Nootan solutions for बायोलॉजी [अंग्रेजी] कक्षा १२ आयसीएसई chapter 8 - Evidences and Theories of Biological Evolution [Latest edition]

The idea of common descent came to Darwin by his observations on ______.

The wings of a bird and the fore legs of a horse are ______.

Which of the following plays a very negligible role in evolution?

Analogous organs are those which are ______.

Appearance of ancestral characters in new borns such as tails, multiple mammae, etc., are ______.

Evolution:

The gill slits of reptile and bird embryos are ______.

The best evidence for a common origin of all life is ______.

The Galapagos Islands are located near to the ______.

The greatest adaptive radiation of the animal kingdom occurred during the ______.

Extensive adaptive radiations have usually followed in the wake of mass extinctions mainly because ______.

The fossil record offers direct evidence for common descent because you can ______.

DNA nucleotide differences between organisms:

The many species of Galapagos finches were each adapted to eating different foods. This is an example of ______.

Which of the following is mismatched?

Continental drift helps explain the occurrence of ______.

Which of the following best describes strata?

Which of the following groups of birds is correctly matched with the islands on which these birds underwent an adaptive radiation?

For an adaptive radiation to be successful ______.

Evolution of the pandas thumb and evolution of the mammalian ear ossicles are examples of ______.

The crisis that drastically reduced the diversity of dinosaurs and other reptiles occurred ______.

Which of the following groups evolved from reptiles?

Which of the following contributed to evolution of the several species of finches on the Galapagos islands?

All the finches on the Galapagos islands ______.

A biogeographical evidence in favour of organic evolution is provided by ______.

Which one of the following is homologous to the wing of a bat?

Which of the following structures are analogous?

Which of the following is called as the connecting link between Reptiles and Birds?

Palaeontological evidences for evolution refer to the ______.

The bones of forelimbs of whale, bat, cheetah and man are similar in structure, because ______.

Name the scientist who propounded the ‘recapitulation theory’:

Analogous organs arise due to ______.

Darwin believed that a giraffe has a long neck because ______.

Many bacteria are now resistant to penicillin, because ______.

Natural selection is best defined as occurring when the environment causes ______.

Reproduction ______.

Natural selection may occur when there are ______.

Sickle-cell anaemia first appeared in Asia, the Middle East, and Africa. The causative allele entered the population of the United States when people were forcibly brought over from Africa prior to the Civil War. In microevolutionary terms, this is a case of ______.

Directional selection ______.

The ideas of Hutton and Lyell that Darwin incorporated into his theory concerned ______.

Which of the following is not a fact or inference of natural selection?

In the case of the English peppered moth, which of the following occurred?

Darwin’s theory, as presented in ‘The Origin of Species’, mainly concerned ______.

Which of the following labels best fits Darwin?

Which of the following persons is incorrectly matched with a term or idea?

Selection acts directly on ______.

As a mechanism of microevolution; natural selection can be most closely equated with ______.

Most of the variation we see in coat colouration and pattern in a population of wild mustangs in any generation are probably due to ______.

The largest unit in which gene flow is possible is a ______.

Some species of Anopheles mosquito live in brackish water, some in running fresh water, and others in stagnant water. What type of reproductive barrier is most obviously separating these different species?

The reproductive barrier that maintains the species boundary between horses and donkeys is ______.

Which of the following did not support the theory of evolution?

Which of the following is not an important element of Darwin’s theory of evolution?

Which of the following scientists proposed a theory of evolution that was based on inheritance of acquired characteristics?

All of the following except ______ are sources of change in the genome.

All of the following are sexual sources of genetic variation except:

According to the theory of acquired inheritance ______.

Why was it helpful to Darwin to learn that Lyell thought the earth was very old?

Allopatric but not sympatric speciation requires ______.

Male moths recognize females of their species by sensing chemical signals called pheromones. This is an example of ______.

Which of the following is a premating isolating mechanism?

The biological definition of a species depends on ______.

When a population is small, there is a greater chance of ______.

Which of the following is necessary to natural selection?

The continued occurrence of sickle-cell disease in parts of Africa with malaria is due to ______.

A human population has a higher-than-usual percentage of individuals with a genetic disease. The most likely explanation is ______.

The offspring of better-adapted individuals are expected to make up a larger proportion of the next generation. The most likely explanation is ______.

Which of the following is the form of selection that operates in most natural populations?

Which of the following normally occurs in most species?

Which of the following is not a means by which genetic variation can occur within an individual organism?

Fitness is an important concept in natural selection. Fitness is most properly a property of ______.

Random breeding within a deme is referred to as ______.

Which of the following was most likely a proponent of the hypothesis of acquired traits?

Unrelated species that have achieved the same levels of biological improvement belong to the same ______.

Which of the following is a way by which a species can arise and live in sympatry with the species from which it evolved?

Which of the following is not a prezygotic isolating mechanism?

The evolutionary importance of ______ was apparent to Darwin, but not to Linnaeus.

According to Lamarck, a giraffe has a long neck because ______.

The unit of natural selection is the ______.

Charles Darwin’s book ‘On the Origin of Species by Means of Natural Selection,’ was first published in ______.

The struggle for existence is a consequence of ______.

Populations of peppered moths (Biston betularia) of England changed from 1% dark and 99% grey individuals to 99% dark and 1% light individuals between 1848 and 1898. The selective agent causing the change was ______.

The unit of evolution is now known to be the ______.

The total collection of genes, at any one time, in a unit of evolution is called the ______.

Genetic drift, or changes in allelic frequency due to chance factors, occurs in populations that are very ______.

Natural selection is best defined as occurring when the environment causes ______.

Members of biologic species are potentially able to ______.

A prezygotic isolating mechanism prevents successful ______.

A postzygotic isolating mechanism prevents successful ______.

In allopatric speciation the initial barrier to gene flow is ______.

Sympatric speciation occurs most commonly in ______.

Of all the taxa the one that exists in nature as a biologically cohesive unit is the ______.

The theory of natural selection was put forth by ______.

One of the revolutionary concepts in biology was projected by Charles Darwin in the Origin of the Species and has been discussed as ______.

Which one of the following is not associated with the theory of Charles Darwin?

The use and disuse principle of evolution was proposed by ______.

In formulating the theory of evolution by natural selection, Charles Darwin was greatly influenced by ______.

The idea of natural selection as the fundamental process of evolutionary change was reached ______.

Darwin’s explanation of the way in which evolution occurs is that ______.

Successful adaptation simply means ______.

Which statement is correct regarding Biston betularia, a species of moth found in England during the late 19th century?

The descendant of colewort is ______.

Plant breeding programmes are the examples of ______.

(p + q)² = p² + 2pq = q² = 1 represent ______.

Which type of selection explains industrial melanism observed in moth, Biston bitularia?

Who of the following proposed the mutation theory of evolution?

Importance of mutation in organic evolution is ______.

Ontogeny repeats phylogeny is also known as ______.

Homologous structures are similar in ______.

______ era is popularly known as the age of mammals.

Thorns of Bougainvillea and the tendrils of Cucurbita are ______ structures.

The study of patterns of distribution of organisms in different parts of the earth is called ______.

Darwin could not explain completely the mechanisms of evolution, because he was ignorant of the mechanisms of ______.

For evolution to take place, a population must have both ______ and ______.

Populations segregated by a geographic barrier are known as ______ populations.

The process that prevents interbreeding between related groups of living organism is called ______.

The evolution of a species can be considered as the sum total of its adaptive changes preserved by ______.

An important addition to Darwin’s work was the discovery that ______ occur, providing a source for the observed inherited variations.

Natural selection operates only on ______ traits.

The branch of biology that emerged from the synthesis of darwinian evolution and mendelian genetics is ______.

A group of individuals with the potential to interbreed is a ______ whereas a group of individuals with a high probability of interbreeding is a ______.

Populations with overlapping geographic ranges are known as ______ populations in the areas of overlap.

When the environment causes a change in the gene pool by controlling reproductive success according to genotype, it is called ______.

A change in the gene pool of a small population due to chance is called ______.

______ and ______ jointly proposed the Theory of Natural Selection.

Rapid speciation occurs by ______ and ______.

State whether the following statement is true or false.

The existence of rudimentary limb structures in snakes constitutes an argument for special creation.

State whether the following statement is true or false.

Natural selection is a process which aims at the improvement of the unfit.

State whether the following statement is true or false.

Vestigial organs are those organs which have disappeared from the body.

State whether the following statement is true or false.

The theory of recapitulation proposes that embryonic development repeats the evolutionary history of their ancestors.

State whether the following statement is true or false.

Somatic variations form the basis of evolution.

State whether the following statement is true or false.

Organic evolution is the process by which complex organisms gave rise to simple inorganic materials in course of time.

State whether the following statement is true or false.

Use and disuse is the basic postulate of Lamarckism.

State whether the following statement is true or false.

The unit of evolution now recognized is the population.

State whether the following statement is true or false.

Industrial melanism is one of the important examples of natural selection.

State whether the following statement is true or false.

Mutation, selection and genetic drift are three important forces which are responsible for evolutionary changes.

Name any two vestigial structures in human body.

Which technique is mostly used to determine the age of fossils?

Name an egg-laying organism which represents a connecting link between mammals and reptiles.

What kind of evidence is afforded by the Darwin’s finches in support of organic evolution?

If you discovered a fossil of a bird with scales on the body and teeth in the beak, what would you conclude about its position in the animal kingdom?

Name a fossil which represents a missing link between birds and reptiles. Give two avian characters of this fossil.

Classify the following into analogous and homologous organs:

1. Trunk of an elephant and hand of chimpanzee
2. Wing of a bat and wing of an insect
3. Mouth parts of insects
4. Wing of a bat and wing of a bird
5. Ginger and sweet potato
6. Human arms and foreleg of cow
7. Eyes of Octopus and mammals
8. Thorns of Bougainvillea and tendrils of curcubits
9. Flippers of penguins and dolphins
10. Sweet potato tubers and potato tubers
11. Forelimbs of cheetah and mammals
12. Wings of butterflies and birds
13. Forelimbs of whales and mammals
14. Forelimbs of whales and bats
15. Wing of bat and flipper of whale
16. Wing of butterfly and flipper of whale
17. Flipper of whale and wing of bird
18. Vertebrate hearts

Where are the Galapagos Islands are located?

What is phylogeny?

Peripatus is a connecting link between which of the two phyla.

Mention any one striking similarity that is found in the embryos of all vertebrates at an early stage. What is it indicative of?

What is meant by homologous organs? Give one example.

What is meant by analogous organs? Give one example from animals.

What is the significance of Archaeopteryx in organic evolution?

Taking any one example from human body explain what is meant by vestigial organs.

Tell any two structural features in vertebrate embryos that support organic evolution.

How do you consider tendrils of cucumber and thorns of Bougainvillea as homologous structures?

Identify the examples of homologous structures from the following:

1. Vertebrate hearts.
2. Thorns in Bougainvillea and tendrils of Cucurbita.
3. Food storage organs in sweet potato and potato.

Name any two temporary embryonic structures in vertebrates which provide evidence for evolution.

Name the type of evolution that has resulted in the development of structures like wings of butterfly and bird. What are such structures called?

Why are analogous structures a result of convergent evolution?

When can adaptive radiation be referred to as convergent evolution? Cite an example.

Rearrange the following in increasing order of evolution:

Gnetales; Ferns; Zosterophyllum; Ginkgo.

What does the comparison between the eyes of Octopus and those of mammals say about their ancestry and evolution?

Cite an example where more than one adaptive radiations have occurred in an isolated geographical area. Name the type of evolution your example depicts and state why it is so named.

State the significance of the study of fossils in evolution.

Name the connecting links between the phyla Annelida and Arthropoda.

Name the connecting links between the class Reptilia and Aves.

How do we compute the age of a fossil?

What is adaptive radiation?

Archaeopteryx is connecting link of which classes?

Define fossil.

Who proposed the ‘Theory of Origin of Species by Natural Selection’ and in which year?

Name the ship on which Darwin was appointed as a naturalist.

Who wrote the book ‘Philosophic Zoologique’ in 1809?

What is the main cause of allopatric speciation?

Name the three key factors of the modern concept of organic evolution.

Name the famous experimenter who worked towards non-acceptance of Lamarck’s theory. Name the organism on which he experimented.

What are the various causes of variation?

Name the phenomenon by which dark coloured moth originated from grey coloured moth.

Which concept is attributed to Charles Darwin?

Who proposed the ‘Theory of Inheritance of Acquired Characters’ and in which year?

The book ‘Origin of Species’ was published in which year?

Who wrote the book ‘Origin of Species’?

Write in one sentence the main idea in Lamarck’s theory about evolution.

Darwin’s theory is popularly known as ‘theory of natural selection’. How is Lamarck’s theory known as?

Name the naturalist who put forward the theory of natural selection along with Darwin.

 Define the term of species.

Define the following term:

Speciation

Write the full form of G-6-PD.

Name the scientist associated with mutation theory.

Define the term reproductive isolation.

What is the cause of sickle-celled anaemia?

Which concept is attributed to Charles Darwin?

Narrate one famous experiment which disproved Lamarck’s theory.

What is the unit of natural selection?

Name any two breeds of wild rock pigeon that have been developed through artificial selection.

Quote any two descendants of the plant colewort developed through artificial selection.

Mention any one major source of variation in a sexually reproduced offspring.

Name the inbuilt mechanism that preserves the integrity of a species by preventing hybridization.

What causes speciation according to Hugo de Vries?

Mention the key concept about the mechanism of biological evolution/speciation according to de Vries.

Mention the key concept about the mechanism of biological evolution/speciation according to Darwin.

How does ‘fitness’ of a population help in evolution?

Prior to industrialization there were far more white-winged moths on trees than melanised moths in England. However, after industrialization the distribution pattern of these two kinds of moths reversed. What does the above observation indicate? Explain giving reasons.

Name the biological process that enables continuity of species.

State the best-known contribution of Hugo de Vries

What is ‘saltation’ according to de Vries?

List any four factors which affect genetic equilibrium.

What does the following equation represent? Explain:

p² + 2pq + q² = 1.

Name the two key concepts of Darwinian Theory of Evolution.

Write three factors by which Hardy-Weinberg equilibrium can be affected.

State a reason for the increased population of dark coloured moths coinciding with the loss of lichens (on tree barks) during industrialization period in England.

How does the Monarch butterfly defend itself from predators? Explain.

Write the basis of origin of variations in organisms as described by hugo de vries.

Among the five factors that are known to effect Hardy Weinberg equilibrium, two factors are gene flow and genetic drift. What are the other three factors?

“Migration may enhance or blurr the effects of selection”. Comment.

Give any two striking similarities in the structure of embryos of all vertebrates.

What is the significance of similarities between the structure of embryos of all vertebrates in the concept of organic evolution?

How does phylogeny help in building broad historical sequence of biological evolution? Explain with the help of the example of horse.

What are the evidences of organic evolution?

How comparative anatomy of animals give evidences of organic evolution?

How embryology of animals give evidences of organic evolution?

What is a biogeographic map?

Locate Galapagos islands in the world atlas. What was unique about these islands which helped Darwin arrive at significant concepts regarding evolution?

How do data from the fossil record support the concept that organisms are related through common descent? Explain.

How do data from biogeography support he concept of common descent?

How do data from comparative anatomy support the concept of common descent? Explain why vertebrate forelimbs are similar despite different functions.

What is a vestigial organ?

How does the presence of vestigial organs support the doctrine of organic evolution?

Archaeopteryx is a connecting link between reptiles and birds. Justify the statement by giving two characteristics of each group.

The wing of bat is said to be homologous to the wing of a bird and analogous to the wing of an insect.

Explain the following term:

Palaeontology

Explain the following term:

Vestigial organs

Explain the following term:

Atavism

Explain the following term:

Geological time scale

Explain the following term:

Homologous organs

State the following:

Theory of recapitulation

Explain the following term:

Darwin’s finches

How does palaeontological evidence support the theory of organic evolution? Explain with an example.

What are homologous organs?

How do homologous organs help in providing evidence for organic evolution?

State three differences between homologous and analogous organs and give an example of each.

What are the important changes in the evolution of the modern horse from the Eohippus (ancestral horse)?

Explain adaptive radiation with the help of a suitable example.

Explain any three molecular (genetic) evidences in favour of organic evolution.

Write short note on neo-Darwinism.

Write a short note on reproductive isolation.

Write a short note on allopatry.

Write a short note on sympatry.

Write a short note on genetic drift.

Write a short note on mutation.

Write a short note on variations.

Write a short note on Hardy, Weinberg’s principle.

Write a short note on Founder’s effect.

Explain the elongation of giraffe’s neck according to the theories of Lamarck.

Explain the elongation of giraffe’s neck according to the theories of Darwin.

State the main features of Darwin’s Theory of Natural Selection.

Persons suffering from G-6 PD deficiency are resistant of malaria, Explain.

Who was the originator of the ‘Theory of Natural Selection’?

Explain the evolution of species by the Theory of Natural Selection.

Taking industrial melanism as an example, explain the process of natural selection.

Explain the basic postulates of Darwinism.

What is sickle cell anaemia?

Why has natural selection not eliminated sickle cell anaemia?

Explain the resistance of mosquitoes to pesticides such as DDT.

Name and define the three types of natural selection.

Persons suffering from sickle cell anaemia are at an advantage in Malaria infected areas. Explain.

Give an account of Lederberg’s replica plating experiment to show the genetic basis of adaptation.

What is adaptive radiation?

When can adaptive radiation be referred to as convergent evolution? Cite an example.

Differentiate between Directional natural selection and Disruptive natural selection. 

List any three drawbacks of Darwinism.

What is reproductive isolation?

What is the significance of reproductive isolation?

Explain industrial melanism.

Explain the evolution of the long neck of giraffe according to Charles Darwin. 

In the Hardy-Weinberg equation, the frequency of heterozygous individuals is represented by ______.

Genetic drift operates in a ______.

Which of the following is not a vestigial organ of human beings?

Who proposed the recapitulation theory?

Gene migration is also called ______.

Which of the following options is NOT a feature of the modern synthetic theory of evolution?

Assertion: Genome similarity and universal genetic code are examples of molecular (genetic) evidences of evolutions.

Reason: Molecular evidences are based on fossils found under the earth’s strata.

Explain adaptive radiation with the help of a suitable example.

Phenylketonuria occurs in the population with a frequency of 1 in 2000. Calculate the frequency of the carrier genotype.

What do you understand by a species? Outline the ways in which new species arise.

How does a population become ‘founders’ of a new species?

List 10 modern-day animals and using the internet resources link it to a corresponding ancient fossil. Name both.

Describe one example of adaptive radiation.

Using various resources such as your school library or the internet and discussions with your teacher, trace the evolutionary stages of any one animal say horse.

Explain antibiotic resistance observed in bacteria in light of Darwinian selection theory.

Attempt giving a clear definition of the term species.

Your friend Ram who had gone to the City Hospital for collecting his father’s medical report witnessed a crowd of people outside the maternity ward of the hospital who were curious to see Mrs. Sharma’s new born child who was borne with a small tail. He overheard some people saying that it was an ill omen and indicated towards arrival of some natural disaster in Mr. Sharma’s home. As a student of Biology how will you explain this biological phenomenon to the people gathered there and help them alleviate their tears of ill omen.

While on a business trip to Mumbai, you received a call from your neighbour Raghav informing that your father complained of severe pain in his abdomen in the midnight and had to be rushed to the hospital. The doctors have diagnosed the problem and suggested immediate surgery to remove the swollen appendicitis. Your father who maintains a healthy lifestyle and rarely visits any doctor is terrified at the thought of being operated upon. As a student of Biology how will you console your father and explain him the medical condition to help him overcome his tear of surgery.

Since the origin of life on Earth, there were five episodes of mass extinction of species.

1. How is the ‘Sixth Extinction’, presently in progress, different from the previous episodes?
2. Who is mainly responsible for the ‘Sixth Extinction’?
3. List important points that can help to overcome this disaster.

My friend Ashok lives in a prosperous village. The community workers usually use pesticides, like DDT indiscriminately and in higher doses to kill the mosquitoes, inhabiting near the ponds, and in the fields. One day, when Ashok visited his village, his father told him that earlier DDT was very effective in controlling mosquitoes population but now it is not so effective. What reason and remedy would you suggest to the villagers?

A group of pesticide sprayers were worried about their profession when all the mosquitoes got exterminated. How can you explain that such an anxiety was based on ignorance?

You have studied the story of Peppermoths in England. Had the industries been removed, what impact could it have had on the moth population? Discuss.

Differentiate between Biogeography and palaeontology.

Differentiate between connecting links and the missing links.

Differentiate between divergent evolution and convergent evolution with one example for each.

Differentiate between Convergent and divergent evolution.

Differentiate between Genetic drift and gene migration.

Differentiate between Geographical and reproductive isolation.

State three differences between homologous and analogous organs and give an example of each.

Differentiate between Meristic and substantive variations.

Differentiate between Natural selection and artificial selection.

Differentiate between Ontogeny and Phylogeny.

Differentiate between Short-term and long-term adaptations.

Differentiate between Somatogenic and blastogenic variations.

Differentiate between Vestigial organ and atavistic organ.