12th Grade > Biology
EVOLUTION MCQs
Total Questions : 49
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Answer: Option A. -> Archaeozoic
:
A
The total span of Earth’s evolution or geological time is basically divided into six eras viz., Azoic, Archaeozoic, Proterozoic, Palaeozoic, Mesozoic and Cenozoic. The second era is called the Archaeozoic era, which is also called the ‘age of early unicellular life’. In this eon, life originated in the sea from organic molecules. Prokaryotes, i.e., Monerans, evolved and diversified. Among plants, bluegreen algae originated from prokaryotes.
:
A
The total span of Earth’s evolution or geological time is basically divided into six eras viz., Azoic, Archaeozoic, Proterozoic, Palaeozoic, Mesozoic and Cenozoic. The second era is called the Archaeozoic era, which is also called the ‘age of early unicellular life’. In this eon, life originated in the sea from organic molecules. Prokaryotes, i.e., Monerans, evolved and diversified. Among plants, bluegreen algae originated from prokaryotes.
Answer: Option B. -> Assertion is correct but reason is wrong
:
B
Evolution is a slow and continuous process that takes a very long time to form a new species. Variations in species are caused not only by mutations but could also be due to other processes like genetic drift, gene flow and natural selection. Mutation isthe random change in an organism’s genetic makeup which influences the population’s gene pool. In population genetics, gene flow (also known as gene migration) is the transfer of alleles or genes from one population to another. Migration into or out of a population may be responsible for a marked change in allele frequencies in a gene pool. These variations in the relative frequency of different genotypes in a small population, owing to the chance disappearance of particular genes, lead to the phenomenon called genetic drift. 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, and this process is called natural selection.
:
B
Evolution is a slow and continuous process that takes a very long time to form a new species. Variations in species are caused not only by mutations but could also be due to other processes like genetic drift, gene flow and natural selection. Mutation isthe random change in an organism’s genetic makeup which influences the population’s gene pool. In population genetics, gene flow (also known as gene migration) is the transfer of alleles or genes from one population to another. Migration into or out of a population may be responsible for a marked change in allele frequencies in a gene pool. These variations in the relative frequency of different genotypes in a small population, owing to the chance disappearance of particular genes, lead to the phenomenon called genetic drift. 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, and this process is called natural selection.
Answer: Option D. -> 0.48
:
D
Hardy-Weinberg equation is used calculate the frequency of occurrence of alleles in a population.
It has been given that the frequency of dominent allele 'p' = 0.6 and recessive allele 'q' = 0.4.
Applying the Hardy-Weinberg Equation, p2+2pq+q2=1
The frequency of the heterozygous genotype (Aa) = 2pq
Substituting for p and q, we get
2pq = 2 x 0.4 x 0.6 = 0.48
:
D
Hardy-Weinberg equation is used calculate the frequency of occurrence of alleles in a population.
It has been given that the frequency of dominent allele 'p' = 0.6 and recessive allele 'q' = 0.4.
Applying the Hardy-Weinberg Equation, p2+2pq+q2=1
The frequency of the heterozygous genotype (Aa) = 2pq
Substituting for p and q, we get
2pq = 2 x 0.4 x 0.6 = 0.48
Answer: Option C. -> Statements I and III is correct
:
C
The process of convergent evolution starts off with two or more unrelated groups getting adapted to a similar environment. By this, they develop more or less similar features, which include analogous organs,i.e., unrelated ancestors “converge” towards the same function while adapting to a similar environment. The wings of insects and birds are examples of this. Although they belong to unrelated taxonomic groups, they have both developed wings for flight. The marsupials in Australia and South America are a good example of parallel evolution.When the ancient landmasses of Laurasia and Gondwana broke apart to form separate continents, the marsupials were also divided into two groups. While one group of marsupials was isolated on the Australian island, the other group remained in South America. Thereafter, the marsupials on both these continents evolved in a parallel manner.
:
C
The process of convergent evolution starts off with two or more unrelated groups getting adapted to a similar environment. By this, they develop more or less similar features, which include analogous organs,i.e., unrelated ancestors “converge” towards the same function while adapting to a similar environment. The wings of insects and birds are examples of this. Although they belong to unrelated taxonomic groups, they have both developed wings for flight. The marsupials in Australia and South America are a good example of parallel evolution.When the ancient landmasses of Laurasia and Gondwana broke apart to form separate continents, the marsupials were also divided into two groups. While one group of marsupials was isolated on the Australian island, the other group remained in South America. Thereafter, the marsupials on both these continents evolved in a parallel manner.
Answer: Option C. -> A slow and continuous process
:
C
Darwin's theory of evolution describes evolution as a slow and continuous process that eventually leads to evolution of new species with some different traits.
:
C
Darwin's theory of evolution describes evolution as a slow and continuous process that eventually leads to evolution of new species with some different traits.
Answer: Option B. -> Louis Pasteur
:
B
Scientist′sNameYearExperimentObservationFrancescoRedi1668HeplacedmeatintwojarsObsevedthatmaggotsandleftoneopenandtheothercovered.developedintheuncoveredjar.Lazzaro1764BoiledanimalandvegetableBrothsFoundnosignsoflivingSpallanzani1764andsealedthemimmediately.thingsinthebroth.LouisPasteur1864Boiledanimalandvegetablebroths,Observedmicroorganismsinstraightneckedflaskinastraightflaskandaswanneckedflask(tobutnotintheotherone.Thisfirmlyestablishedrestrictairmovement)andkeptbothopen.thatairisthesourceoftheseorganisms.
The given table summarises the experiments conducted by renowned scientists who disproved the theory of spontaneous generation. Conceptually, the experiments conducted by these three scientists came to lay the foundations for the theory of biogenesis (life from life) wherein they explain that life originates from pre-existing life, which completely disproves the theory of spontaneous generation (life from inanimate objects).
:
B
Scientist′sNameYearExperimentObservationFrancescoRedi1668HeplacedmeatintwojarsObsevedthatmaggotsandleftoneopenandtheothercovered.developedintheuncoveredjar.Lazzaro1764BoiledanimalandvegetableBrothsFoundnosignsoflivingSpallanzani1764andsealedthemimmediately.thingsinthebroth.LouisPasteur1864Boiledanimalandvegetablebroths,Observedmicroorganismsinstraightneckedflaskinastraightflaskandaswanneckedflask(tobutnotintheotherone.Thisfirmlyestablishedrestrictairmovement)andkeptbothopen.thatairisthesourceoftheseorganisms.
The given table summarises the experiments conducted by renowned scientists who disproved the theory of spontaneous generation. Conceptually, the experiments conducted by these three scientists came to lay the foundations for the theory of biogenesis (life from life) wherein they explain that life originates from pre-existing life, which completely disproves the theory of spontaneous generation (life from inanimate objects).
Answer: Option B. -> Australopithecus
:
B
Australopithecus was the first human ancestor to exhibit bipedalism. This revolutionary change freed the forelimbs i.e., arms and hands for grasping objects such as food and perhaps young ones. They could also look around for food and predators more easily, and were also able to run away from huge carnivores lurking around them.
:
B
Australopithecus was the first human ancestor to exhibit bipedalism. This revolutionary change freed the forelimbs i.e., arms and hands for grasping objects such as food and perhaps young ones. They could also look around for food and predators more easily, and were also able to run away from huge carnivores lurking around them.
Answer: Option D. -> All of these
:
D
The frequency of occurrence of a specific allele or gene in a population usually remains fixed until the population is exposed to certain changes like natural disasters, migration of individuals to a different population or random mating with individuals from another population. Gene frequencies could also get altered as a result of mutations, which are sudden heritable changes in genomes that can lead to variations.
:
D
The frequency of occurrence of a specific allele or gene in a population usually remains fixed until the population is exposed to certain changes like natural disasters, migration of individuals to a different population or random mating with individuals from another population. Gene frequencies could also get altered as a result of mutations, which are sudden heritable changes in genomes that can lead to variations.
Question 49. Match the events leading to the origin of life listed under column I with the time frame given under column II; choose the right answer which gives the correct combination of the alphabets of the two columns:
Column I Column II Events Time FrameAOrigin of universep3 billion years agoBOrigin of earthq4.6 billion years agoCOrigin of starsr10 billion years agoDOrigin of lifes14 billion years ago t5 billion years ago
Column I Column II Events Time FrameAOrigin of universep3 billion years agoBOrigin of earthq4.6 billion years agoCOrigin of starsr10 billion years agoDOrigin of lifes14 billion years ago t5 billion years ago
Answer: Option C. -> A = s, B = q, C = r, D = p
:
C
Studies have revealed that the universe really did have a beginning. According to the Big Bang theory, it is believed that the universe is approximately 14 billion years old. The planet earth (supposed to be unimaginably huge for us) is only a minute speck in the universe. In comparison, the earth is to the universe, what an atom is to the earth itself. This planet, we are told, originated around 4.6 billion years ago, and stars, about 10 billion years ago. On the earth, life is belived to have originated about 3 billion years ago.
:
C
Studies have revealed that the universe really did have a beginning. According to the Big Bang theory, it is believed that the universe is approximately 14 billion years old. The planet earth (supposed to be unimaginably huge for us) is only a minute speck in the universe. In comparison, the earth is to the universe, what an atom is to the earth itself. This planet, we are told, originated around 4.6 billion years ago, and stars, about 10 billion years ago. On the earth, life is belived to have originated about 3 billion years ago.
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