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Lakhmir Singh solutions Biology for Class 10 (2019 Exam) chapter 4 Heredity and Evolution

Chapters

Lakhmir Singh Solutions for Physics for Class 10 (2019 Exam)

Lakhmir Singh Biology Class 10 (2019 Exam)

Biology for Class 10 (2019 Exam)

Chapter 4 - Heredity and Evolution

Pages 191 - 196

Which of the processes, sexual reproduction or asexual reproduction, bring about maximum variations in the offsprings?

Q 1 | Page 191

Name one variation in humans connected with ears.

 
Q 2 | Page 191

What constitutes the link between one generation and the next?

 
Q 3 | Page 191

If a trait A exists in 10% of a population of an asexually reproducing species and a trait B exists in 60% of the same population, which trait is likely to have arisen earlier?

Q 4 | Page 191

Mendel said that the characteristics or traits of organisms are carried from one generation to the next by internal factors which occur in pairs. What is the modern name for these factors?

Q 5 | Page 191

Some plants occur in one of the two sizes : tall or dwarf. This characteristic is controlled by one pair of genes. Tallness is dominant to dwarfness. Choose suitable letters for this gene pair.

Q 6 | Page 191

What are the chromosomes XY and XX known as?

Q 7 | Page 191

Which of the two, sperm or ovum, decides the sex of the child?

Q 8 | Page 191

State whether the following statement is true or false :
The sex of an infant is not a case of inheritance of characteristics.

Q 9 | Page 191

A new born child has an XY pair of chromosmes. Will it be a baby boy or a baby girl?

Q 10 | Page 191

Which of the following combinations of sex chromosomes produce a male child : XX or XY?

Q 11 | Page 191

Name the first scientist who studied the inheritance of traits from one generation to the next.

Q 12 | Page 191

What type of plants were used by Mendel for conducting his experiments on inheritance?

Q 13 | Page 191

The gene for red hair is recessive to the gene for black hair. What will be the hair colour of a person if he inherits a gene for red hair from his mother and a gene for black hair from his father?

Q 14 | Page 191

What are the four blood groups in humans?

Q 15 | Page 191

Name one reptile in given case where higher incubation temperature leads to the development of :male progeny.

Q 16.1 | Page 191

Name one reptile in given case where higher incubation temperature leads to the development of  female progeny.

 
Q 16.2 | Page 191

Fill in the following blanks with suitable words :                  

Genes always work in ................ .

Q 17.1 | Page 191

Fill in the following blanks with suitable words 

 In pea plants, the gene for dwarfness is ..............whereas that for tallness is ............ .

Q 17.2 | Page 191

Fill in the following blanks with suitable words 

Most people have ............earlobes but some have ............earlobes.

Q 17.3 | Page 191

Fill in the following blanks with suitable words :

 A human gamete contains.............. chromosomes whereas a normal body cell has .......... chromosomes in it.

Q 17.4 | Page 191

Fill in the following blanks with suitable words :

 All races of man have...........blood groups.

Q 17.5 | Page 191

Fill in the following blanks with suitable words :

 The...............chromosomes for a ............are XX whereas that for a ..............are XY.

Q 17.6 | Page 191

Which of the following represent tall plants and which represent short plants (or dwarf plants)?
(a) Tt
(b) tt
(c) TT
Give reason for your choice (The symbols have their usual meaning).

Q 18 | Page 192

A man having blood group O marries a woman having blood group B and they have a daughter. What will be the blood group of the daughter?

 
Q 19 | Page 192

Name the scientist who gave the laws of inheritance.

Q 20.1 | Page 192

Name an animal in which individuals can change sex. What does this indicate?

 
Q 20.2 | Page 192

Explain with an example, how genes control the characteristics (or traits).

 
Q 21 | Page 192

State one advantage of variation to a species.

Q 22 | Page 192

Explain how, sex is determined in human babies.

Q 23 | Page 192

What do the following symbols used in the topic on heredity represent?
(a) TT
(b) tt
(c) XX
(d) XY

Q 24 | Page 192

 What will you get in the F1 and F2 generations in the following cross?
Pure tall pea plant × Pure dwarf pea plant

Q 25.1 | Page 192

It it an example of monohybrid cross or dihybrid cross?

 
Q 25.2 | Page 192

In the F2 generation of a cross, progeny having different traits are produced in the ratio 3 : 1. State whether it is a monohybrid cross or a dihybrid cross? Give one example of such a cross.

Q 26 | Page 192

   What is the genotype of dwarf plants which always produced dwarf offspring?

Q 27.1 | Page 192

What is the genotype of tall plants which always produced tall offspring

Q 27.2 | Page 192

What is the genotype of (i) dwarf plants, and (ii) tall plants, whose parental cross always produces tall offspring?

Q 27.3 | Page 192

If a normal human cell has 46 chromosomes, how many chromosomes will be there in a human (i) sperm cell, and (ii) zygote?

Q 28.1 | Page 192

What sizes of plants are produced if both parents have genes Tt?

 
Q 28.2 | Page 192

In a human, how many chromosmes are present in a brain cell?

Q 29.1 | Page 192

In a human, how many chromosmes are present in a sperm in the testes?

Q 29.2 | Page 192

In a human, how many chromosmes are present in an egg which has just been produced by the ovary?

Q 29.3 | Page 192

In a human, how many chromosmes are present in a skin cell?

Q 29.4 | Page 192

In a human, how many chromosmes are present in a fertilised egg?

 
Q 29.5 | Page 192

Gregor Mendel's first law of genetics states "Of a pair of contrasted characters, only one can be represented in a gamete by its internal 'factor Give the modern name for this 'factor'.
 

Q 30.1 | Page 192

Gregor Mendel's first law of genetics states "Of a pair of contrasted characters, only one can be represented in a gamete by its internal 'factor' State where these factors are found in gametes.

 
Q 30.2 | Page 192

Does genetic combination of mother play a significant role in determining the sex of a new born baby?

 
Q 31 | Page 192

Give the contrasting traits of the following characters in pea plant and mention which is dominant and which is recessive:  

Yellow seed

Q 32.1 | Page 192

Give the contrasting traits of the following characters in pea plant and mention which is dominant and which is recessive :

 Round seed

 
Q 32.2 | Page 192

What are the units of heredity.

Q 33.1 | Page 192

What is heredity?

Q 33.1 | Page 192

State Mendel's first law of inheritance.

Q 33.2 | Page 192

 Why did Mendel choose pea plants for conducting his experiments on inheritance?

Q 34.1 | Page 193

State Mendel's second law of inheritance.

Q 34.2 | Page 193

What do you understand by the term 'variation'?

Q 35.1 | Page 193

Name two human traits which show variation.

Q 35.2 | Page 193

How does the creation of variation in a species ensure its survival

Q 35.3 | Page 193

What are genes? Where are they located in our body?

Q 36.1 | Page 193

What is meant by dominant genes and recessive genes? Give one example of each.

Q 36.2 | Page 193

Explain how, characteristics (or traits) are inherited through genes.

Q 36.3 | Page 193

How do Mendel's experiments show that traits may be dominant or recessive?

Q 37.1 | Page 193

How do Mendel's experiments show that traits are inherited independently?

Q 37.2 | Page 193

When two parents are crossed, the offspring are referred to as :
recessives
 test cross
 F1 generation
 F2 generation

Q 38 | Page 193

 A cross between two individuals results in a ratio of 9 : 3 : 3 : 1 for four possible phenotypes of progeny. This is an example of a :

dihybrid cross
monohybrid cross
test cross
(d) none of these

Q 39 | Page 193

For his experiments on heredity, Mendel used :
 papaya plants
 potato plants
 pea plants
 pear plants

 
Q 40 | Page 193

The human animal which has an XY pair of chromosomes is called :
(a) male
(b) hybrid
(c) female
(d) doomed

Q 41 | Page 193

The science of heredity is known as :
(a) biology
(b) embryology
(c) genetics
(d) biochemistry

Q 42 | Page 193

A gene is a :
(a) hybrid
(b) heritable trait
(c) pure breed
(d) part of a chromosome that transmits a trait

Q 43 | Page 193

A normal cell of human body contains 23 pairs of chromosomes. The number of chromosomes  in a sex cell (sperm or ovum) of a human being is most likely to be :
(a) 46
(b) 23
(c) 21
(d) 42

 
Q 44 | Page 193

In order to ensure that he had pure-breeding plants for his experiments, Mendel :
(a) cross-fertilised each variety with each other
(b) let each variety self fertilise for several generations
(c) removed the female parts of the plants
(d) removed the male parts of the plants.

 
Q 45 | Page 193

In the human blood grouping, the four basic blood types are type A, type B, type AB, and type O. The blood proteins A and B are :
(a) simple dominant and recessive traits
(b) incomplete dominant traits
(c) codominant traits
(d) sex-linked traits

Q 46 | Page 193

 A plant with two 'small' genes breeds with a plant with two 'tall' genes to produce :

(a) small plants and tall plants in the ratio 1 : 3
(b) all small plants
(c) all tall plants
(d) tall plants and small plants in the ratio 3 : 1

 
Q 47 | Page 193

A pregnant woman has an equal chance of her baby being blood group A or blood group AB. Which one of the following shows the possible genotypes of the woman and the father of her child?
(a) IA IA and IB IO
(b) IA IB and IB IO
(c) IA IO and IB IO
(d) IA IB and IA IO

Q 48 | Page 193

The palisade cells of a species of plant contain 28 chromosomes. How many chromosomes will there be in each gamete produced by the plant?
(a) 56
(b) 28
(c) 14
(d) 4

Q 49 | Page 193

Which of the following may be used to obtain an F2 generation?
(a) allowing flowers on a parent plant to be self-pollinated
(b) allowing flowers on an F1 plant to be self-pollinated
(c) cross-pollinating an F1 plant with a parent plant
(d) cross-pollinating two parent plants

Q 50 | Page 193

The following results were obtained by a scientist who crossed the F1 generation of pure-breeding parents for round and wrinkled seeds.

Dominant trait Recessive trait No. of F2 offspring
Round seeds Wrinkled seeds 7524

From these results, it can be concluded that the actual number of round seeds he obtained was:
(a) 1881
(b) 22572
(c) 2508
(d) 5643

Q 51 | Page 194

The visible characteristic in an organism is known as :
(a) prototype
(b) stereotype
(c) phenotype
(d) genotype

Q 52 | Page 194

The exchange of genetic material takes place in :
(a) vegetative reproduction
(b) asexual reproduction
(c) sexual reproduction
(d) budding

Q 53 | Page 194

A cross between a tall plant (TT) and short plant (tt) resulted in progeny that were all tall plants because :
(a) tallness is the dominant trait
(b) shortness is the dominant trait
(c) tallness is the recessive trait
(d) height of plant is not governed by gene T or t

Q 54 | Page 194

The number of pair(s) of sex chromosomes in the zygote of humans is :
(a) one
(b) two
(c) three
(d) four

Q 55 | Page 194

In peas, a pure tall plant (TT) is crossed with a pure short plant (tt). The ratio of pure tall plants to pure short plants in F2 generation will be :
(a) 1 : 3
(b) 3 : 1
(c) 1 : 1
(d) 2 : 1

Q 56 | Page 194

The two versions of a trait (character) which are brought in by the male and female gametes are situated on :
(a) copies of the same chromosome
(b) sex chromosomes
(c) two different chromosomes
(d) any chromosomes

Q 57 | Page 194

Select the statements that describe characteristics of genes :
(i) genes are specific sequence of bases in a DNA molecule
(ii) a gene does not code for proteins
(iii) in individuals of a given species, a specific gene is located on a particular chromosome
(iv) each chromosome has only one gene

(a) (i) and (ii)
(b) (i) and (iii)
(c) (i) and (iv)
(d) (ii) and (iv)

Q 58 | Page 194

Select the group which shares the maximum number of common characters :
(a) two individuals of a species
(b) two species of a genus
(c) two genera of a family
(d) two genera of two families

Q 59 | Page 194

A trait in an organism is influenced by :
(a) paternal DNA only
(b) maternal DNA only
(c) both maternal and paternal DNA
(d) neither by paternal nor by maternal DNA.

Q 60 | Page 194

In human males all the chromosomes are paired perfectly except one. This/these unpaired chromosomes is/are :
(i) large chromosome
(ii) small chromosome
(iii) Y chromosome
(iv) X chromosome

Q 61 | Page 194

The sex of a child is determined by which of the following?
(a) the length of the mother's pregnancy
(b) the length of time between ovulation and copulation
(c) the presence of and X chromosome in an ovum
(d) the presence of a Y chromosome in a sperm

 
Q 62 | Page 194

A zygote which has inherited an X chromosome from the father will develop into :
(a) baby boy
(b) baby girl
(c) adult
(d) either boy or girl

Q 63 | Page 194

Which of the following statement is incorrect?
(a) for every hormone there is a gene
(b) for every protein there is a gene
(c) for production of every enzyme there is a gene
(d) for every type of fat there is a gene

Q 64 | Page 194

If the ratio of each phenotype of the seeds of pea plants in the F2 generation is 9 : 3 : 3 : 1, it is known as :
(a) tetrahybrid ratio
(b) monohybrid ratio
(c) dihybrid ratio
(d) trihybrid ratio

Q 65 | Page 195

In humans, if gene B gives brown eyes and gene b gives blue eyes. What will be the colour of eyes of the persons having the following combination of genes?
(a) Bb
(b) bb
(c) BB

Q 66 | Page 195

Pure-bred pea plants A are crossed with pure-bred pea plants B. It is found that the plants which look like A do not appear in F1 generation but re-emerge in F2 generation. Which of the plants A and B are : (i) tall, and (ii) dwarf? Give reason for your answer.

 
Q 67 | Page 195

Pure-bred tall pea plants are first crossed with pure-bred dwarf pea plants. The pea plants obtained in F1generation are then cross-bred to produce F2 generation of pea plants.
(a) What do the plants of F1 generation look like?
(b) What is the ratio of tall plants to dwarf plants in F2 generation?
(c) Which type of plants were missing in F1 generation but reappeared in F2 generation?

 
Q 68 | Page 195

A plant has two varieties, one with red petals and the other with white petals. When these two varieties are cross-pollinated, all the offsprings have red petals?
(a) Which gene is dominant?
(b) Choose suitable letters to represent the two genes.

Q 69 | Page 195

A red-haired woman marries a brown-haired man, and all the children are brown haired. Explain this genetically.

 
Q 70 | Page 195

A black mouse mates with a brown mouse, and all the offsprings are black.
(a) Why are no brown offsprings produced?
(b) If two of the black offsprings mate with each other what kind of offspring would you           expect  and in what proportions? Give reason for your answer.

 
Q 71 | Page 195

(a) E is the gene for brown eye colour and an is the gene for blue eye colour. which gene is (1)  recessive, and (2) dominant?

Q 72.1 | Page 195

(b) Both father and mother have the genes Ee in their cells. What colour are their eyes?

Q 72.2 | Page 195

(c) Which combination of genes in the zygote will produce children with blue eyes?

Q 72.3 | Page 195

(d) Which combination of genes in the zygote will produce children with brown eyes?

 
Q 72.4 | Page 195

What are the possible blood groups likely to be inherited by children born to a group A mother and a group B father? Explain your reasoning.

 
Q 73 | Page 195

A couple with a newborn baby is troubled that the child does not resemble either of them. Suspecting that a mixup occurred at the hospital, they check the blood type of the infant. It is type O. Because the father is type A and the mother type B, they conclude that a mixup has definitely occurred. Are they correct? Give reason for your answer.

Q 74 | Page 195

A man with blood group A marries a woman with blood group O and their daughter has blood group O. Is this information enough to tell you which of the traits-blood group A or O - is dominant? Why or why not?

 
Q 75 | Page 195

A Mendelian experiment consisted of breeding tall pea plants bearing violet flowers with short pea plants bearing white flowers. The progeny all bore violet flowers, but almost half of them were short. This suggests that the genetic make-up of the tall parent can be depicted as
(a) TTWW
(b) TTww
(c) TtWW
(d) TtWw

Q 76 | Page 195

A person first crossed pure-bred pea plants having round-yellow seeds with pure-bred pea plants having wrinkled-green seeds and found that only A-B type of seeds were produced in the F1 generation. When F1generation pea plants having A-B type of seeds were cross-bred by self-pollination, then in addition to the original round-yellow and wrinkled-green seeds, two new varieties A-D and C-B type of seeds were also obtained.
(a) What are A-B type of seeds?
(b) State whether A and B are dominant traits or recessive traits.
(c) What are A-D type of seeds?
(d) What are C-B type of seeds?
(c) Out of A-B and A-D types of seeds, which one will be produced in (i) minimum numbers, and (ii) maximum numbers, in the F2 generation?

Q 77 | Page 195

The person A has only B chromosomes in all its gametes. On the other hand, another person C has chromosome D in half of gametes and chromosome E in the other half of gametes. When chromosomes B and D combine during fertilisation, a female zygote results. On the other hand, combination of B and E chromosomes produces a male zygote.
(a) What are chromosomes (i) B (ii) D, and (iii) E?
(b) Out of B, D and E, which two chromosomes are of the same type?
(c) Which chromosome is smaller in size?
(d) What is the general name of chromosomes such as B and E?
(e) Out of the two persons A and C, which one is (i) male, and (ii) female?

Q 78 | Page 196

Mendel first crossed pure-bred pea plants having round-yellow seeds with pure-bred pea plants having wrinkled-green seeds and found that only round-yellow seeds were produced in the F1 generation. When F1generation pea plants having round-yellow seeds were cross-bred by self pollination, then peas having round-yellow seeds, round green seeds, wrinkled-yellow seeds and wrinkled-green seeds were produced. Mendel collected a total of 2160 seeds.
(a) What will be the number of (i) round green seeds (ii) wrinkled green seeds (iii) round yellow seeds, and (iv) wrinkled-yellow seeds?
(b) Which 'ratio' as established by Mendel have you made use of in answering the part (a) above?

Q 79 | Page 196

Pure-bred round-yellow pea seeds have genotype RRYY and the pure-bred wrinkled-green pea seeds have genotype rryy. Keeping this in mind, write the phenotypes of the following genotypes of hybrid pea seeds :
(a) Rryy
(b) rrYy
(c) rrYY
(d) RrYy
(e) RRyy

Q 80 | Page 196

Pages 208 - 212

What name is given to the sequence of gradual changes over millions of years in which new species are produced?

 
Q 1 | Page 208

Name the scientist who gave the theory of evolution.

 
Q 2 | Page 208

State whether the following statement is true or false :
Human beings have evolved from chimpanzees.

Q 3 | Page 208

State one characteristic which shows that the birds are very closely related to dinosaurs.

 
Q 4 | Page 208

Name an animal having rudimentary eyes.

Q 5 | Page 208

Name the ancestor of the following :
Broccoli, Kohlrabi, Kale

Q 6 | Page 208

Where did life originate on the earth?

Q 7 | Page 208

Write the names of at least three inorganic molecules which helped in the origin of life on the earth.

Q 8 | Page 209

Name the famous book written by Charles Robert Darwin.

Q 9 | Page 209

The forelimbs of a frog, a bird and a man show the same basic design (or basic structure) of bones. What name is given to such organs?

 
Q 10 | Page 209

Name two organisms which are now extinct and studied from their fossils.

 
Q 11 | Page 209

Out of the wing of a bird, wing of an insect and the wing of a bat :
(a) which two are homologous organs?
(b) which two are analogous organs?

Q 12 | Page 209

Why are human beings who look so different from each other in terms of size, colour and looks said to belong to same species?

Q 13 | Page 209

 Name five varieties of vegetables which have been produced from 'wild cabbage' by the process of artificial selection.

 
Q 14 | Page 209

Choose the one term from the following which includes the other three :
broccoli, wild cabbage, cauliflower, cabbage

Q 15 | Page 209

Fill in the following blanks with suitable words :

The human forelimb and bat's forelimb are an example of .......... organs whereas an insect's wing and a bat's wing are an example of ........... organs.

Q 16.1 | Page 209

Fill in the following blanks with suitable words :

 The evolution of eye is an example of evolution by ............

Q 16.2 | Page 209

Fill in the following blanks with suitable words :

The scientific name of all human beings is ..............

Q 16.3 | Page 209

Fill in the following blanks with suitable words:

 Broccoli has evolved from .............. by the process of artificial selection.

Q 16.4 | Page 209

Fill in the following blanks with suitable words :

The theory of natural selection for evolution was proposed by ..............

Q 16.5 | Page 209

Match the terms given in column I with those given in column II :

                Column I Column II
(1) Fossil (a) A famous evolutionist
(2)  A theory of evolution (b) Survival of the fittest
(3)  Probable ancestor of birds (c) Petrified remains of prehistoric life
(4)  Charles Darwin (d) Father of genetics
(5) Gregor Mendel (e) Archaeopteryx

 

Q 17 | Page 209

What is meant by acquired and inherited traits? Explain with one example each.

Q 18 | Page 209

Why are traits acquired during the life-time of an individual not inherited?

Q 19 | Page 209

Can the wing of a butterfly and the wing of a bat be considered homologous organs? Why or why not?

Q 20 | Page 209

Name two animals having homologous organs and two having analogous organs. Name these organs.

 
Q 21 | Page 209

What are fossils? Giving one example, explain how fossils provide evidence for evolution.

Q 22 | Page 209

Give an example of characteristics being used to determine how close two species are in evolutionary terms.

 
Q 23 | Page 209

 In what way are homologous organs evidence for evolution?

 
 
Q 24 | Page 209

Why are the small numbers of surviving tigers a cause of worry from the point of view of genetics?

Q 25 | Page 209

Will geographical isolation be a major factor in the speciation of an organism that reproduces asexually? Why or why not?

Q 26 | Page 209

Name the various tools of tracing evolutionary relationships which have been used for studying human evolution.

Q 27 | Page 209

Out of bacteria, spider, fish and chimpanzee, which organism has a better body design in evolutionary terms? Give reason for your answer.

Q 28 | Page 209

With the help of an example, explain how variation leads to evolution.

Q 29 | Page 209

What is meant by a species? 

Q 30.1 | Page 209

Give two examples of plant species and two of animals.

Q 30.1 | Page 209

 State the various factors which could lead to the formation of new species.

Q 30.2 | Page 209

What evidence do we have for the origin of life from inanimate matter (lifeless matter)

 
Q 31 | Page 209

Does geographical isolation of individuals of a species lead to the formation of a new species? Provide a suitable explanation for your answer.

Q 32 | Page 209

Bacteria have a simpler body plan when compared with human beings. Does it mean that human beings are more evolved than bacteria? Explain your answer.

Q 33 | Page 210

Name the scientist who gave the theory of origin of life on earth. What is this theory?

Q 34.1 | Page 210

How are those species which are now 'extinct' studied?

 
Q 34.2 | Page 210

What do you understand by the term 'evolution'?

Q 35.1 | Page 210

State Darwin's theory of evolution.

Q 35.1 | Page 210

Explain the terms 'analogous organs' and 'homologous organs' with examples.

Q 36.1 | Page 210

In what way are analogous organs evidence for evolution?

Q 36.2 | Page 210

Define 'speciation'. Explain how speciation occurs.

Q 37.1 | Page 210

"Only variations that confer an advantage to an individual organism will survive in a population". Do you agree with this statement? Give reason for your answer.

Q 37.2 | Page 210

 Will geographical isolation be a major factor in the speciation of a self-pollinating plant species? Give reason for your answer.

Q 37.2 | Page 210

Define 'natural selection'.

Q 38.1 | Page 210

 In evolutionary terms, we have more in common with
(a) a Chinese school-boy.
(b) a chimpanzee.
(c) a spider.
(d) a bacterium.

Q 39 | Page 210

The human species has genetic roots in :
(a) America
(b) Africa
(c) Australia
(d) Antarctica

Q 40 | Page 210

Which of the following gas was not present in early earth atmosphere?
(a) Ammonia
(b) Oxygen
(c) Hydrogen sulphide
(d) Methane

 
Q 41 | Page 210

A gradual change, over a long period, in a form of life is known as :
(a) erosion
(b) evolution
(c) revolution
(d) evaluation

Q 42 | Page 210

Scientists believe that all life originated in :
(a) the sea
(b) the soil
(c) the ground
(d) the air

Q 43 | Page 210

According to scientists, aves have evolved from :
(a) mammals
(b) amphibians
(c) reptiles
(d) arthropods

Q 44 | Page 210

The theory of evolution of species by natural selection was given by :
(a) Mendel
(b) Darwin
(c) Dalton
(d) Lamarck

Q 45 | Page 210

The term 'father of genetics' is used for the scientist :
(a) Morgan
(b) Mendel
(c) Darwin
(d) Marie Curie

Q 46 | Page 210

One of the following traits cannot be inherited. This one is :
(a) colour of eyes
(b) colour of skin
(c) size of body
(d) nature of hair

Q 47 | Page 210

Only one of the following characteristic of the parents can be inherited by their children. This one is :
(a) deep scar on chin
(b) snub nose
(c) technique of swimming
(d) cut nose

Q 48 | Page 210

The organs which perform different functions but have the same basic structure are known as :
(a) homologous organs
(b) analogous organs
(c) homolytic organs
(d) analytic organs

Q 49 | Page 210

The organs which perform similar functions but have different basic structure are called :
(a) asymmetric organs
(b) analogous organs
(c) homologous organs
(d) homophonic organs

Q 50 | Page 210

Wing of an insect and forelimb of a bird are :
(a) analogous organs
(b) analeptic organs
(c) homologous
(d) homophobic organs

Q 51 | Page 210

If the fossil of an organism is found in the deeper layers of earth, then we can predict that :
(a) the extinction of organism has occurred recently
(b) the extinction of organism has occurred thousands of years ago
(c) the fossil position in the layers of earth is not related to its time of extinction
(d) time of extinction cannot be determined.

Q 52 | Page 210

Which of the following statement is incorrect with respect to variations?
(a) all variations in a species have equal chance of survival
(b) change in genetic composition results in variations
(c) selection of variations by environmental factors forms the basis of evolutionary process
(d) variations are the minimum in asexual reproduction

Q 53 | Page 210

One of the following traits of the parents cannot be passed on to their future generations. This trait is :
(a) cleft chin
(b) pointed chin
(c) scarred chin
(d) broad chin

Q 54 | Page 211

Some dinosaurs had feathers although they could not fly but birds have feathers that help them to fly. In the context of evolution, this means that :
(a) reptiles have evolved from birds
(b) there is no evolutionary connection between reptiles and birds
(c) feathers are homologous structures in both the organisms
(d) birds have evolved from reptiles.

 
Q 55 | Page 211

Select the incorrect statement from the following :
(a) frequency of certain genes in a population changes over several generations resulting in        evolution
(b) reduction in the weight of an organism due to starvation is genetically controlled
(c) low weight parents can have heavy weight progeny
(d) traits which are not inherited over generations do not cause evolution.

Q 56 | Page 211

New species may be formed if :
(i) DNA undergoes significant changes in germ cells
(ii) chromosome number changes in the gamete
(iii) there is no change in the genetic material
(iv) mating does not take place

(a) (i) and (ii)
(b) (i) and (iii)
(c) (ii), (iii) and (iv)
(d) (i), (ii) and (iii)

Q 57 | Page 211

According to the evolutionary theory, formation of a new species is generally due to :
(a) sudden creation by nature
(b) accumulation of variations over several generations
(c) clones formed during asexual reproduction
(d) movement of individuals from one habitat to another.

Q 58 | Page 211

The presence of which of the following types of organs in two animals indicates that they are not derived from a common ancestor?
(a) homologous organs
(b) excretory organs
(c) analogous organs
(d) reproductive organs

Q 59 | Page 211

The presence of which of the following types of organs in two organisms indicates that they are derived from the same ancestor?
(a) analogous organs
(b) respiratory organs
(c) digestive organs
(d) homologous organs

Q 60 | Page 211

One of the following has not been produced from wild cabbage by the process of artificial selection. This one is :
(a) kohlrabi
(b) cabbage
(c) spinach
(d) kale

Q 61 | Page 211

The fossil trilobite was originally :
(a) an arthropod
(b) an invertebrate
(c) a reptile
(d) an ave

Q 62 | Page 211

One pair of organs in the following animals are not homologous. This is :
(a) forelimbs in humans and lizard
(b) forelimbs in lizard and frog
(c) wings in butterfly and bat
(d) wings in bat and bird

Q 63 | Page 211

 The wings of a housefly and the wings of a sparrow are an example of :
(a) analogous organs
(b) vestigial organs
(c) respiratory organs
(d) homologous organs

Q 64 | Page 211

Some of the important fossils which have been studied are those of organisms X, Y and Z. X were marine arthropods which were common between 400 to 600 million years ago. Y were the invertebrate animals (molluscs) with a flat, coiled, spiral shell which lived in the sea about 180 million years ago. Z are the extinct carnivorous or herbivorous reptiles which appeared on the earth about 250 million years ago and became extinct about 65 million years ago. What are X, Y and Z?

Q 65 | Page 211

The farmers have been cultivating a food plant X for over two thousand years and have produced as many as five entirely different looking vegetables A, B, C, D and E from it.
(a) What could the plant X be?
(b) What are A, B, C, D and E?
(c) What is the process of evolution involved in this example known as?

Q 66 | Page 212

There are five animals A, B, C, D and E. The animal A uses its modified forelimbs for flying. The animal B uses its forelimbs for running whereas the animal C uses its forelimbs for grasping. The animal D can live on land as well as in water and uses its forelimbs to prop up the front end of its body when at rest. The animal E which respires by using spiracles and tracheae uses wings for flying but its wings are analogous to the modified forelimbs of animal A.
(a) What could the animals A, B, C, D and E be?
(b) Why are the forelimbs of animals A, B, C, D called homologous organs?
(c) What does the existence of homologous organs in animals A, B, C and D tell us about their ancestors ?
(d) Why are the modified forelimbs of animal A and the wings of animal E called analogous organs?
(e) State whether animals A and E have a common ancestor or not.

Q 67 | Page 212

X, Y, and Z are three animals. The animal X can fly but animal Y can only run on ground or walls. The forelimbs of animals X and Y have the same basic design but they are used for different purposes such as flying and running respectively. The animal Z became extinct an long time ago. The study of fossils of Z tells us that it had some features like those of X and some like those of Y. In fact, Z is said to form a connecting link in the evolutionary chain of X and Y.
(a) What could the animals X, Y and Z be?
(b) What name is given to the forelimbs like those of X and Y which have the same basic design but different functions?
(c) Name one feature in which Z resembled X.
(d) Name one feature in which Z resembled Y.
(e) Which is the correct evolutionary chain involving X, Y and Z : X → Z → Y or Y → Z → X?

Q 68 | Page 212

A population of red beetles lives in green bushes in a garden. Once during the process of breeding, a green beetle is produced.
(a) State whether the change in colour of beetle is a process of evolution or not.
(b) Can the new colour of green beetle be passed on to its next generations?
(c) What will be the advantage (if any) of the green colour to the beetle?
(d) State whether the production of green colour involved a change in genetic material or not.

Q 69 | Page 212

The organs P and Q of two animals have different structures but similar functions. On the other hand, the two organs R and S of two other animals have the same basic structure but different functions.
(a) What are the organs like P and Q known as?
(b) Name the organs like P and Q. Also name the animals which have such organs.
(c) What are the organs like R and S called?
(d) Name the organs like R and S. Also name the animals which have such organs.

Q 70 | Page 212

Lakhmir Singh Biology Class 10 (2019 Exam)

Biology for Class 10 (2019 Exam)
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