CBSE Class 12 Biology HOTs Evolution

Question. In Australia, marsupials and placental mammals have evolved to share many similar characteristics. This type of evolution may be referred to as
(a) adaptive radiation
(b) divergent evolution
(c) cyclical evolution
(d) convergent evolution
Answer : D

Question. A population of a species invades a new area. Which of the following conditions will lead to adaptive radiation? 
(a) Area with large number of habitats having very low food supply
(b) Area with a single type of vacant habitat
(c) Area with many types of vacant habitats
(d) Area with many habitats occupied by a large number of species
Answer : C

Question. What is meant by the term ‘Darwin fitness’?
(a) Ability to survive and reproduce
(b) High aggressiveness
(c) Healthy appearance
(d) Physical strength
Answer : A

Question. Change in gene frequency of a population means
(a) evolution is in progress
(b) Hardy-Weinberg equilibrium is not achieved
(c) there may be a selection, migration or mutation
(d) All of the above
Answer : D

Question. Hardy-Weinberg principle can be expressed as
(a) p2 − 2 pq − q2 = 1
(b) p2 + 2pq + q2 ≥ 1
(c) p2 + 2pq + q2 ≤ 1
(d) p2 + 2pq + q2 = 1
Answer : D

Question. A gene locus has two alleles A, a. If the frequency of dominant allele A is 0.4, then what will be the frequency of homozygous dominant, heterozygous and homozygous recessive individuals in the population? 
(a) 0.16(AA); 0.24(Aa); 0.36(aa)
(b) 0.16(AA); 0.48(Aa); 0.36(aa)
(c) 0.16(AA); 0.36(Aa); 0.48(aa)
(d) 0.36(AA); 0.48(Aa); 0.16(aa)
Answer : B

Question. Survival of the fittest is possible due to the
(a) overproduction
(b) favourable variations
(c) environmental changes
(d) inheritance of acquired characters
Answer : B

Question. Darwinian fitness can be estimated by
(a) how long different individual in a population survive
(b) number of offspring produced by different individuals in population
(c) individual have a large size in population
(d) species recover after mass extinction
Answer : B

Question. Which of the following are the two key concepts of Darwinian theory of evolution?
(a) Genetic drift and mutation
(b) Adaptive radiation and homology
(c) Mutation and natural selection
(d) Branching descent and natural selection
Answer : D

Question. Which of the following situations would most likely result in the highest rate of natural selection?
(a) Reproduction by asexual method
(b) Low mutation is an stable environment
(c) Little competition
(d) Reproduction by sexual method
Answer : D

Question. Identify what the given diagram indicates?  (Image 57)
(a) Convergent evolution
(b) Divergent evolution
(c) Recapitulation
(d) Parallel evolution
Answer : B

Question. The classical example of adaptive radiation in development of new species is
(a) Darwin’s finches
(b) marsupials of Australia
(c) locomotion in mammals
(d) All of the above
Answer : D

Question. In the animals, the same structures developed along the different directions due to the adaptations to different needs. This is called
(a) convergent evolution
(b) divergent evolution
(c) disruptive evolution
(d) directional evolution
Answer : B

Question. Divergent evolution gives rise to
(a) homologous organs
(b) analogous organs
(c) Both (a) and (b)
(d) None of these
Answer : A

Question. Example of convergent evolution is
(a) Darwin finches and marsupial mouse
(b) Placental wolf and Tasmanian wolf
(c) Placental wolf and Darwin finches
(d) Tasmanian wolf and marsupial mole
Answer : B

Question. According toDarwin, the organic evolution is due to the
(a) intraspecific competition 
(b) interspecific competition
(c) competition within closely related species
(d) reduced feeding efficiency in one species due to the presence of interfering species
Answer : B

Question. Lamarck’s theory of evolution is also known as
(a) theory of use and disuse of organs
(b) theory of genetic characters
(c) theory of spontaneous characters
(d) theory of impose characters
Answer : A

Question. Hugo de Vries put forth his idea of mutation by his work on
(a) pea plant
(b) Drosophila
(c) evening primrose
(d) maize plant
Answer : C

Question. Australian marsupials are the example of
(a) homologous radiation
(b) analogous radiation
(c) adaptive radiation
(d) convergent radiation
Answer : C

Question. When more than one adaptive radiation appeared to have occurred in an isolated geographical area, it is
(a) convergent evolution
(b) divergent evolution
(c) natural selection
(d) genetic drift
Answer : A

Ques. Species occurring in different geographical area are called as
(a) sympatric
(b) allopatric
(c) sibling
(d) neopatric. 
Answer: B

Ques. Which of the following evidences does not favour the Lamarckian concept of inheritance of acquired characters?
(a) Lack of pigment in cave-dwelling animals
(b) Melanisation in peppered moth
(c) Absence of limbs in snakes
(d) Presence of webbed toes in aquatic birds
Answer: B

Ques. Weismann cut off tails of mice generation after generation but tails neither disappeared nor shortened showing that
(a) Darwin was correct
(b) tail is an essential organ
(c) mutation theory is wrong
(d) Lamarckism was wrong in inheritance of acquired characters. 
Answer: D

Ques. Evolution is
(a) progressive development of a race
(b) history and development of race along with variations
(c) history of race
(d) development of race. 
Answer: B

Ques. “Continuity of germplasm” theory was given by
(a) De Vries
(b) Weismann
(c) Darwin
(d) Lamarck. 
Answer: B

Ques. Theory of inheritance of acquired characters was given by
(a) Wallace
(b) Lamarck
(c) Darwin
(d) De Vries. 
Answer: B

Ques. ‘Origin of Species’ was written by
(a) Oparin
(b) Weismann
(c) Lamarck
(d) Darwin. 
Answer: D

Ques. Variations caused by mutation, as proposed by Hugo de Vries, are
(a) small and directionless
(b) random and directional
(c) random and directionless
(d) small and directional. 
Answer: C

Ques. According to Hugo de Vries, the mechanism of evolution is
(a) multiple step mutations
(b) saltation
(c) phenotypic variations
(d) minor mutations. 
Answer: B

Ques. The idea of mutations was brought forth by
(a) Hugo de Vries who worked on evening primrose
(b) Gregor Mendel who worked on Pisum sativum
(c) Hardy-Weinberg who worked on allele frequencies in a population
(d) Charles Darwin who observed a wide variety of organisms during sea voyage. 
Answer: A

Ques. De Vries gave his mutation theory on organic evolution while working on
(a) Pisum sativum
(b) Drosophila melanogaster
(c) Oenothera lamarckiana
(d) Althea rosea. 
Answer: C

Ques. A gene locus has two alleles A, a. If the frequency of dominant allele A is 0.4, then what will be the frequency of homozygous dominant, heterozygous and homozygous recessive individuals in the population?
(a) 0.16 (AA); 0.36 (Aa); 0.48 (aa)
(b) 0.36 (AA); 0.48 (Aa); 0.16 (aa)
(c) 0.16 (AA); 0.24 (Aa); 0.36 (aa)
(d) 0.16 (AA); 0.48 (Aa); 0.36 (aa) 
Answer: D

Ques. In a species, the weight of newborn ranges from 2 to 5 kg. 97% of the newborn with an average weight between 3 to 3.3 kg survive whereas 99% of the infants born with weights from 2 to 2.5 or 4.5 to 5 kg die. Which type of selection process is taking place?
(a) Cyclical selection
(b) Directional selection
(c) Stabilising selection
(d) Disruptive selection 
Answer: C

Ques. Artificial selection to obtain cows yielding higher milk output represents
(a) directional as it pushes the mean of the character in one direction
(b) disruptive as it splits the population into two, one yielding higher output and the other lower output
(c) stabilising followed by disruptive as it stabilises the population to produce higher yielding cows
(d) stabilising selection as it stabilises this character in the population.
Answer: A

Ques. Genetic drift operates in
(a) small isolated population
(b) large isolated population
(c) non-reproductive population
(d) slow reproductive population.
Answer: A

Ques. In Hardy-Weinberg equation, the frequency of heterozygous individual is represented by
(a) p2
(b) 2pq
(c) pq
(d) q2. 
Answer: B

Ques. In a population of 1000 individuals 360 belong to genotype AA, 480 to Aa and the remaining 160 to aa. Based on this data, the frequency of allele A in the population is
(a) 0.4
(b) 0.5
(c) 0.6
(d) 0.7.
Answer: C

Ques. The tendency of population to remain in genetic equilibrium may be disturbed by
(a) lack of mutations
(b) lack of random mating
(c) random mating
(d) lack of migration. 
Answer: B

Ques. Variation in gene frequencies within populations can occur by chance rather than by natural selection. This is referred to as
(a) random mating
(b) genetic load
(c) genetic flow
(d) genetic drift.
Answer: D

Ques. Random unidirectional change in allele frequencies that occurs by chance in all populations and especially in small populations is known as
(a) migration
(b) natural selection
(c) genetic drift
(d) mutation.
Answer: C

I. Assertion and Reason
In each of the following questions, a statement of
Assertion (A) is given followed by corresponding statement of
Reason(R).Of the statements, mark the correct answer as
(a) If both A and R are true and R is the correct explanation of A
(b) If both A and R are true, but R is not the correct explanation of A
(c) If A is true, but R is false
(d) If A is false, but R is true

Question. Assertion (A) Earth is about 15 billion years old.
Reason (R) Life appeared 500 million back after the formation of earth.
Answer : D

Question. Assertion (A) Ernst Haeckel supported the embryological similarities as an evidence of evolution.
Reason (R) The embryos of all vertebrates including humans develop a row of vestigial gill slits which are absent in adult vertebrates.
Answer : A

Question. Assertion (A) Natural selection is an outcome of the differences in survival and reproduction among individuals that show variations in one or more traits.
Reason (R) Adaptive forms of a given trait tend to become more common. Less adaptive ones becomes less common or disappear.
Answer : A

Question. Assertion (A) Earliest organisms that appeared on the Earth were non-green and presumably anaerobes.
Reason (R) The first autotrophic organisms were the chemoautotrophs that never released oxygen.
Answer : B

Question. Assertion (A) Sudden inheritable changes take place in genome of an organism due to certain factors called mutations.
Reason (R) Lamarck’s theory of evolution is popularly called the theory of continuity of germplasm.
Answer : C

Question. Assertion (A) Lichens are symbiotic relationships of algae and viruses.
Reason (R) These are sensitive to SO2 levels in the air.
Answer : D

Question. Assertion (A) Hugo de Vries said mutations cause speciation.
Reason (R) Mutations are slow changes.
Answer : C

Question. Assertion (A) Among the primates, chimpanzee is the closest relative of the present day humans.
Reason (R) The banding pattern in the autosome number 3 and 6 of man and chimpanzee is remarkably similar.
Answer : A

Question. Assertion (A) Microspheres were aggregates of organic biomolecules surrounded by film of water molecule.
Reason (R) Coacervates lack definite membrane, but do exhibit some life like characters.
Answer : D

Question. Assertion (A) Whales and mammals share similarities in the pattern of bones of forelimbs.
Reason (R) These organisms suggest occurrence of divergent evolution.
Answer : A

Question. Assertion (A) Analogous structures are different in appearance and have same function.
Reason (R) Divergent evolution leads to analogy.
Answer : C

Question. Assertion (A) Theory of chemical evolution proposed that life came from pre-existing non-living organic molecules.
Reason (R) Primitive earth conditions led to the production of organic molecules.
Answer : A

Question. Assertion (A) The theory of special creation states that God created life by his divine act of creation.
Reason (R) Louis Pasteur rejected the theory of spontaneous generation.
Answer : B

Question. Assertion (A) Lichens act as pollution indicators.
Reason (R) These do not grow in areas that are polluted.
Answer : A

Question. Assertion (A) The introduction of new alleles into the local gene pool by interbreeding of migrating individuals with members of local population is called gene migration.
Reason (R) If gene migration happens multiple times, it is called gene recombination.
Answer : C

II. Statement Based Questions

Question. Which of the following statements regarding the evolution of plants and animals are correct?
I. Amphibians evolved into reptiles.
II. Fish with stout and strong fins could move on land and go back to water. This was about 350 million years ago.
III. Giant ferns fell to form coal deposits slowly.
IV. About 65 million years ago dinosaurs died out.
V. Archaeopteryx is the connecting link between birds and reptiles.
The correct combination is
(a) I and II
(b) III and IV
(c) V and I
(d) I, II, III, IV and V
Answer : D

Question. Mark the correct statements.
I. Karl Ernst von Baer noted that embryo never pass through adult stages of other animals and thus
discarded Ernst Haeckel’s embryological support for evolution.
II. Homology in vertebrate brain indicates common ancestry.
III. Theory of acquired character was given by de Vries.
IV. After industrialisation, the white moth population decreased due to predators.
The correct option is
(a) I, II and III
(b) I, III and IV
(c) II, III and IV
(d) I, II and IV
Answer : D

Question. Which one of the following statements is true regarding the theory of natural selection?
(a) It was the first theory of organic evolution
(b) It does explain information derived from fossils
(c) It has failed to explain the origin of variations
(d) It has succesfully explained concept of speciation
Answer : C

Question. Which of the following statements would Darwinism most likely disagree with?
(a) Individuals within a population vary in the characteristics they possess
(b) Evolution is best viewed as a purpose less and nondirectional change over time
(c) Natural selection is the mechanism by which biological evolution takes place
(d) The fossil record supports the view that biological evolution has occurred
Answer : B

Question. Identify the incorrect statement.
(a) In natural selection, heritable variations enable better survival
(b) Variations due to gene flow changes allele frequency in future generation
(c) Gene flow occurs due to multiple gene migration
(d) None of the above
Answer : D

Question. Which one of the following statements is/are correct about Australopithecus?
(a) They essentially ate fruits
(b) They hunted with stone weapons
(c) They were transitional stage between ape and humans
(d) All of the above
Answer : D

Question. Which of the following is the correct sequence of events in the origin of life? 
I. Formation of protobionts.
II. Synthesis of organic monomers.
III. Synthesis of organic polymers.
IV. Formation of DNA-based genetic systems.
Choose the correct option.
(a) I, II, III and IV
(b) I, III, II and IV
(c) II, III, I and IV
(d) II, III, IV and I
Answer : C

Question. Which of the following statements are correct about the characteristics of protobionts, like microspheres as envisaged in the abiogenic origin of life?
I. They were able to reproduce.
II. They could separate the combinations of molecules from the surroundings.
III. They were partially isolated from the surroundings.
IV. They could maintain an internal environment absolutely.
Choose the correct option.
(a) I and II
(b) II and III
(c) III and IV
(d) I, II, III and IV
Answer : D

Question. Which of the following statements stands in favour of abiogenesis?
I. Spontaneous generation.
II. Origin of viruses and microbes.
III. Origin of life from living organisms.
IV. Origin of life from non-living matter.
The correct statement(s) is/are
(a) I and II
(b) II and III
(c) III and IV
(d) Only IV
Answer : D

Question. Which of the following statements are the correct pair of homologous organs?
I. Hands of manand wings of bat.
II. Wings of bat and wings of cockroach.
III. Wings of bird and wings of butterfly.
IV. Fins of fish and forelimbs of horse.
V. Forearm of human and forelimbs of horse. Choose the correct option
(a) I and II
(b) I and V
(c) III and IV
(d) IV and V
Answer : B

Question. Which of the following statements are correct?
I. Wings of insects and birds are homologous organ.
II. Wings of bats and birds are homologous organ.
III. Wings of insects and bats are analogous.
IV. Wings of insects and birds are analogous.
Choose the correct option.
(a) I and II
(b) I and III
(c) I and IV
(d) II, III and IV
Answer : D

Question. Which of the following statements about orgin of life is incorrect?
(a) The universe is almost 20 billion years old
(b) Big Bang theory explained that universe originated by a huge explosion
(c) Present day galaxies are formed by the condensation of hydrogen and helium under gravitational pull
(d) None of the above
Answer : D

Question. Identify the correct statement.
(a) Earth was formed about 4.5 billion years ago
(b) Early earth had no atmosphere
(c) The temperature of universe came down due to its expansion
(d) All of the above
Answer : D

Question. Select the incorrect statements.
I. Natural selection is essential for evolution.
II. Natural selection does not include variations.
III. Concept of natural selection was given by Hugo de Vries.
IV. Mutation is a sudden inheritable change.
V. Synthetic theory is also called Neo-Darwinism theory of evolution.
The correct combination is
(a) I, II and III
(b) II, III and IV
(c) III, IV and V
(d) II and III
Answer : D

Question. Which of the following statements are correct?
I. Survival of the fittest is based upon the characteristics that are inherited.
II. Darwin’s variations are small and directional.
III. The fitness is the end result of the ability to adapt.
IV. Genetic drift is operate in small populations.
V. Genetic drift operates in large populations.
VI. Presence of genetic drift upsets the Hardy-Weinberg equilibrium.
Choose the correct option.
(a) I, II, III and IV
(b) IV, V, VI and II
(c) I, II, III, V and VI
(d) I, II, III, IV and VI
Answer : D

Question. True statements regarding the genetic drift is/are I. It mostly occurs in smaller populations.
II. Certain alleles can be lost forever because of genetic drift.
III. Founder effects and bottle neck effects are caused by genetic drift.
IV. Mutations are primarily responsible for genetic drift.
The correct combination showing true statements is
(a) Only I
(b) III and IV
(c) II and IV
(d) All except IV
Answer : D

Question. Choose the incorrect statements.
I. The essence of Darwinian theory about evolution can be seen in the phenomenon of natural selection.
II. The rate of appearance of new forms is not linked to the evolution.
III. Adaptive ability is a complete evolution.
IV. Mutations are random and directionless.
Choose the correct option.
(a) I and II
(b) II and III
(c) I and III
(d) I and IV
Answer : B

Question. When a species gets separated geographically, it evolves separately? Which of the following conditions would determine whether they are now different species?
I. They fail to interbreed.
II. They failed to give fertile offspring.
III. They have different coloured body.
IV. They appear morphologically slightly different.
Choose the correct combination from given options.
(a) I and II
(b) II and III
(c) III and IV
(d) I and IV
Answer : A

Question. Choose the correct statements with reference to organic evolution. 
I. Flippers of whale and wings of bat exhibit analogy.
II. Wings of butterfly and wings of bird exhibit homology.
III. Organs with dissimilar structure are called analogous organs.
IV. Organs with similar structure and origin are called homologous organs.
(a) I and IV
(b) I and III
(c) III and IV
(d) II and IV
Answer : C

Important Questions for NCERT Class 12 Biology Evolution

Question. Which of the following structures is homologous to the wing of a bird? 
(a) Wing of a moth
(b) Hindlimb of rabbit
(c) Flipper of whale
(d) Dorsal fin of a shark
Answer : C

Question. Identify what is indicated in the given diagram? (Image 56)
I. Recombination
II. Adaptive radiation
III. Ecological succession
IV. Different species of penguins by mutation
Choose the correct option.
(a) Only I
(b) Only III
(c) Only IV
(d) Only II
Answer : D

Question. Which of the following is not an examples of adaptive radiation?
(a) Wombat, numbat, flying phalanger
(b) Darwin’s finches
(c) Different mammals in other parts of world
(d) Lemur and spotted cuscus
Answer : D

Question. Who proposed that long neck of giraffes evolved due to foraging of leaves on tall trees?
(a) Lamarck
(b) Darwin
(c) Malthus
(d) Aristotle
Answer : A

Question. What was the Lamarck’s explanation for long necked giraffes?
(a) Stretching of necks over many generations
(b) Short neck suddenly changed into long one
(c) Natural selection
(d) Mutation
Answer : A

Question. Which of the following differences between Lamarckism and Darwinism is incorrect? (Image 76)
Answer : B

Question. Who proposed the concept of saltation?
(a) Darwin
(b) Mendel
(c) de Vries
(d) Thomas Malthus
Answer : C

Question. What does the term ‘Saltation’ imply?
(a) Excess of species at a given area
(b) Reduced number of species due to saline environment
(c) Occurrence of variations gradually, step by step
(d) Single step large mutations
Answer : D

Question. Variations caused by mutation, as proposed by Hugo de Vries are 
(a) random and directionless
(b) small and directional
(c) small and directionless
(d) random and directional
Answer : A

Question. Hardy-Weinberg principle is the
(a) stable allele frequency in a population
(b) genetic structure of an evolving population
(c) varying allele frequency in a population
(d) phenotypic structure of a non-evolving population
Answer : A

Question. Genetic equilibrium refers to the phenomenon in which
(a) the trait remains constant in a population
(b) the total genes remain constant in a population
(c) the total genes keeps on varying in a population
(d) traits keeps on varying in a population
Answer : B 

Question. A gene locus has two alleles A, a. If the frequency of dominant allele A is 0.4, then what will be the frequency of homozygous dominant, heterozygous and homozygous recessive individuals in the population? 
(a) 0.16(AA); 0.24(Aa); 0.36(aa)
(b) 0.16(AA); 0.48(Aa); 0.36(aa)
(c) 0.16(AA); 0.36(Aa); 0.48(aa)
(d) 0.36(AA); 0.48(Aa); 0.16(aa)
Answer : B

Question. The chronological order of human evolution from early to the recent stages is
(a) Ramapithecus → Australopithecus → Homo habilis → Homo erectus
(b) Australopithecus → Ramapithecus → Homo habilis → Homo erectus
(c) Pithecanthropus pekinensis → Homo habilis → Homo erectus
(d) Australopithecus → Ramapithecus → Pithecanthropus pekinensis → Homo erectus
Answer : A

Question. The diagram given here shows the skull of two different mammals. Choose the most appropriate difference between A and B. (Image 128)
(a) Skull A has more teeth than skull B
(b) Skull A has more brain capacity than skull B
(c) Skull A is of a human and skull B is of an ape
(d) Skull A is of an ape and skull B is of human
Answer : D

Question. Which of the following conditions represents the extent of evolutionary change in Hardy-Weinberg principle?
(a) Value of ( p + q )2
(b) Difference between measured value and expected value
(c) Sum of measured value and expected value
(d) This principle cannot predict the extent of evolutionary change
Answer : B

Question. Genetic drift operates in 
(a) small isolated population
(b) large isolated population
(c) non-reproductive population
(d) slow reproductive population
Answer : A

Question. ‘XX’ is a type of selection process in evolution that promotes population changes in one particular direction. ‘XX’ favours small or large sized individuals mean size of population changes. Identify ‘XX’.
(a) Stabilising selection
(b) Directional selection
(c) Disruptive selection
(d) None of the above
Answer : B

Question. ‘PP’ is a type of selection that favours both small sized and large-sized individuals. ‘PP’ eliminates most of the members with mean expression, so as to produce two peaks in the distribution of the tract that many leads to the development of two different populations. Identify ‘PP’.
(a) Disruptive selection
(b) Stabilising selection
(c) Directional selection
(d) None of these
Answer : A

Question. Name the type of natural selection depicted in the given diagram (type I, type II and type III). (Image 93)
Answer : C

Question. Artificial selection to obtain cows yielding high milk output represents 
(a) stabilising selection as it stabilises this character in the population
(b) directional as it pushes the mean of the character in one direction
(c) disruptive as it splits the population into two, one yielding higher output and the other lower output
(d) stabilising followed by disruptive as stabilises the population of produce higher yielding cows
Answer : B

Question. In a large randomly mating population, only one person in 10,000 is an albino. What will be the frequency of carrier person of albinism?
(a) 1 in 100
(b) 99 in 10,000
(c) 2 in 10,000
(d) 1 in 50
Answer : C

Question. Allopatric speciation occurs when
(a) genetically related populations inhabit widely separated geographical area
(b) genetically unrelated populations inhabit widely separated geographical area
(c) genetically related populations inhabit the same geographical area
(d) genetically unrelated populations inhabit the same geographical area
Answer : A

Question. Choose the incorrect pair.
(a) Invertebrates were formed and active – By 500 mya
(b) Seaweeds existed – Around 320 mya
(c) First organisms that invaded land – Single-celled animals
(d) Fish with stout and strong fins – Around 350 mya
Answer : C

Question. Name the animal that evolved into the first probable amphibians and lived on both land and water.
(a) Whale
(b) Coelacanth (lobefins)
(c) Amphioxus
(d) Balanoglossus
Answer : B

Question. There was no life in
(a) Cenozoic era
(b) Mesozoic era
(c) Palaeozoic era
(d) Azoic era
Answer : D

Question. Which period in geological time scale is considered the golden era of fish?
(a) Mississippian
(b) Silurian
(c) Devonian
(d) Jurassic
Answer : C

Question. Giant dinosaurs and reptiles predominated during the Jurassic period. This period was also marked for the evolution of higher insects and angiosperms, conifers, cycads, etc. Jurassic period belongs to which era?
(a) Cenozoic
(b) Palaeozoic
(c) Mesozoic
(d) Proterozoic
Answer : C

Question. In Hardy-Weinberg equation, the frequency of heterozygous individual is represented by
(a) p2
(b) 2 pq
(c) pq
(d) q2
Answer : B

Question. The tendency of population to remain in genetic equilibrium may be disturbed by 
(a) random mating
(b) lack of migration
(c) lack of mutations
(d) lack of random mating
Answer : D

Question.  Identify the phenomenon in which a new set of population is formed from the set of existing population due to the random excessive change in the allele frequency.
(a) Founder effect
(b) Genetic drift
(c) Bottle-neck effect
(d) All of these
Answer : A

Ques. Genetic variation in a population arises due to
(a) recombination only
(b) mutation as well as recombination
(c) reproductive isolation and selection
(d) mutations only. 
Answer: B

Ques. At a particular locus, frequency of A allele is 0.6 and that of a is 0.4. What would be the frequency of heterozygotes in a random mating population at equilibrium?
(a) 0.36
(b) 0.16
(c) 0.24
(d) 0.48
Answer: D

Ques. Which of the following is not true for a species?
(a) Members of a species can interbreed.
(b) Gene flow does not occur between the populations of a species.
(c) Each species is reproductively isolated from every other species.
(d) Variations occur among members of a species.
Answer: B

Ques. Random genetic drift in a population probably results from
(a) highly genetically variable individuals
(b) interbreeding within this population
(c) constant low mutation rate
(d) large population size. 
Answer: B

Ques. In which condition, the gene ratio remains constant for any species population ?
(a) Sexual selection
(b) Random mating
(c) Mutation
(d) Gene flow 
Answer: B

Ques. Forthcoming generation are less adaptive than the parental generation due to
(a) natural selection
(b) mutation
(c) genetic drift
(d) adaptation.
Answer: B

Ques. In the developmental history of mammalian heart, it is observed that it passes through a two chambered fish like heart, three chambered frog like heart and finally four chambered stage. To which hypothesis can this above cited statement be approximated?
(a) Lamarck’s principle
(b) Mendelian principles
(c) Biogenetic law
(d) Hardy-Weinberg law 
Answer: C

Ques. Genetic drift operates only in
(a) larger populations
(b) Mendelian populations
(c) island populations
(d) smaller populations. 
Answer: D

Ques. Genetic drift is change of
(a) gene frequency in same generation
(b) appearance of recessive genes
(c) gene frequency from one generation to next
(d) none of these. 
Answer: D

Ques. Dinosaurs dominated the world in which of the following geological eras?
(a) Cenozoic
(b) Jurassic
(c) Mesozoic
(d) Devonian
Answer: B

Ques. Jurassic period of the Mesozoic era is characterised by
(a) flowering plants and first dinosaurs appear
(b) gymnosperms are dominant plants and first birds appear
(c) radiation of reptiles and origin of mammal like reptiles
(d) dinosaurs become extinct and angiosperms appear.
Answer: B

Ques. Diversification in plant life appeared
(a) due to long periods of evolutionary changes
(b) due to abrupt mutations
(c) suddenly on earth
(d) by seed dispersal. 
Answer: A

Ques. In which era reptiles were dominant ?
(a) Coenozoic era
(b) Mesozoic era
(c) Palaeozoic era
(d) Archaeozoic era
Answer: B

Ques. Which statement is correct about centre of origin of plants?
(a) More diversity in improved variety
(b) Frequency of dominant gene is more
(c) Climatic condition more favourable
(d) None of these 
Answer: A

Ques. Which period is dubbed as the age of prokaryotic microbes?
(a) Precambrian
(b) Phanerozoic
(c) Archean
(d) Proterozoic 
Answer: A

Ques. Correct order is
(a) Palaeozoic → Archaeozoic → Coenozoic
(b) Archaeozoic → Palaeozoic → Proterozoic
(c) Palaeozoic → Mesozoic → Coenozoic
(d) Mesozoic → Archaeozoic → Proterozoic.
Answer: C

Ques. Match the hominids with their correct brain size.
(A) Homo habilis (i) 900cc
(B) Homo (ii) 1350 cc neanderthalensis
(C) Homo erectus (iii) 650-800cc
(D) Homo sapiens (iv) 1400cc
Select the correct option.
(A) (B) (C) (D)
(a) (iv) (iii) (i) (ii)
(b) (iii) (i) (iv) (ii)
(c) (iii) (ii) (i) (iv)
(d) (iii) (iv) (i) (ii) 
Answer: D

Ques. Which of the following statements is correct about the origin and evolution of men ?
(a) Agriculture came around 50,000 years back.
(b) The Dryopithecus and Ramapithecus primates existing 15 million years ago, walked like men.
(c) Homo habilis probably ate meat.
(d) Neanderthal men lived in Asia between 1,00,000 and 40,000 years back.
Answer: D

Ques. The chronological order of human evolution from early to the recent is
(a) Australopithecus → Ramapithecus → Homo habilis → Homo erectus
(b) Ramapithecus → Australopithecus → Homo habilis → Homo erectus
(c) Ramapithecus → Homo habilis →Australopithecus → Homo erectus 
(d) Australopithecus → Homo habilis → Ramapithecus → Homo erectus 
Answer: B

Ques. Which of the following had the smallest brain capacity?
(a) Homo neanderthalensis
(b) Homo habilis
(c) Homo erectus
(d) Homo sapiens 
Answer: B