Students should refer to Human Evolution ICSE Class 10 Biology Board Exam Questions provided below with solutions. These will help the students to understand the type of questions which have been asked in previous year examinations and the type of solutions which the student should give to get good marks. You should also refer to ICSE Class 10 Biology Sample papers for more practice
ICSE Class 10 Biology Human Evolution Important Questions
Students should learn the important questions and answers given below for Chapter Human Evolution in Biology for ICSE Class 10. These board questions are expected to come in the upcoming exams. Students of ICSE Class 10th should go through the Important questions and answers ICSE Class 10 Biology which will help them to get more marks in exams.
Human Evolution ICSE Class 10 Biology Board Exam Questions
Human Evolution ICSE Class 10 Biology
Question. Fill in the blanks and rewrite the complete statements :
1. ___________ favours different genes or gene combinations in individuals of different populations, occupying ____________ .
Natural selection favours different genes or gene combinations in individuals of different populations, occupying different niche.
2. Homo sapiens evolved from _____________ .
Homo sapiens evolved from Homo erectus.
3. _____________ occurs in a large and widely distributed population.
Geographical speciation occurs in a large and widely distributed population.
4. The range of cranial capacities in the following ancestral forms were :
a. Homo sapiens sapiens – ________________
Homo sapiens sapiens – 1450 – 1600 cm3
b. Homo erectus – ________________
Homo erectus – 800 – 1125 cm3
c. Australopithecus – ________________
Australopithecus – 450 – 600 cm3
d. Cro -Magnon – ________________
Cro-Magnon – 1450 – 1600 cm3
e. Homo habilis – ________________
Homo habilis – 680 – 735 cm3
5. Voyage by Darwin on the ship ___________ provided him the opportunity to observe great diversity in organisms.
Voyage by Darwin on the ship HMS Beagle provided him the opportunity to observe great diversity in organisms.
6. The common ancestor for ape and man is named ___________ .
The common ancestor for ape and man is named Dryopithecus.
7. ___________ proposed theory of natural selection for the origin of species.
Charles Robert Darwin proposed theory of natural selection for the origin of species.
8. Sympatric speciation occurs by __________ isolation in a population.
Sympatric speciation occurs by reproductive isolation in a population.
9. Evolution of man occured in tropical forests of ____________ .
Evolution of man occured in tropical forests of Africa, China, India.
Question. Select the correct alternative :
1. Identify the pre-human ancestor
c. Neanderthal man
2. Erect posture played a significant role in the evolution of man as
a. Forelimbs are free to be used as hands.
b. Increase in complexity of brain led to high intelligence.
c. Changed food habits
d. Helped in speech development
Forelimbs are free to be used as hands.
3. The common ancestor of apes and hominids is thought to have lived :
a. In a forest and climbed trees.
b. On the ground in a forest.
c. On the ground in the savannah grasslands
d. On the ground in the mountains.
In a forest and climbed trees.
4. Which one of the following changes did not contribute to the transition from quadraped to biped?
a. Legs became longer than arms
b. The pelvis became shorter
c. Loss of tail
d. The sole of the feet became arched
Loss of tail
5. This is not a vestigial organ in man
a. External ear
b. Vermiform appendix
c. Third pair of molars
d. Second pair of molars
Second pair of molars
6. The characteristic that cast doubt on the Java man as an ancient human was
a. The age of the fossils
b. The structure of the thigh bone
c. The size of the skull cap
d. Its similarity to the Peking man
The age of the fossils
7. The organism studied for industrial melanism was a
c. Honey bee
8. The most apparent change during the evolutionary history of Homo sapiens is traced in :
a. Loss of body hair
b. Walking upright
c. Shortening of the jaws
d. Remarkable increase in brain size
9. The extinct representative of the present day living human is :
b. Neanderthal man
c. Java man
d. Homo habilis
10. According to fossils discovered up to present time, origin and evolution of humans started from
11. As primates evolved, their diet changed from :
a. Insects to mammals
b. Plants to mammals
c. Insects to plants
d. Plants to vertebrates
Insects to plants
12. Acquired characters are not passed on to offspring because they
a. Develop response to the environment
b. Do not develop due to change in the genes of gemetes
c. Are somatic variations
d. Develop due to change in functioning of body cells.
Do not develop due to change in the genes of gemetes
13. Evolutionary convergence is development of
a. Common set of characters in group of different ancestry
b. Dissimilar characters in closely related groups
c. Common set of characters in closely related groups
d. Random mating
Common set of characters in group of different ancestry
14. Which one of the following phenomena supports Darwin’s concept of Natural Selection in organic evolution?
a. Development of transgenic animals
b. Production of ‘Dolly’ the sheep by cloning
c. Prevalence of pesticide resistant insects
d. Development of organs from ‘stem cells’ for organ transplantation.
Prevalence of pesticide resistant insects
15. Evidence shows that ceremonial burial of dead body was first practised by :
b. Neanderthal man
c. Homo erectus
d. Homo habilis
16. Which of the following sequences was proposed by Darwin for organic evolution?
a. Overproduction, variation, constancy of population size, natural selection
b. Variations, constancy of population size, overproduction, natural selection
c. Overproduction, constancy of population size, variations, natural selection
d. Variations, natural selection, overproduction, constancy of population size
Overproduction, constancy of population size, variations, natural selection
17. Which of the following is not at ape?
18. The point which does not support Darwin’s theory is
a. Natural selection
b. Survival of the fittest
c. Use and disuse of certain structures
d. Struggle for existence
Use and disuse of certain structures
19. An important evidence in favour of organic evolution is the occurrence of
a. Homologous and analogous organs
b. Homologous and vestigial organs
c. Analogous and vestigial organs
d. Homologous organs only
Homologous and analogous organs
20. The chronological order of human evolution from early to the recent is :
a. Ramapithecus → Australopithecus → Homo habilis → Homo erectus
b. Ramapithecus → Homo habilis → Australopithecus → Homo erectus
c. Australopithecus → Homo erectus → Homo sapien → Homo habilis
d. Homo habilis → Homo sapiens → Homo erectus → Homo sapiens sapiens
Ramapithecus → Australopithecus → Homo habilis → Homo erectus
21. Which is NOT a hominid feature?
a. Upright posture
b. Bipedal locomotion
c. Construction and use of tools
d. Small brain and large teeth
Small brain and large teeth
22. This hominid used fire for cooking and had developed speech.
a. Homo erectus
b. Homo habilis
c. Homo sapiens
d. Homo sapiens sapiens
23. Which one of the following describes correctly the homologous structures?
a. Organs with anatomical similarities, but performing different functions
b. Organs with anatomical dissimilarities, but performing same functions
c. Organs that have no functions now, but had an important function in ancestor
d. Organs appearing only in embryonic stage and disappearing later in adult
Organs with anatomical similarities, but performing different functions
24. Germinal variations occur due to
a. Changes in DNA of germ cells
b. Union of gametes
c. Accumulation of small changes in the body
d. Body’s response to environment
Changes in DNA of germ cells
25. The first use of fire by hominids is associated with
a. Homo habilis
b. Homo erectus
c. Homo sapiens
Question. State whether the following sentences are true or false. If false, rewrite the correct form of the statements.
1. Variation occur due to evolution.
False : Evolution occur due to variation.
2. Wings of bat and wings of butterfly are homologous organs.
False : Wings of bat and wings of butterfly are analogous organs.
3. The cranial cavity of Cro-Magnon man was 1450cc.
False : The cranial cavity of Cro-Magnon man was 1450 – 1500cc.
4. Phenomenon of industrial melanism demonstrates induced mutation.
False : Phenomenon of industrial melanism demonstrates natural selection.
5. Acquired traits are non-inheritable traits.
6. The study of fossils is called palaeontology.
7. The Pleistocene climate is considered best for evolution of humans.
8. Australopithecus used fire for cooking.
False : Homo erectus used fire for cooking.
9. Humans have a short pelvis as compared to apes.
10. Common origin of humans and chimpanzee is best shown by binocular vision.
11. The genus Homo appeared about 2 million years ago.
False : The genus Homo appeared about 2.3 – 1.5 million years ago.
12. Birds and mammals have evolved from reptiles.
13. Man and apes have evolved from a common ancestor.
14. Wings of birds and hands of humans are homologous organs.
15. Evidence indicates that Australopithecus used crude tools.
False : Evidence indicates that Homo habilis used crude tools.
Question. Why are our ancestors supposed to shift from tree-dwelling mode of life to land life?
Ans. Our ancestors are supposed to shift from tree-dwelling mode of life to land life due to:
(a) Reduction in the number of trees due to dry climate and appearance of grasslands.
(b) Increased competition because of increase in ape’s population.
Question. What are vestigial organs? Name any three vestigial organs found in humans.
Ans. Vestigial organs are examples of non-functional organs in present day forms. Examples of vestigial organs found in humans are:
(a) Vermiform appendix is functional in herbivorous mammals where it is needed for the digestion of cellulose. Because of changed food habits of man, appendix is not functional and had gradually reduced.
(b) Third pair of molars found in ancestors are not needed in man and erupt late at the age of 16 years or later. These are called wisdom teeth.
(c) External ear or pinna served the purpose of gathering sound waves by mammals and ancestral man. But in modern civilised man, pinna is of no use. Hence, it is reduced and its auricular muscles are non-functional.
Question. Explain the term ‘species’. What is ‘speciation’? Mention the different types of speciation.
Ans. ‘Species’ is a group of populations of organisms that have similar appearance and genetic composition and can interbreed to produce fertile offspring, but they are reproductively isolated from all other species. The process of formation of new species from the populations of existing species is called ‘speciation’. Speciation is the origin of new species.
Speciation can occur in a number of ways. For example :
(a) Geographical speciation or Allopatric Speciation :
It occurs when a large and widely distributed population of a species gets divided by some geographical barrier into two or more subpopulations.
(b) Sympatric Speciation :
It occurs by sudden development of reproductive isolation in few members of the parental population living in the same geographic area.
Question. Give any four adaptations evolved during human evolution to live on land?
Ans. Four important adaptations evolved during human evolution to live on land are:
(a) Erect posture and Bipedalism : A well-developed pelvic girdle and erect vertebral column balancing the skull has freed the human forelimbs to perform various activities.
(b) Opposable thumb : The position of the thumb with reference to other fingers lends dexterity to humans allowing them to write, handle tools and perform delicate and precision tasks.
(c) Well-developed brain : Increase in the size and complexity of brain due to evolution of high intelligence and increase in the size of cranial capacity to 1450 – 1600 cm3.
(d) Stereoscopic vision : Humans have three dimensional vision because their eyes are forward facing. It enables them to gauge distance and depth accurately.
(e) Coloured vision : Humans are also able to distinguish between colours due to presence of colour-sensitive cones in the retina of the eye.
Question. Give the scientific name of the organism which is cited as the classical example of ‘Natural Selection’. Industrial melanism provides a good example of natural selection. Discuss.
Ans. The scientific name of the organism which is cited as the classical example of ‘Natural Selection’ is the peppered moth, Biston betularia.
Industrial Melanism :
(a) The peppered moth, Biston betularia with its light coloured wings dotted spots blended well with lichens growing on houses and tree trunks on which it rested. But there was also other variety that had darker wings.
(b) This dark variety was rare in 1850 in Manchester area because it was eaten up by birds being easily visible to them due to its black wings.
(c) The light-coloured moth was seen in larger number as it was well concealed while resting on houses and tree trunks. This situation was observed in this area before industrial revolution.
(d) But after industrial revolution in Manchester, the entire situation changed. The pollution in this area caused the death of lichens and darkening of the tree trunks with soot.
(e) Now, the dark variety was better hidden in this area, and was not easily picked by birds.
(f) Natural selection acted through the agency of the birds and light-coloured moth easily became the prey. So, the dark variety of moth survived better, left more offspring and almost nearly replaced the light form.
(g) This phenomenon has been called as Industrial Melanism.
Question. Distinguish between apes and humans on the following points : (Head, lower spine, length of arms and legs, pelvis, sole, thumb, brain)
Question. How would you justify that Australopithecus was a human ancestor?
Ans. (i) Australopithecus walked nearly straight.
(ii) The vertebral column had a distinct lumbar curve with broad pelvis.
(iii) The teeth were strikingly man-like because the dental arch was a smoothly rounded parabola, canines did not project beyond the level of other teeth, and a simian gap (a gap present in apes between incisors and canines on each side of jaw) was absent.
(iv) All these body features prove that Australopithecus was a human ancestor.
Question. List some structural limitations of the human body.
Ans. Some structural limitations of the human body:
(a) The erect posture and bipedal locomotion have made the human body more unstable as compared to quadrupedal animals.
(b) The loss of tail, which serves as a balancing organ in monkeys and other arboreal animals, has also made the human body unstable.
(c) Loss of hair on the skin has deprived humans of natural protection against cold conditions.
(d) Humans have a short, immovable ear pinna since the muscles which can move them are poorly developed. Therefore, humans cannot move their ears in the direction of sound waves.
(e) Humans have the least developed sense of smell, a feature that was traded for better sight.
(f) The human fingers and toes lack claws.
Question. Briefly discuss the ‘Theory of Natural Selection’ as given by Darwin.
Ans. The essential features of Darwin’s ‘Theory of Natural Selection’ are:
• Enormous Fertility and Overproduction :
To ensure continuity of race, organisms produce large number of offspring.
• Struggle for Existence :
The large number of individuals of all the species living together in the same area compete for same resources.
• Survival of Fittest :
Certain members are able to capture the resources better than others. They are more successful in the struggle for existence and produce more offspring.
• Variations and Heredity :
The new characters or new combinations of characters that arise due to heredity make living organisms different and better adapted to their environment.
• Natural Selection and Origin of Species :
Organisms with more advantageous traits are able to produce more offspring. These advantageous traits accumulate in the population generation after generation. Since in different environments, Natural selection favours accumulation of different variations, gene pools of sister populations of a species become markedly different. This leads to origin of new species.
Question. Name the six ancestral forms in their correct sequence through which modern man has evolved. Enlist the characteristics of each ancestor in detail.
Ans. The modern man (Homo sapiens sapiens) has evolved from :
Dryopithecus → Australopithecus → Homo habilis → Homo erectus → Homo sapiens neanderthalensis (Neanderthal man) → Homo sapiens fossilis (Cro-Magnon man)
Characteristics of Dryopithecus :
(a) The fossils of Dryopithecus were obtained from Africa, China, India and Europe.
(b) It lived in dense forests of tropical region about 25 million years ago.
(c) It was a tree dweller but had semi-erect posture and heel-like structure in hind legs.
(d) It had large canines and incisors for feeding on fruits and leaves.
Characteristics of Australopithecus (The Southern Ape) :
(a) Australopithecus is considered as the immediate forerunner of the genus Homo.
(b) It lived from 4 to 1.5 million years ago in the plains of Africa, Java and Ethiopia.
(c) It walked erect, lived on ground and probably used stones as weapons to hunt small animals.
(d) It was a hunter and cannibal.
(e) Australopithecus was an omnivore. Consequently, their molars were smaller than that of Dryopithecus but canines were larger than humans.
Characteristics of Homo habilis (The First Tool-maker Hominid) :
(a) Homo habilis lived in early Pleistocene epoch about 2.5 million years ago.
(b) It walked fully erect and had bipedal gait.
(c) It used forelimbs or hands to make stone tools.
(d) Homo habilis was hunter and omnivore.
(e) It lived a settled life in small groups.
(f) The size of its brain and cranial cavity was larger than that of Australopithecus (700 – 800 cc).
Characteristics of Homo erectus (Forerunner of Modern Humans) :
(a) Homo erectus lived about 1.6 million to 200,000 years ago in Africa, from where it spread out in Asia and Europe.
(b) It is described as ape-like man.
(c) It was upright with protruding jaws, thick eyebrow ridges but no chin.
(d) It was a hunter and food gatherer and was an omnivore.
(e) It used stone tools for hunting, chopping and scraping.
(f) It used fire for cooking and developed speech.
(g) Homo erectus had a cranial capacity of about 1000 cc much larger than that of Homo habilis.
(h) Homo erectus is called Ape-like man that walked straight.
Characteristics of Homo sapiens neanderthalensis (Neanderthal man–Thinkingman) :
(a) Homo sapiens neanderthalensis is described as ‘thinking man’ with much large brain of 1450 cc.
(b) It is very close to modern human with high forehead and distinct chin.
(c) The earliest Homo sapiens was Neanderthal man that lived in Germany.
Characteristics of Homo sapiens fossilis (Cro-Magnon man) :
(a) It is also Homo sapiens which existed during 30,000 years or more.
(b) It succeeded the Neanderthals.
(c) Its cranial capacity was about 1600 cc.
(d) It was cave-dweller and expert hunter.
(e) It spread to North America and Australia.
(f) It developed spear-heads and arrows and made ornaments from ivory.
(g) Homo erectus had a cranial capacity of about 1000 cc much larger than that of Homo habilis.
Question. Explain the mechanism of reproductive isolation responsible for speciation.
Ans. The reproductive isolation responsible for speciation can arise due to :
(a) Change in the number of chromosomes :
Multiplication of chromosome number in one plant prevents it from interbreeding with other members of the species. Such plants reproduce successfully by self pollination and increase their numbers, thus giving rise to a new species.
(b) Sudden development of some new mating procedure :
Some members of a population develop some new method of mating. They cannot mate with other members of parent population. This reproductively s ep ar a t e d group of organisms forms a new species.
(14) Enlist the various factors responsible for speciation.
Ans. A population becomes a species when it accumulates so many genetic differences that it becomes reproductively isolated from its sister populations. Various factors responsible for speciation :
(a) Geographic Isolation :
Due to appearance of some geographic barriers, the members of different populations of widely distributed species get isolated and are unable to interbreed or they interbreed rarely. It means the gene pool of species gets divided and isolated.
(b) Variations :
Different changes appear in the gene pool of different populations independently.
(c) Immigration :
It is migration of individuals from related populations. By interbreeding the immigrants introduce new genes in local population and make their gene pools different.
(d) Natural Selection :
It favours different genes or gene combinations in different populations, occupying different niches. Therefore, in the absence of interbreeding, gene pool of populations with different variations becomes diversified due to selection of
advantageous genes by natural selection.
(e) Genetic Drift :
Because of chance, survival of individuals of a particular genotype the gene pool of small populations becomes much diversified. This phenomenon is called sampling error or genetic drift.
(f) Reproductive Isolation :
Conservation of different variations in geographically isolated populations makes their gene pools so different that these populations are unable to interbreed and they develop into independent species.
Question. Look at the picture given below and answer the questions that follow
(a) Which theory does the given picture support?
(b) Who gave this theory
(c) Define the theory named in (a).
Ans. (a) The given picture supports Lamarck’s ‘Theory of Inheritance of Acquired Characters’.
(b) This theory was proposed by the French biologist, Jean Baptiste Lamarck.
(c) Whatever variations or changes an individual acquires in its lifetime due to internal vital force, effect of environment, new needs and because of use and disuse of organs, they are transmitted to the next generations. This process continues after several generations, these accumulated variations result in wide differences leading to the new species. This is called inheritance of acquired characters.
Question. What are ‘inherited traits’ and ‘acquired traits?
Ans. Inherited Traits :
Inherited traits are passed on from their parents to offspring. They are controlled by genes (specific functional segments of DNA). Inherited variations are changes in the DNA of germ cells or gametes. Hence they are also called as reproductive or germinal variations.
Acquired Traits :
Acquired traits appear in the individuals temporarily in response to the environment. These develop due to changes in the functioning of the body cells and not in the genes of gametes. Acquired traits are not passed on to offspring. Hence they form non heritable variations or somatic variations.
Question. What explanation was given by Lamarck for the following?
(a) Absence of legs in snakes.
(b) Evolution of long necks in giraffe
(c) Vestigial vermiform appendix in humans, whereas a well-developed appendix in herbivores like cows and buffaloes.
Ans. (a) Absence of legs in snakes : According to Lamarck, new habits involve use of certain organs to meet the new needs and disuse or lesser use of certain other organs. Continuous disuse of an organ or organs leads to gradual reduction in their size leading to their disappearance.
(b) Evolution of long neck in giraffe : According to Lamarck, giraffe evolved from some deer-like ancestors. They grazed on grass and had short neck and short forelimbs. As climate of the area became dry and the soft ground vegetation was replaced by a few tall trees, the leaves of these trees were the only source of food for them. So, they had to stretch their neck and forelegs to reach the tree leaves. This resulted in gradual elongation of neck and forelimbs. Whatever they acquired in one generation was transmitted to the next generation and with the result, the new race of giraffe with long neck and long forelimbs was developed.
(c) Vestigial vermiform appendix in humans, whereas a well-developed appendix
in herbivores like cows and buffaloes : Vermiform appendix is functional in herbivorous mammals where it is needed for the digestion of cellulose. Because of changed food habits of man, appendix is not functional and had gradually reduced.
Question. Answer the following questions :
(1) Mention the principles through which Lamarck explained his ideas.
Ans. The principles or four main postulates through which Lamarck explained his ideas are:
1. Internal Vital Force :
All living beings and their parts or organs tend to increase continually due to internal vital force
2. Effect of Environment and New Needs :
Environment influences all types of organisms. Any change in the environment brings about changes in organisms. New needs or desires produce changes in the structure or function of existing organs or new structures or changes in the habits of organisms.
3. Use and Disuse of Organs :
According to Lamarck, new habits involve use of certain organs to meet the new needs and disuse or lesser use of certain other organs. The continuous use of an organ or organs keeps them functional and makes them better developed while; continuous disuse of an organ or organs leads to gradual reduction in their size to their disappearance.
4. Inheritance of Acquired Characters :
Whatever variations or changes an individual acquires in its lifetime due to internal vital force, effect of environment, new needs and because of use or disuse of organs, they are transmitted to the next generations
Question. List the methods used for tracing human evolutionary relationships.
Ans. Following tools were used to trace evolutionary relationship between pre-human fossils and their ancestors :
(a) Excavation of fossils
(b) Determination of age of fossils by radioactive carbon – dating method.
(c) Tracing phylogenetic relationship using DNA sequencing (tracing similarities in the number and sequence of nucleotides in DNA.)
Question. The given picture shows vestigial organs in man. Answer the following questions.
(a) Name the vestigal organs labelled 1–4.
(b) What are vestigal organs?
(c) Name some vestigal organs in man other than those shown in this picture.
(d) Vestigal organ labelled 3 has significance in herbivores. Why?
Ans. (a) 1 – Chest hair
2 – Rudimentary non-functional mammary glands in males
3 – Vermiform appendix
4 – Tail vertebra or the coccyx
(b) Vestigial organs are example of non-functional organs in present-day forms. These organs were functional in the ancestors.
(c) In human beings some other vestigial organs are wisdom teeth, external ear or pinna, auricular muscles of external muscles, plica semilunaris and body hair.
(d) Vermiform appendix is functional in herbivorous mammals where it is needed for the digestion of cellulose. Because of changed food habits of man, appendix is not functional and had gradually reduced.
Question. The given picture shows an ape and a man. Answer the following questions :
(a) What basic difference is shown between the ape and the man?
(b) How does the difference stated above in (a) helped man to be a successful land dweller?
Ans. (a) Basic difference : Erect posture and Bipedalism
(b) Erect posture and bipedalism has freed the forelimbs to be used as hands for holding objects, gathering and transferring food and manipulation of tools.