Evolution (last 10 years) Flashcards
- From his experiments, S.L. Miller produced amino acids by mixing the following in a closed flask: (2020)
a. CH3, H2, NH4 and water vapor at 800°C
b. CH4, H2, NH3 and water vapor at 600°C
c. CH3, H2, NH3 and water vapor at 600°C
d. CH4, H2, NH3 and water vapor at 800°C
Chapter 6 / Grade 12 evolution / page 111
d. CH4, H2, NH3 and water vapor at 800°C
NCERT
In 1953, S.L. Miller, an American scientist created similar conditions in a laboratory scale (Figure 6.1).
Add the image
He created electric discharge in a closed flask containing
CH4, H2, NH3 and water vapour at 800C.
- After about how many years of formation of earth, life appeared on this planet? (2020-Covid)
a. 50 million years
b. 500 million years
c. 50 billion years
d. 500 billion years
Chapter 6 / Grade 12 evolution / page 111
b. 500 million years
NCERT
Life appeared 500 million years after the formation of earth, i.e., almost four billion years back.
- Which of the following is the correct sequence of events in the origin of life? (2016 - II)
I. Formation of protobionts
II. Synthesis of organic monomers
III. Synthesis of organic polymers
IV. Formation of DNA-based genetic systems
a. II, III, I, IV
b. II, III, IV, I
c. I, II, III, IV
d. I, III, II, IV
a. II, III, I, IV
II. Synthesis of organic monomers
III. Synthesis of organic polymers
I. Formation of protobionts
IV. Formation of DNA-based genetic systems
CHECK THIS IN NCERT - COULDN’T FIND THIS
- Following are the two statements regarding the origin of life:
(2016 - I)
A. The earliest organisms that appeared on the earth were non-green and presumably anaerobes.
B. The first autotrophic organisms were the chemoautotroph’s that never released oxygen.
Of the above statements which one of the following options is correct?
a. (A) is correct but (B) is false
b. (B) is correct but (A) is false
c. Both (A) and (B) are correct
d. Both (A) and (B) are false
c. Both (A) and (B) are correct
CHECK THIS IN NCERT - COULDN’T FIND THIS
- Which of the following statements is not true? (2022)
a. Flippers of penguins and dolphins are a pair of homologous
organs
b. Analogous structures are a result of convergent evolution
c. Sweet potato and potato is an example of analogy
d. Homology indicates common ancestry
Chapter 6 / Grade 12 evolution / page 115
a. Flippers of penguins and dolphins are a pair of homologous organs
NCERT
Other examples of analogy are the eye of the octopus and of mammals or the flippers of Penguins and Dolphins.
- Flippers of Penguins and Dolphins are examples of: (2020)
a. Convergent evolution
b. Industrial melanism
c. Natural selection
d. Adaptive radiation
Chapter 6 / Grade 12 evolution / page 115
a. Convergent evolution
NCERT
Hence, analogous structures are a result of convergent
evolution - different structures evolving for the same function and hence having similarity.
Other examples of analogy are the eye of the octopus and of mammals or the flippers of Penguins and Dolphins.
- Which of the following refer to correct example(s) of organisms which have evolved due to changes in environment brought about by anthropogenic action? (2020)
- Darwin’s Finches of Galapagos islands.
- Herbicide resistant weeds.
- Drug resistant eukaryotes.
- Man-created breeds of domesticated animals like dogs.
a. (1) and (3)
b. (2), (3) and (4)
c. Only (4)
d. Only (2)
Chapter 6 / Grade 12 evolution / page 116
b. (2), (3) and (4)
- Herbicide resistant weeds.
- Drug resistant eukaryotes.
- Man-created breeds of domesticated animals like dogs.
NCERT
Similarly, excess use of herbicides, pesticides, etc., has only resulted in selection of resistant varieties in a much lesser time scale.
This is also true for microbes against which we employ antibiotics or drugs against eukaryotic organisms/cell.
Hence, resistant organisms/cells are appearing in a time scale of months or years and not centuries.
These are examples of evolution by anthropogenic action. This also tells us that evolution is not a directed process in the sense of determinism.
It is a stochastic process based on chance events in nature and chance mutation in the organisms
- Embryological support for evolution was disapproved by: (2020)
a. Alfred Wallance
b. Charles Darwin
c. Oparin
d. Karl Ernst von Baer
Chapter 6 / Grade 12 evolution / page 113
d. Karl Ernst von Baer
NCERT
Embryological support for evolution was also proposed by Ernst
Heckel based upon the observation of certain features during embryonic stage common to all vertebrates that are absent in adult.
For example, the embryos of all vertebrates including human develop a row of vestigial gill slit just behind the head but it is a functional organ only in fish and not found in any other adult vertebrates.
However, this proposal was disapproved on careful study performed by Karl Ernst von Baer.
He noted that embryos never pass through the adult stages of other animals.
- Embryological support for evolution was proposed by:
(2020-Covid)
a. Karl Ernst von Baer
b. Charles Darwin
c. Alfred Wallace
d. Ernst Heckel
Chapter 6 / Grade 12 evolution / page 113
d. Ernst Heckel
Embryological support for evolution was also proposed by Ernst
Heckel based upon the observation of certain features during embryonic stage common to all vertebrates that are absent in adult.
For example, the embryos of all vertebrates including human develop a row of vestigial gill slit just behind the head but it is a functional organ only in fish and not found in any other adult vertebrates.
However, this proposal was disapproved on careful study performed by Karl Ernst von Baer.
He noted that embryos never pass through the adult stages of other animals.
- The similarity of bone structure in the forelimbs of many
vertebrates is an example of: (2018)
a. Homology
b. Analogy
c. Convergent evolution
d. Adaptive radiation
Chapter 6 / Grade 12 evolution / page 114-115-summary
a. Homology
NCERT
Homology indicates common ancestry. Other examples are vertebrate hearts or brains (114)
Homology is based on divergent evolution whereas
analogy refers to a situation exactly opposite. (115)
Homology is accounted for by the idea of branching descent (summary)
- Among the following sets of examples for divergent evolution,
select the incorrect option: (2018)
a. Forelimbs of man, bat and cheetah
b. Heart of bat, man and cheetah
c. Brain of bat, man and cheetah
d. Eye of octopus, bat and man
Chapter 6 / Grade 12 evolution / page 115
d. Eye of octopus, bat and man
NCERT
Eye of octopus, bat and man - example of convergent evolution
Hence, analogous structures are a result of convergent evolution - different structures evolving for the same function and hence having
similarity.
Other examples of analogy are the eye of the octopus and of mammals or the flippers of Penguins and Dolphins.
- Analogous structures are a result of: (2016 - I)
a. Divergent evolution
b. Convergent evolution
c. Shared ancestry
d. Stabilising selection
Chapter 6 / Grade 12 evolution / page 115
b. Convergent evolution
Hence, analogous structures are a result of convergent evolution - different structures evolving for the same function and hence having
similarity.
Other examples of analogy are the eye of the octopus and of mammals or the flippers of Penguins and Dolphins.
- Which of the following structures are homologues to the wing of a bird? (2016 - I)
a. Dorsal fin of a Shark
b. Wing of a Moth
c. Hind limb of Rabbit
d. Flipper of Whale
Chapter 6 / Grade 12 evolution / page 114-115
d. Flipper of Whale
NCERT
Homology is based on divergent evolution whereas
analogy refers to a situation exactly opposite.
Wings of butterfly and of birds look alike.
They are not anatomically similar structures though they perform
similar functions.
TRY TO UNDERSTAND THIS QUESTION A LITTLE MORE
- The wings of a bird and the wings of an insect are: (2015 Re)
a. Analogous structures and represent convergent evolution
b. Phylogenetic structures and represent divergent evolution
c. Homologous structures and represent convergent evolution
d. Homologous structures and represent divergent evolution
Chapter 6 / Grade 12 evolution / page 115
a. Analogous structures and represent convergent evolution
NCERT
Wings of butterfly and of birds look alike.
They are not anatomically similar structures though they perform
similar functions.
Hence, analogous structures are a result of convergent evolution - different structures evolving for the same function and hence having
similarity.
Other examples of analogy are the eye of the octopus and of mammals or the flippers of Penguins and Dolphins
STILL CHECK THIS IN NCERT
- Industrial melanism is an example of: (2015 Re)
a. Natural selection
b. Mutation
c. Neo Lamarckism
d. Neo Darwinism
Chapter 6 / Grade 12 evolution / page 115
a. Natural selection
NCERT
Another interesting observation supporting evolution by
natural selection comes from England.
In a collection of moths made in 1850s, i.e., before industrialisation set in, it was observed that there were more white-winged moths on trees than dark-winged or melanised moths.
However, in the collection carried out from the same area, but after
industrialisation, i.e., in 1920, there were more dark-winged moths in
the same area, i.e., the proportion was reversed.
LOOK IN DEPTH
- Forelimbs of cat, lizard used in walking; forelimbs of whale used in swimming and forelimbs of bats used in flying are an example of: (2014)
a. Convergent evolution
b. Analogous organs
c. Adaptive radiation
d. Homologous organs
Chapter 6 / Grade 12 evolution / page 115
d. Homologous organs
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- Which one of the following are analogous structures? (2014)
a. Flippers of dolphin and legs of horse
b. Wings of bat and wings of pigeon
c. Gills of prawn and lungs of man
d. Thorns of Bougainvillea and tendrils of Cucurbita
Chapter 6 / Grade 12 evolution / page 115
b. Wings of bat and wings of pigeon
c. Gills of prawn and lungs of man
NCERT
Hence, analogous structures are a result of convergent evolution - different structures evolving for the same function and hence having
similarity
- The process by which organisms with different evolutionary history evolve similar phenotypic adaptations in response to a common environmental challenge, is called: (2013)
a. Adaptive radiation
b. Natural selection
c. Convergent evolution
d. Non-random evolution
c. Convergent evolution
CHECK THIS QUESTION OUT!!
- The eye of octopus and eye of cat show different patterns of structure, yet they perform similar function. This is an example of: (2013)
a. Analogous organs that have evolved due to divergent evolution
b. Homologous organs that have evolved due to convergent evolution
c. Homologous organs that have evolved due to divergent evolution
d. Analogous organs that have evolved due to convergent evolution
Chapter 6 / Grade 12 evolution / page 115
d. Analogous organs that have evolved due to convergent evolution
NCERT
Hence, analogous structures are a result of convergent evolution - different structures evolving for the same function and hence having
similarity.
Other examples of analogy are the eye of the octopus and of mammals or the flippers of Penguins and Dolphins.
- Match the following: (2021)
List-I List-II
(A) Adaptive radiation (i) Selection of resistant
varieties due to
excessive use of
herbicides and
pesticides
(B) Convergent evolution (ii) Bones of forelimbs in
Man and Whale
(C) Divergent evolution (iii) Wings of Butterfly and
Bird
(D) Evolution by anthropogenic action (iv) Darwin Finches
Choose the correct answer from the options given below.
a. A-iii B-ii C-i D-iv
b. A-ii B-i C-iv D-iii
c. A-i B-iv C-iii D-ii
d. A-iv B-iii C-ii D-i
Chapter 6 / Grade 12 evolution / page 114-116
d. A-iv B-iii C-ii D-i
(A) Adaptive radiation - (iv) Darwin Finches
(B) Convergent evolution - (iii) Wings of Butterfly and Bird
(C) Divergent evolution - (ii) Bones of forelimbs Man and Whale
(D) Evolution by anthropogenic action - (i) Selection of resistant
varieties due excessive use of herbicides and pesticides
NCERT
A. During his journey Darwin went to Galapagos Islands. There he observed an amazing diversity of creatures. Of particular interest, small black birds later called Darwin’s Finches amazed him. (116)
B. Wings of butterfly and of birds look alike. They are not anatomically similar structures though they perform similar functions. Hence, analogous structures are a result of convergent evolution - different structures evolving for the same function and hence having similarity. (115)
C. Cheetah and human (all mammals) share similarities in the pattern of bones of forelimbs (Figure 6.3b). Though these forelimbs perform different functions in these animals, they have similar anatomical structure – all of them have humerus, radius, ulna, carpals, metacarpals and phalanges in their forelimbs. Hence, in these animals, the same structure developed along different directions due to adaptations to different needs. This is divergent evolution and these structures are homologous. (114)
ADD THE IMAGE
D. Similarly, excess use of herbicides, pesticides, etc., has only resulted in selection of resistant varieties in a much lesser time scale. This is also true for microbes against which we employ antibiotics or drugs against eukaryotic organisms/cell. Hence, resistant organisms/cells are appearing in a time scale of months or years and not centuries. These are examples of evolution by anthropogenic action. This also tells us that evolution is not a directed
process in the sense of determinism. It is a stochastic process based on chance events in nature and chance mutation in the organisms. (116)
- The phenomenon of evolution of different species in a given geographical area starting from a point and spreading to other habitats is called- (2020-Covid)
a. Co-evolution
b. Natural selection
c. Adaptive radiation
d. Saltation
Chapter 6 / Grade 12 evolution / page 117
c. Adaptive radiation
NCERT
This process of evolution of different species in a given geographical area starting from a point and literally radiating to other areas of geography (habitats) is called adaptive radiation
- Natural selection where more individuals acquired specific character value other than the mean character value, leads to:
a. Random change
b. Stabilizing change
c. Directional change
d. Disruptive change
Chapter 6 / Grade 12 evolution / page 121
c. Directional change
NCERT
directional change
(more individuals acquire value other than the mean character value)
- Variations caused by mutation, as proposed by Hugo de Vries are (2019)
a. Random and directional
b. Random and directionless
c. Small and directional
d. Small and directionless
b. Random and directionless
NCERT
In the first decade of twentieth century, Hugo deVries based on his work on evening primrose brought forth the idea of mutations – large difference arising suddenly in a population.
He believed that it is mutation which causes evolution and not the minor variations (heritable) that Darwin talked about.
Mutations are random and directionless
- 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 weight
from 2 to 2.5 kg or 4.5 to 5 kg die.
Which type of selection process is taking place? (2019)
a. Directional Selection
b. Stabilizing Selection
c. Disruptive Selection
d. Cyclical Selection
Chapter 6 / Grade 12 evolution / page 121
b. Stabilizing Selection
NCERT
Natural selection can lead to stabilisation (in
which more individuals acquire mean character value),
- According to Hugo de Vries, the mechanism of evolution is:
(2018)
a. Multiple step mutations
b. Saltation
c. Phenotypic variations
d. Minor mutations
Chapter 6 / Grade 12 evolution / page 119
b. Saltation
NCERT
Evolution for Darwin was gradual while deVries believed
mutation caused speciation and hence called it saltation
(single step large mutation).
- Artificial selection to obtain cows yielding higher milk output represents: (2017-Delhi)
a. Stabilizing selection as it stabilizes 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. Stabilizing followed by disruptive as it stabilizes the population to produce higher yielding cows.
b. Directional as it pushes the mean of the character in one direction.
NCERT
directional change
(more individuals acquire value other than the mean character value
CHECK THIS QUESTION OUT
- According to Darwin, the organic evolution is due to: (2013)
a. Reduced feeding efficiency in one species due to the presence of interfering species
b. Intraspecific competition
c. Interspecific competition
d. Competition within closely related species
c. Interspecific competition
CHECK THIS QUESTION OUT
- The factor that leads to Founder effect in a population is: (2021)
a. Genetic recombination
b. Mutation
c. Genetic drift
d. Natural selection
Chapter 6 / Grade 12 evolution / page 121
c. Genetic drift
NCERT
There would be a gene flow if this gene migration, happens multiple times.
If the same change occurs by chance, it is called genetic drift.
Sometimes 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.
- A gene locus has two alleles A and 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? (2019)
a. 0.36(AA); 0.48(Aa); 0.16(aa)
b. 0.16(AA); 0.24(Aa); 0.36(aa)
c. 0.16(AA); 0.48(Aa); 0.36(aa)
d. 0.16(AA); 0.36(Aa); 0.48(aa)
c. 0.16(AA); 0.48(Aa); 0.36(aa)
CHECK THIS QUESTION - COULDN’T FIND IT
- In Hardy-Weinberg equation, the frequency of heterozygous individual is represented by:
(2016 - II)
a. pq
b. q2
c. p2
d. 2pq
d. 2pq
Similarly of aa is q2, of Aa 2pq.
Hence, p2+2pq+q2=1. This is a binomial expansion of (p+q)2
LOOK AT IN DEPTH
.
- Genetic drift operates in: (2016 - II)
a. Non-reproductive population
b. Slow reproductive population
c. Small isolated population
d. Large isolated population
c. Small isolated population
COULDN’T FIND THIS
- Which is the most common mechanism of genetic variation in the population of a sexually reproducing organism? (2015)
a. Genetic drift
b. Recombination
c. Transduction
d. Chromosomal aberrations
Chapter 6 / Grade 12 evolution / page 121 (MAYBE THIS IS THE ANS.)
DIDN’T WRITE IT DOWN IN NCERT
b. Recombination
NCERT
A critical analysis makes us believe that variation due to mutation or variation due to recombination during gametogenesis, or due to gene flow or genetic drift results in changed frequency of genes and alleles in future generation.
- A population will not exist in Hardy-Weinberg equilibrium if: (2015)
a. There is no migration
b. The population is large
c. Individuals mate selectively
d. There are no mutations
c. Individuals mate selectively
COULDN’T FIND IT NCERT
- The following graph depicts changes in two populations (A and B) of herbivores in a grassy field. A possible reason for these changes is that: (2015) (insert page)
a. Population A produced more offspring than population B
b. Population A consumed the members of population B
c. Both plant populations in this habitat decreased
d. Population B competed more successfully for food than
population A
d. Population B competed more successfully for food than
population A
CHECK THIS IN NCERT
DIDN’T WRITE IT DOWN
- 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: (2014)
a. 0.7
b. 0.4
c. 0.5
d. 0.6
d. 0.6
COULD’T FIND IT IN NCERT
DIDN’T WRITE IT DOWN
UNDERSTAND THE QUESTION
- Variation in gene frequencies within populations can occur by chance rather than by natural selection. This is referred to as: (2013)
a. Genetic load
b. Genetic flow
c. Genetic drift
d. Random mating
Chapter 6 / Grade 12 evolution / page 121
c. Genetic drift
NCERT
There would be a gene flow if this gene migration, happens multiple times. If the same change occurs by chance, it is called genetic drift.
UNDERSTAND THE QUESTION
- The tendency of population to remain in genetic equilibrium may be disturbed by: (2013)
a. Lack of random mating
b. Random mating
c. Lack of migration
d. Lack of mutations
a. Lack of random mating
COULD’T FIND IT IN NCERT
DIDN’T WRITE IT DOWN
UNDERSTAND THE QUESTION
- A Hominid fossil discovered in Java in 1891, now extinct, having cranial capacity of about 900 cc was: (2020-Covid)
a. Neanderthal man
b. Homo sapiens
c. Australopithecus
d. Homo erectus
Chapter 6 / Grade 12 evolution / page 124
d. Homo erectus
NCERT
Homo erectus had a large brain around 900cc.
- Match the hominids with their correct brain size :
A. Homo habilis i. 900 cc
B. Homo neanderthalensis ii. 1350 cc
C. Homo erectus iii. 650-800 cc
D. Homo sapiens iv. 1400 cc
Select the correct option. (2019)
(A) (B) (C) (D) a. (iii) (i) (iv) (ii) b. (iii) (ii) (i) (iv) c. (iii) (iv) (i) (ii) d. (iv) (iii) (i) (ii)
Chapter 6 / Grade 12 evolution / page 124-125
(A) (B) (C) (D)
c. (iii) (iv) (i) (ii)
A. Homo habilis - iii. 650-800 cc
B. Homo neanderthalensis - iv. 1400 cc
C. Homo erectus - i. 900 cc
D. Homo sapiens - ii. 1350 cc
NCERT
A. This creature was called the first human-like being the hominid and was called Homo habilis. The brain capacities were between
650-800cc.
B. The Neanderthal man with a brain size of 1400cc lived in near east and central Asia between 1,00,000-40,000 years back.
C. Fossils discovered in Java in 1891 revealed the next stage, i.e.,
Homo erectus about 1.5 mya. Homo erectus had a large brain around 900cc.
D. COULDN’T FIND IT
- The chronological order of human evolution from early to the recent is: (2016 - II)
a. Ramapithecus-Homo habilis-Australopithecus -Homo erectus
b. Australopithecus-Homo habilis-Ramapithecus -Homo erectus
c. Australopithecus-Ramapithecus-Homo habilis -Homo erectus
d. Ramapithecus-Australopithecus-Homo habilis -Homo erectus
Chapter 6 / Grade 12 evolution / page 124-125
d. Ramapithecus-Australopithecus-Homo habilis -Homo erectus
NCERT
About 15 mya, primates called Dryopithecus and Ramapithecus were
existing. They were hairy and walked like gorillas and chimpanzees.
Ramapithecus was more man-like while Dryopithecus was more
ape-like. Few fossils of man-like bones have been discovered in Ethiopia and Tanzania (Figure 6.11).
Add the image
These revealed hominid features leading to the belief that about 3-4 mya, man-like primates walked in eastern Africa. They were probably not taller than 4 feet but walked up right. Two mya, Australopithecines probably lived in East African grasslands. Evidence
shows they hunted with stone weapons but essentially ate fruit. Some of the bones among the bones discovered were different. This creature was called the first human-like being the hominid and was called Homo habilis. 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., Homo erectus about 1.5 mya. Homo erectus had a large brain around 900cc. Homo erectus probably ate meat.
- Which of the following had the smallest brain capacity?
(2015 Mains)
a. Homo neanderthalensis
b. Homo habilis
c. Homo erectus
d. Homo sapiens
Chapter 6 / Grade 12 evolution / page 124-125
b. Homo habilis
NCERT
This creature was called the first human-like being the hominid and was called Homo habilis. The brain capacities were between
650-800cc.
NOTE
A. Homo habilis - iii. 650-800 cc
B. C. Homo erectus - i. 900 cc
C. Homo sapiens - ii. 1350 cc
D. Homo neanderthalensis - iv. 1400 cc
