'.
Which of the following has initiated the formation of population genetics and associated evolutionary studies?
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Mechanistic theory of Darwin
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Hardy-Weinberg law
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Neutral theory
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Lamarkism
Explanation
The Hardy-Weinberg equilibrium is a principle stating that the genetic variation in a population will remain constant from one generation to the next in the absence of disturbing factors.
Hence, Hardy-Weinberg law has initiated the formation of population genetics and associated evolutionary studies.
So, the correct answer is 'Hardy-Weinberg law'.
Hardy and Weinberg independently proposed
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Genetic drift
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Non-evolving population
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Founder effect
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Sewall Wright effect
Explanation
The genetic variation of natural populations is constantly changing from genetic drift, mutation, migration, and natural and sexual selection.
The Hardy-Weinberg principle gives scientists a mathematical baseline of a non-evolving population to which they can compare evolving populations.
Hence, Hardy and Weinberg independently proposed Non-evolving population.
So, the correct answer is 'Non-evolving population'.
Adaptive radiation is an example for
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Directional selection
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Diversifying selection
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Stabilizing selection
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Sympatric speciation
Explanation
The disruptive selection also called diversifying selection.
It describes changes in population genetics in which extreme values for a trait are favoured over intermediate values.
In this case, the variance of the trait increases and the population is divided into two distinct groups.
A key part of the ecological theory of adaptive radiation is disruptive selection during periods of sympathy.
Hence, Adaptive radiation is an example of Diversifying selection.
So, the correct answer is 'Diversifying selection'.
Hardy Weinberg equation is
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$${p}^{2} + 2 pq + {q}^{2} = 1$$
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$$p + 2 pq + q = 1$$
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$$p + q = 4$$
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$$p + {q}^{2} +2pq = 1$$
Explanation
The equation is an expression of the principle known as Hardy-Weinberg equilibrium, which states that the amount of genetic variation in a population will remain constant from one generation to the next in the absence of disturbing factors.
To explore the Hardy-Weinberg equation, we can examine a simple genetic locus at which there are two alleles, A and a.
The Hardy-Weinberg equation is expressed as:
$$p^2$$ + 2$$pq$$ + $$q^2$$ = 1
where $$p$$ is the frequency of the "A" allele and $$q$$ is the frequency of the "a" allele in the population.
In the equation, $$p^2$$ represents the frequency of the homozygous genotype AA, $$q^2$$ represents the frequency of the homozygous genotype aa, and 2$$pq$$ represents the frequency of the heterozygous genotype Aa.
Thus, option A is correct and other options are wrong.
In a random mating population, frequency of disease causing recessive allele is 80%. What would be the frequency of carrier individual in population?
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64%
0%
32%
0%
16%
0%
100%
Explanation
$$\textbf{Correct option:}$$
$$\textbf{(B)}$$
$$\textbf{Solution:}$$
$$\bullet$$
According to the Hardy Weinberg law, the allele and genotype frequencies in a population remain constant in the absence of factors responsible for evolution. It states that the sum of all genotype frequencies can be represented as the binomial expansion of the square of the sum of
$$p$$ and
$$q$$
$$\bullet$$
This sum is equal to one : $$(p + q)^2$$ = $$p^2$$ + $$2pq$$ + $$q^2$$ = $$1$$.
$$\bullet$$
"p" is the frequency of the dominant allele, and "q" is the frequency of the recessive allele. The "2pq" in the equation shows the frequency of heterozygotes in the population.
$$\bullet$$ According to question, if it is a recessive disease then "p" is the frequency of normal dominant allele, "q" will be the frequency of disesease causing recessive allele and "2pq" will be the frequency of carrier individual.
$$\bullet$$ In the question the frequency of disease causing recessive allele is given i.e q=80% or o.8
$$\bullet$$ If p+q = 1 then, p = q - 1 => 1 - 0.8 = 0.2 or 20%
$$\bullet$$ Thus, the frequency of carrier will be = 2
X p
X q => 2
X 0.8
X 0.2 = 0.32 or 32%
Darwin's finches are an example of
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Convergent evolution
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Adaptive radiation
0%
Divergent evolution
0%
Both B and C
Explanation
Darwin's finches are a group of about fifteen species of passerine birds. They often are classified as the subfamily Geospizinae. It is still not clear to which bird family they belong, but they are not related to the true finches. They were first collected by Charles Darwin on the Galapagos Islands during the second voyage of the Beagle. All are found only on the Galapagos Islands, except the Cocos finch from Cocos Island. Darwin's finches are examples of adaptive radiation and divergent evolution.
Therefore, the correct answer is option D.
In a population at Hardy Weinberg equilibrium, allele frequency of 'A' is 0.3, the expected frequency of 'Aa' individuals is
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0%
0.21
0%
0.42
0%
0.63
0%
0.18
Explanation
To estimate the frequency of alleles in a population, we can use the Hardy-Weinberg equation.
According to this equation:-
p = the frequency of the dominant allele (represented here by A)
q = the frequency of the recessive allele (represented here by a)
For a population in genetic equilibrium:
p + q = 1.0 (The sum of the frequencies of both alleles is 100%.)
(p + q)$$^{2}$$ = 1 so p
$$^{2}$$
+ 2pq + q
$$^{2}$$
= 1
The three terms of this binomial expansion indicate the frequencies of the three genotypes:
p$$^{2}$$ = frequency of AA (homozygous dominant)
2pq = frequency of Aa (heterozygous)
q$$^{2}$$ = frequency of aa (homozygous recessive).
p+q = 1
0.3 + q = 1
q = 1 - 0.3 = 0.7
Aa = 2pq = 2* 0.3 * 0.7 = 0.42.
Thus, the correct answer is option B.
Equilibrium of gene frequencies is
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p$$^2$$
×
2pq
×
q$$^2$$ = 1
0%
$$\sigma = \sqrt{\frac{Pq}{N}}$$
0%
Hardy-Weinberg law
0%
Mutation
Explanation
$$\textbf{Correct option:}$$
$$\textbf{(C)}$$
$$\textbf{Solution:}$$
$$\bullet$$ Hardy-Weinberg law represents the equilibrium of gene frequencies.
$$\bullet$$
According to the Hardy Weinberg law, the allele and genotype frequencies in a population remain constant in the absence of factors responsible for evolution. It states that the sum of all genotype frequencies can be represented as the binomial expansion of the square of the sum of
$$p$$ and
$$q$$
$$\bullet$$
This sum is equal to one : $$(p + q)^2$$ = $$p^2$$ + $$2pq$$ + $$q^2$$ = $$1$$.
$$\bullet$$
"p" is the frequency of the dominant allele, and "q" is the frequency of the recessive allele. The "2pq" in the equation shows the frequency of heterozygotes in the population.
There are two alleles A$$_1$$ and A$$_2$$, out of which, one A$$_1$$ has nil abundance in a population, then the abundance of second allele A$$_2$$ is
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0%
0.25
0%
1.00
0%
0.40
0%
0.50
Explanation
$$\textbf{Correct option:}$$
$$\textbf{(B)}$$
$$\textbf{Solution:}$$
$$\bullet$$
p2 + 2pq + q2 = 1 is the Hardy-Weinberg principle and according to this principle the
equilibrium is established between frequencies of allele in random mating population and these gene frequency
remain constant from generation to generation.
$$\bullet$$
H
ere, p represents the frequency of the "A" allele and q is the frequency of the "a" allele in the population.
$$\bullet$$
Thus, $$p^2$$ represents the frequency of the homozygous dominant AA, $$q^2$$ represents the frequency of the homozygous recessive aa, and 2pq represents the frequency of the heterozygous Aa.
$$\bullet$$
Further, it also states that the sum of the allele frequencies for all the alleles at the locus should be 1, so p + q = 1.
$$\bullet$$
According to the question, the genotype frequency of A$$_1$$ allele = q = 0. Since p + q = 1; thus the frequency of A$$_2$$ allele or p will be p = 1 - q ; p= 1 - 0 = 1.
$$\bullet$$ Thus, the abundance of
A$$_2$$ allele will be 1.
In a random mating population frequency of dominant allele is 0.What will be the frequency of recessive phenotype?
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0%
0.49
0%
0.09
0%
0.3
0%
0.21
Explanation
$$\textbf{Correct option:}$$
$$\textbf{(B)}$$
$$\textbf{Solution:}$$
$$\bullet$$
According to the Hardy Weinberg law, the allele and genotype frequencies in a population remain constant in the absence of factors responsible for evolution. It states that the sum of all genotype frequencies can be represented as the binomial expansion of the square of the sum of
$$p$$ and
$$q$$
$$\bullet$$
This sum is equal to one : $$(p + q)^2$$ = $$p^2$$ + $$2pq$$ + $$q^2$$ = $$1$$.
$$\bullet$$
"p" is the frequency of the dominant allele, and "q" is the frequency of the recessive allele. The "2pq" in the equation shows the frequency of heterozygotes in the population.
$$\bullet$$ According to question, the frequency of dominant allele (p) = 0.7
$$\bullet$$ If p+q=1, then q=1 - p => q = 1 - 0.7 =0.3
$$\bullet$$ Hence, t
he frequency of
recessive phenotype
= q$$^2$$ = (0.3
$$)^2$$ =
0.09.
Evolution of different species in a said area starting form a certain point and spreading to other geographical areas is known as
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Migration
0%
Divergent evolution
0%
Adaptive radiation
0%
Natural selection
Explanation
Adaptive radiation is a process in which organisms diversify rapidly into a multitude of new forms, particularly when a change in the environment makes new resources available, creates new challenges and opens environmental niches. Starting with a recent single ancestor, this process results in the speciation and phenotypic adaptation of an array of species exhibiting different morphological and physiological traits with which they can exploit a range of divergent environments. So, evolution of different species in a said area starting from a certain point and spreading to other geographical areas is known as adaptive radiation.
Natural selection is the gradual process by which heritable biological traits become either more or less common in a population as a function of the effect of inherited traits on the differential reproductive success of organisms interacting with their environment. It is a key mechanism of evolution.
Migration (human) is the movement of people from one place in the world to another for the purpose of taking up permanent or semipermanent residence, usually across a political boundary.
Divergent evolution is the accumulation of differences between groups which can lead to the formation of new species, usually 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.
Therefore, the correct answer is option C.
Which of the following geological ages is called as the golden age of reptiles?
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Archaeozoic
0%
Mesozoic
0%
Palaeozoic
0%
Coenozoic
Explanation
The Mesozoic Era is an interval of geological time from about 252 to 66 million years ago. The climate was warmer, the seasons were very mild, the sea level was higher, and there was no polar ice. It is known as age of reptiles
because this era becomes dominated by dinosaurs and
reptiles
.
Therefore, the correct answer is option B.
About thirteen different species of Galapagos finches were each adapted to eating different food. This is an example of ?
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Gene flow
0%
Adaptive radiation
0%
Sympatric speciation
0%
All of the above
Explanation
Darwin's finches were all evolved from a single variety of bird due to the availability of different variety of food. In order to survive themselves, the birds developed various modifications in their beaks from a single original beak type which means adaptive radiation or adaptation with response to the changing environmental conditions.
So, the correct answer is '
Adaptive radiation'
The first human fossil probably belonged to
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0%
Zinjanthropus
0%
Australopithecus
0%
Pleisanthropus
0%
Pithecanthropus
Explanation
The first human fossil probably belonged to Zinjanthropus. It is a
n extinct hominin postulated from a skull found in Olduvai Gorge, Tanzania, in 1959 and originally designated
Zinjanthropus
boisei by Louis S.B. Leakey. It was later renamed Paranthropus boisei.
It lived in Eastern Africa during the Pleistocene epoch from about 2.3 until about 1.2 million years ago. The brain had a small capacity of 500-550cc. Hence option A is correct.
Apes share .................. blood groups with man.
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0%
A, B, AB
0%
A, B, O
0%
AB, O
0%
A and B
Explanation
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. In humans four blood groups A, B, O and AB and occur. The blood groups A and are found in apes but not in monkeys. This indicates that human beings are more closely related to apes than to monkey. There is 99 per cent homology in haemoglobin of man and gorilla. This suggests that the two are closely related. Thus, option D is correct.
Dinosaurs occurred in which geological era in earth crust
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0%
Coenozoic era
0%
Palaeozoic era
0%
Mesozoic era
0%
Proterozoic era
Explanation
Dinosaurs are a diverse group of animals of the clade
Dinosauria
. They first appeared during the Triassic period in mesozoic era (it is lasted about 180 million years and is divided into three periods, the Triassic, the Jurassic and the Cretaceous.) 231.4 million years ago, and were the dominant terrestrial vertebrates for 135 million years
until the end of the cretaceous period
So, the correct answer is '
Mesozoic era'
Observe the given figure and identify the example which exhibit the given phenomena?
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0%
Hypochondriac people
0%
Northern elephant seal
0%
Cheetahs
0%
Both B and C
Explanation
A population bottleneck is a sharp reduction in the size of a population due to environmental events (such as earthquakes, floods, fires, disease, or droughts) or human activities (such as genocide). Such events can reduce the variation in the gene pool of a population. After an event, a smaller population, with a correspondingly smaller genetic diversity, remains to pass on genes to future generations of offspring. A classic example of a population bottleneck is that of the northern elephant seal, whose population fell to about 30 in the 1890s. Although it now numbers in the hundreds of thousands, the potential for bottlenecks within colonies remains. Genetic bottlenecks exist in cheetahs. Hypochodriac people are not an example of bottle neck effect. Thus, option D is correct.
Hardy-Weinberg Law of population genetics is applicable to the populations where mating is
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0%
Apomictic
0%
Panmictic
0%
Both A and B
0%
Selective
Explanation
Panmixia (or panmixis) means random mating. A panmictic population is one, where all individuals are potential partners. In genetics, random mating involves the mating of individuals regardless of any physical, genetic, or social preference. In other words, the mating between two organisms is not influenced by any environmental, hereditary, or social interaction. Hence, potential mates have an equal chance of being selected. Random mating is a factor assumed in the Hardy-Weinberg principle.
Which of the following factors is considered best in the evolution of man?
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0%
Extinction of reptiles
0%
Appearance of angiosperms
0%
Preference of cave life
0%
Pleistocene climate
The Java man is considered to have existed in
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0%
Java only
0%
China only
0%
Africa
0%
Java and China
Explanation
Java Man (
Homo erectus erectus
) is the popular name given to early human fossils discovered on the island of Java (Indonesia) in 1891 and 1892. Led by Eugene Dubois, the excavation team uncovered a tooth, a skullcap, and a thighbone at Trinil on the banks of the Solo River in East Java. Arguing that the fossils represented the "missing link" between apes and humans, Dubois gave the species the scientific name
Anthropopithecus erectus
, then later renamed it
Pithecanthropus erectus
. Some of the java man fossils have also found in China.
Therefore, the correct answer is option D.
Which one of the following ancestors of man first time showed bipedal movement?
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0%
Australopithecus
0%
Cro-Magnon
0%
Java ape man
0%
Peking man
Explanation
There are at least twelve distinct hypotheses as to how and why bipedalism evolved in humans, and also some debate as to when. Bipedalism evolved well before the large human brain or the development of stone tools. Bipedal specializations are found in
Australopithecus
fossils from 4.2-3.9 million years ago. The evolution of bipedalism was accompanied by significant evolutions in the spine including the forward movement in position of the foramen magnum, where the spinal cord leaves the cranium. Recent evidence regarding modern human sexual dimorphism (physical differences between male and female) in the lumbar spine has been seen in pre-modern primates such as
Australopithecus africanus
. This dimorphism has been seen as an evolutionary adaptation of females to bear lumbar load better during pregnancy, an adaptation that non-bipedal primates would not need to make. Adapting bipedalism would have required less shoulder stability, which allowed the shoulder and other limbs to become more independent of each other and adapt for specific suspensory behaviors. In addition to the change in shoulder stability, changing locomotion would have increased the demand for shoulder mobility, which would have propelled the evolution of bipedalism forward.
Therefore, the correct answer is option A.
First man to stand erect was
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0%
Cro-Magnon man
0%
Java man
0%
Neanderthal man
0%
Peking man
Explanation
Java man walked erect and lived in palaeolithic age -- the age of tools of stones and bones.
So, the correct answer is 'Java man'
Cro-Magnon man was
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0%
Herbivorous
0%
Frugivorous
0%
Sangivorous
0%
Carnivorous
Explanation
Cro-Magnon is a common name that has been used to describe the first early modern humans (early Homo sapiens sapiens) of the European Upper Paleolithic. Current scientific literature prefers the term European early modern humans (EEMH), to the term 'Cro-Magnon,' which has no formal taxonomic status, as it refers neither to a species or subspecies nor to an archaeological phase or culture. The earliest known remains of Cro-Magnon-like humans are radiocarbon dated to 43,000 years before present. Cro magnon were carnivorous and not herbivorous, frugivorous and sanguivorous. Like Neanderthals, the Cro-Magnons were primarily big-game hunters, killing mammoth, cave bears, horses and reindeer. They hunted with spears and with javelins and atlatl. Bow and arrow had not yet been invented. They would have been nomadic or semi-nomadic, following the annual migration of their prey but were less carnivorous than Neanderthals and also ate plant materials.
Therefore, the correct answer is option D.
The fossils of
Homo habilis
was discovered by Leaky et al. (1964) in
Report Question
0%
Germany
0%
Europe
0%
Australia
0%
Africa
Explanation
Homo habilis
is one of the earliest members of the genus
Homo
, has a slightly larger braincase and smaller face and teeth than in
Australopithecus
or older hominin species. But it still retains some ape-like features, including long arms and a moderately-prognathic face. Its name, which means handy man, was given in 1964 because this species was thought to represent the first maker of stone tools. Currently, the oldest stone tools are dated slightly older than the oldest evidence of the genus
Homo
. A team led by scientists Louis and Mary Leakey uncovered the fossilized remains of a unique early human between 1960 and 1963 at Olduvai Gorge in Tanzania (Africa).
Therefore, the correct answer is option D.
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Practice Class 12 Medical Biology Quiz Questions and Answers
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