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Heredity And Evolution Class 10th Science Tamilnadu Board Solution

Class 10th Science Tamilnadu Board Solution
Part-a
  1. Mendel observed 7 pairs of contrasting characters in Pisum sativum. Which one of the…
  2. Primitive man evolved in ___________A. Africa B. America C. Australia D. India…
  3. Which of the following is inheritable?A. an altered gene in sperm B. an altered gene in…
  4. The theory of Natural Selection was proposed by ___________ .A. Charles Darwin B. Hugo de…
  5. Somatic gene therapy causes ___________.A. changes in sperm B. changes in progeny C.…
  6. In a pea plant, the yellow colour of the seed dominates over the green colour. The genetic…
  7. Some people can roll their tongue and this is a genetically controlled auto-somal dominant…
  8. Hydra, a multi-cellular invertebrate of phylum Cnidaria (Coelenterata) can give rise to…
  9. The following are the events in the formation of the first cloned animal - the sheep…
  10. The following are statements about stem cells: a) There are unspecialised /…
  11. In persons suffering from insulin-dependent diabetes, _____ the cells of the pancreas…
  12. Identical twins are born as a result of fertilization between_______.A. two eggs and two…
  13. Identify the incorrect statement about identical twins.A. developed from a single zygote…
  14. The correct statement about Neanderthal man is:A. the first human-like hominid B. started…
  15. The inheritance of characteristics through generation is called “heredity”. In Mendel's…
Part-b
  1. Mendel has observed Tallness as a dominant character in the garden pea plant. Similarly,…
  2. The inheritable characters vary in different species and within the same species. Name the…
  3. Sexually reproducing organisms produce offspring with marked, significant and visible…
  4. Here are certain important hereditary jargons. Fill in the blanks by choosing a suitable…
  5. A change that affects the body cell is not inherited. However, a change in the gamete is…
  6. Sequentially arrange the different species of man from primitive to modern man.…
  7. Biotechnology, the modern science in biology, has helped in producing different types of…
  8. What do you mean by phenotype and genotype of an individual? Explain.…
  9. What are variations? Mention their types.
  10. Who proposed the theory of Natural Selection? Mention the two principles of this theory.…
  11. What are monoclonal antibodies? Mention its use.
  12. What is a clone? In what way is the cloning technique useful in the field of veterinary…
  13. In dogs, the barking trait is dominant over the silent trait. Using Punnet Square, work…
  14. In Dr. Ian Wilmut’s cloning experiment, did the new born 'Dolly' resemble the udder cell…
  15. The excessive use of pesticides has only resulted in the occurrence of more resistant…
  16. The first clinical gene therapy was given in 1990 to a four-year-old girl suffering from…
  17. Find the unmatched pairs:
  18. For the experimental research, Dr. Ian Wilmut used the nucleus of the udder cell from a…
  19. Match the following by identifying the pair: (medicines, fuel, microbes, metabolism,…
  20. Mention the dominant and recessive traits observed by Mendel in the garden pea plant with…
Part-c
  1. Human evolution has undergone a record of changes during the past 15 million years. i)…
  2. Describe in brief Mendel’s monohybrid cross.
  3. Find out who I am? i) I am an acid used as a preservative and I have a sour taste. ii) I…
  4. State whether true or false. Correct the statements that are false. i) Variations give the…
  5. Observe the flow-chart of a monohybrid cross in a clitoria plant and write the answers for…
Part-a
Question 1.

Mendel observed 7 pairs of contrasting characters in Pisum sativum. Which one of the following is not a part of that?
A. Tall and dwarf

B. Yellow and green seed colour

C. Terminal and axial flower

D. Smooth and rough stem


Answer:

Seven pair of contrasting characters of pea plant selected by Mendel—


i. Seed shape - Round / Wrinkled


ii. Seed colour - Yellow / Green


iii. Flower colour - Violet / WhitePod


iv. shape - Full / ConstrictedPod


v. colour - Green / YellowFlower


vi. position - Axillary / Terminal


vii. Stem height - Tall / Dwarf


Question 2.

Primitive man evolved in ___________
A. Africa

B. America

C. Australia

D. India


Answer:

Fossils of man- like primates found in Tanzania and Ethiopia (East Africa). They ate fruit and were 4 feet tall. They walked upright and hunted with stones.


Question 3.

Which of the following is inheritable?
A. an altered gene in sperm

B. an altered gene in liver cells

C. an altered gene in skin cells

D. an altered gene in udder cells


Answer:

An altered gene in sperm is inheritable because the genes are transferred by sperm and egg so if there was any alteration in sperm with the egg than that alteration will be inherited by the child. Liver cells, skin cells, and udder cells are somatic cells but sperm is a reproductive cell. So, variation or mutation or alteration in the reproductive cell only passes on.


Question 4.

The theory of Natural Selection was proposed by ___________ .
A. Charles Darwin

B. Hugo de Vries

C. Gregor Johann Mendel

D. Jean Baptise Lamarck


Answer:

Charles Darwin proposed the theory of natural selection in 1859. He defined natural selection as "the populations which are a better fit in an environment will be selected by nature and will survive more."


Question 5.

Somatic gene therapy causes ___________.
A. changes in sperm

B. changes in progeny

C. changes in body cell

D. changes in ovum


Answer:

Gene therapy is the method that allows correction of gene defect diagnosed in a child or embryo.


In somatic gene therapy, normal(therapeutic) genes are transferred into any body cell other than a stem cell, gametocyte, gamete or germ cells.


It basically focuses on genetic disorders like hemophilia, thalassemia etc.


Question 6.

In a pea plant, the yellow colour of the seed dominates over the green colour. The genetic makeup of the green colour of the seed can be shown as ___________:
A. GG

B. Gg

C. Yy

D. yy


Answer:

As we know that yellow colour of seed is dominant over green colour.


So the genotype of yellow seed colour will be YY/ Yy.


And the genotype of green seed colour will be homozygous recessive that is yy.


Question 7.

Some people can roll their tongue and this is a genetically controlled auto-somal dominant character. [Roller = RR / Rr and Non-roller = rr]

A child who can roll the tongue has one brother who is a non-roller and two sisters who are rollers. If both the parents are rollers, the genotypes of their parents would be ____.
A. RR x RR

B. Rr x Rr

C. RR x rr

D. rr x rr


Answer:

If the genotype of the parents is Rr x Rr


Then by using the punnet square, we can find the genotype of the children.


By using punnet square we will get RR, Rr, Rr, rr genotype. RR, Rr, and Rr are the genotypes of child and two sisters who can roll their tongues and rr is the genotype of brother who is non-roller.


Genotype of Roller = RR / Rr and


Genotype of Non-roller = rr


Question 8.

Hydra, a multi-cellular invertebrate of phylum Cnidaria (Coelenterata) can give rise to new offspring by various methods. Choose the method by which the offspring are produced with significant variations.
A. budding

B. regeneration

C. sexual reproduction

D. asexual reproduction


Answer:

Asexual reproduction, budding, and regeneration produces offspring with minor variations but organisms produce offspring with sexual reproduction show significant and visible variations. During sexual reproduction, the genetic information from each parent get mixed and tranfer to the offspring which leads to variety in offsprings.


Question 9.

The following are the events in the formation of the first cloned animal – the sheep Dolly.

a) Removal of haploid nucleus from the ovum.

b) Implantation of ovum with diploid nucleus into the surrogate mother.

c) Collection of udder cell from the sheep.

d) Injection of diploid nucleus of udder cell into the enucleated ovum.

e) Development of a young clone.

The correct sequential order of these events is __________ .
A. abcde

B. cabed

C. cadbe

D. edcba


Answer:

The sheep Dolly was the first cloned mammal from an adult somatic cell. Dolly was developed by Dr.Ian Wilmut and his colleagues in Roselind Institute in Scotland in July 1996. There was no gentic modification carried out on donor nucleus. The scientists used the nucleus of udder cell which contains, diploid number(2n) of chromosomes. She was created by the technique of somatic cell nuclear transfer.


Question 10.

The following are statements about stem cells:

a) There are unspecialised / undifferentiated cells.

b) They can be transformed into any type of body cell.

c) They can multiply rapidly to form a large number of similar types of cells.

d) They cannot transform into cardiac cells or nerve cells.

e) They are obtained from reproductive progeny only.

The correct statements are ______________:
A. a, b, c only

B. c, d, e only

C. a, c, e only

D. b, c, e only


Answer:

Stem cells are biological cells that have the potency to give rise to the tissue and organs. These cells have the tendency of multiplying into numerous numbers of the same type of cell by mitosis. In mammals two types of stem cells are present—


i. Embryonic stem cells


ii. Adult stem cells


Question 11.

In persons suffering from insulin-dependent diabetes, _____ the cells of the pancreas degenerate.
A. Alpha

B. Beta

C. Gamma

D. Delta


Answer:

Pancrease is a composite gland. It consist of two type of cells—


i. Alpha cell - secreate glucogon (increase sugar level in blood)


ii. Beta cell - secreate insulin (reduce blood sugar level)


If beta cell degenerates than there will be less secreation of insulin, leads to more glucose(sugar) in blood Which leads to diabetes mellitus.


Question 12.

Identical twins are born as a result of fertilization between_______.
A. two eggs and two sperms

B. two eggs and one sperm

C. one egg and one sperm

D. one egg and two sperms


Answer:

Identical twins are represented as monozygotic. Identical twins are of the same sex as they developed from the single zygote, which forms two embryos.


Question 13.

Identify the incorrect statement about identical twins.
A. developed from a single zygote

B. always of the same sex

C. look alike in many aspects

D. differ in their blood groups


Answer:

Identical twins are represented as monozygotic. Identical twins are of the same sex as they developed from the single zygote(contain male or female sex chromosomes), which form two embryos. Identical twins have the same DNA. They also have the same blood group.


Question 14.

The correct statement about Neanderthal man is:
A. the first human-like hominid

B. started agriculture

C. ate meat and walked erectly

D. buried the dead


Answer:

The neanderthal man is also known as Homo sapiens neanderthals. Their fossils found in east and central Asia. They used hides to protect the body and buried their dead. Their brain size is 1400cc.


Question 15.

The inheritance of characteristics through generation is called “heredity”. In Mendel's Pisumsativum plant, the genetic material responsible for heredity is __________.
A. DNA

B. RNA

C. Protein

D. Cytoplasm


Answer:

Heredity is the transfer of characters from one generation to next.


DNA is a thread like a chain of nucleotides that carry genetic information. It is always double-stranded and contains nitrogen bases(adenine, guanine, thymine, and cytosine). It is the genetic material of almost all living organisms.


Part-b
Question 1.

Mendel has observed Tallness as a dominant character in the garden pea plant.

Similarly, tongue rolling is a dominant character in man. In a group of 60 students,

45 can roll their tongue and 15 are non-rollers.

i) In the above context, calculate the percentage of dominant and recessive characters.


Answer:

Total number of students = 60


Students who can roll their tongue(dominant) = 45


Non- roller students(recessive) = 15


Percentage of Students who can roll their tongue(dominant)



Percentage of Non- roller students(recessive) 


Percentage of dominant and recessive character is 75:25


= 3:1



Question 2.

The inheritable characters vary in different species and within the same species. Name the variation in the following cases.

The eye colour among the human beings are varied as blue, black, brown, green, etc.

i) This is called as _______variation.

The dentition in the rabbit and the elephant are not the same.

ii) This is called as __________ variation.


Answer:

(i) Intraspecific variation


It is defined as the differences that occur within the species.


(ii) Intergeneric variation


It is defined as the differences that occur between two or more genera.



Question 3.

Sexually reproducing organisms produce offspring with marked, significant and visible variation. Asexually reproducing offspring show minor variations.

i) Do you agree with the above statements?

ii) Among the following organisms point out the asexually reproducing organism.

(Cockroach, Euglena, Earthworm and Bird)


Answer:

(i) Yes, i agree with the above statements


Asexual reproduction produces offspring with minor variations but organisms reproducing offspring through sexual reproduction show significant and visible variations. During sexual reproduction the genetic information from each parent gets mixed and transfer to the offspring which leads to variety in offspring. In sexual reproduction two parents are involved and both the parents have different genetic information (DNA).


(ii) Euglena


Euglena undergo asexual reproduction and reproduce by binary fission. Binary fission is the division of cells into two daughter cells.



Question 4.

Here are certain important hereditary jargons. Fill in the blanks by choosing a suitable one from the list given. (allele, variation, speciation, gene, allelomorphs)

i) __________ are the factors which form the physical basis of inheritance.

ii)__________ is the alternate forms of the same gene.

iii)__________ are the expressions of contrasting pair of alleles.


Answer:

i) Gene are the factors which form the physical basis of inheritance.


ii) Allele is the alternate forms of the same gene.


iii) Allelomorphs are the expressions of contrasting pair of alleles.



Question 5.

A change that affects the body cell is not inherited. However, a change in the gamete is inherited. The effects of radiation at Hiroshima have been affecting generations.

Analyze the above statements and give your interpretation.


Answer:

Radiation at Hiroshima has been affected generations because the radiation at Hiroshima had altered the genes of germ cells. And the alternation in the germ cells( gametes) is inheritable.



Question 6.

Sequentially arrange the different species of man from primitive to modern man.

(Neanderthal man, Homo habilis, Homo erectus, Homo sapiens)


Answer:

Sequentially arrange of the different species of man from primitive to modern man are as follow—


Homo habilis


Homo erectus


Neanderthal man


Homo sapiens


Homo habilis


They are the first human-like. Their brain capacity was 600-800 cc. They did not eat meat and their fossils found in Africa. Appeared about 2 million years ago.


Homo erectus


They are also known as Java man. They ate meat and their brain capacity was 900 cc. Appeared about 1.5 million years ago.


Neanderthal mam


Their brain capacity is 1400 cc. They used hides to protect their body and buried their dead. Appeared about 100,000 years ago.


Homo sapiens


They are the modern man. They started human civilization, agriculture and cave art. Appeared about 50,000 years ago.



Question 7.

Biotechnology, the modern science in biology, has helped in producing different types of products. One of the following groups does not have a product of biotechnology.

Pick out and give reasons.

i) enzymes, organic acids, steroids, vaccines

ii) vaccines, enzymes, antibiotics, inorganic acids

iii) antibiotics, hormones, steroids, vaccines

iv) steroids, enzymes, antibodies, vaccines


Answer:

In the 2 group (vaccines, enzymes, antibiotics, inorganic acids.) Inorganic acid is not the product of the biotechnology.


Reason


Inorganic acid are also known as mineral acid. The mineral acid is an acid derived from one or more inorganic compounds.



Question 8.

What do you mean by phenotype and genotype of an individual? Explain.


Answer:

Genotype - the genetic constitution of an organism.


Phenotype - the external morphological characteristics of an organism.



Question 9.

What are variations? Mention their types.


Answer:

Variation defined as the differences in the characteristics of the individual of a progeny from each other or from their parents.


Or


Difference between a member of the same population or a different population.


Types of variation are—


i. Somatic variation


ii. Germinal variation


i. Somatic variation


The variation in the somatic cells (Cells beside sex cells) which is acquired by the individual in their life and not passed in their progenies.


ii. Germinal variation


The variation in the germ cells (Sex cells) of an organism and it is inheritable. Germinal variation leads to evolution.



Question 10.

Who proposed the theory of Natural Selection? Mention the two principles of this theory.


Answer:

Charles Darwin proposed the theory of natural selection in 1859. He defined natural selection as "the populations which are a better fit in an environment will be selected by nature and will survive more."


Natural selection based on—


i. Population size


ii. Variation inherited


iii. Limited natural resources


The two principles of this theory are—


i. Survival of the fittest


ii. Struggle for existence



Question 11.

What are monoclonal antibodies? Mention its use.


Answer:

Monoclonal antibodies


These are the antibodies that are made up of identical immune cells which are clones of the unique parent cell. These are produced by hybridoma technology.


These antibodies have a monovalent affinity.


Uses—


i. It is used for the treatment of autoimmune diseases like rheumatoid arthritis, Crohn's disease etc.


ii. It is used in cancer treatment.



Question 12.

What is a clone? In what way is the cloning technique useful in the field of veterinary science?


Answer:

Clone


It is a group of individual of same species(morphologically and genetically similar)


Or


It is defined as the exact copies of the single genetical parent.


Clones are of two types—


i. Natural clone


ii. Induced clone


The cloning technique useful in the field of veterinary science as valuable animals can be cloned from desirable adult cells.



Question 13.

In dogs, the barking trait is dominant over the silent trait. Using Punnet Square, work out the possible puppies born to two barking parents with genotype (Rr).


Answer:


RR – Barking


Rr – Barking


rr – Silent




Question 14.

In Dr. Ian Wilmut’s cloning experiment, did the new born 'Dolly' resemble the udder cell donor Dorset white sheep or the surrogate mother sheep? Give reasons.


Answer:

The new born 'Dolly' resemble the udder cell donor Dorset white sheep.


Because the udder cell from the ovum has a diploid nucleus of the Dorset white sheep. The new born "Dolly" show all the characters of the Dorset white sheep.



Question 15.

The excessive use of pesticides has only resulted in the occurrence of more resistant varieties of pests rather than their complete eradication. How can you link this with Darwin’s theory of Natural Selection and Evolution?


Answer:

If we Continuously use pesticides against pests then With the passage of time, some pests develop resistance against the pesticides by bringing modification in their structures. The pests which become resistant survived and thus selected by nature. It is an example of natural selection which shows the process of evolution.



Question 16.

The first clinical gene therapy was given in 1990 to a four-year-old girl suffering from Adenosine Deaminase Deficiency (ADA). Could you suggest a possible cure for such a disorder with the knowledge of gene therapy and its types?


Answer:

Gene therapy means the correction of defect gene diagnosed in a child or embryo.


It is used to treat defects in somatic(body) or gametic(sperm/egg) cells.


M. Please and W. F. Andresco Attempted gene therapy on a 5-year-old girl who is suffering from adenosine deaminase deficiency.


ADA caused due to the deletion of adenosine deaminase gene.


It can be cured by bone marrow transplantation. But this method is not fully curative.


So we grow lymphocytes from patient's blood in a culture.


Functional ADA DNA was introduced in the lymphocytes with the help of retroviral vector.


Then these Lymphocytes were transferred into the patient's body.


Diseases can be cured by gene therapy are—


i. Cystic fibrosis


ii. Cancer


iii. Parkinson's diseases, etc.


Type of gene therapy are—


i. Somatic gene therapy


In Somatic gene therapy, the Defective gene is replaced by therapeutic genes in somatic cells. The change is not passed on to the next generation.


ii. Germ linegene therapy


In this, germ cells are modified or corrected by introducing functional genes into their genomes. The changes are passed to the next generation.



Question 17.

Find the unmatched pairs:



Answer:

The unmatched pair is—


Interferon — Antiproteins of bacteria


Reason


Interferons are Anti-Viral Proteins which is produced by Virus-infected cells



Question 18.

For the experimental research, Dr. Ian Wilmut used the nucleus of the udder cell from a six-year-old Finn Dorset white sheep and preserved the diploid nucleus (2n). He took an ovum from the ovary of another sheep. The haploid ovum was removed. The diploid nucleus of the udder cell was injected into the cytoplasm of the enucleated ovum. Then the diploid nucleus ovum was implanted into the uterus of the surrogate mother sheep. The diploid ovum developed into a young one, named “Dolly”.

i) Why did Wilmut select the udder cell?

ii) Define the terms haploid and diploid.


Answer:

(i) Wilmut selects the udder cell because the nucleus of udder cell contains a diploid number(2n) of chromosomes with all the genes.


(ii) Haploid


i. The cell/organism that has half the usual number of chromosomes or a single set of chromosomes. (n)


ii. Gamete cells are haploid in humans.


iii. Meiotic cell division results in haploid cells.


Diploid


i. The cell/organism that has double the number of chromosomes or two sets of chromosomes. (2n)


ii. Somatic cells are diploid.


iii. Mitotic cell division result in diploid cells.



Question 19.

Match the following by identifying the pair:

(medicines, fuel, microbes, metabolism, organic acids)

i) vaccine ii) natural gas iii) citric acid

iv) monoclonal antibodies v) vitamins

(special case: to no upload without explanation)


Answer:



Question 20.

Mention the dominant and recessive traits observed by Mendel in the garden pea plant with respect to the seed and flower.


Answer:

The dominant and recessive traits observed by Mendel in the garden pea plant with respect to the seed and flower—


i. Seed shape - Round / Wrinkled


ii. Seed colour - Yellow / Green


iii. Flower colour - Violet / White


iv. Flower position- Axillary / Terminal



Part-c
Question 1.

Human evolution has undergone a record of changes during the past 15 million years.

i) Name the different species of mankind in chronological order from primitive to modern man.

ii) When were the primitive caves developed?

iii) Narrate the life led by an early man-like hominids.


Answer:

Dryopithecus


They were more ape-like. They ate leaves and fruits and have a hairy body. Walked like gorillas and chimpanzees.


Appeared around 20-25 million years ago.


Ramapithecus


They have teeth like modern man. They were more man-like.


Appeared around 14-15 million years ago.


Australopithecus


Their fossils found in East Africa. They are four feet tall and walked upright. They ate fruit and their brain capacity was 400-600 cc.


Appeared around 3-5 million years ago.


Homo habilis


They are the first human-like. Their brain capacity was 600-800 cc. They did not eat meat and their fossils found in Africa. Appeared about 2 million years ago.


Homo erectus


They are also known as Java man. They ate meat and their brain capacity was 900 cc. Appeared about 1.5 million years ago.


Neanderthal mam


Their brain capacity is 1400 cc. They used hides to protect their body and buried their dead. Appeared about 100,000 years ago.


Homo sapiens


They are the modern man. They started human civilization, agriculture and cave art. Appeared about 75,000-10,000 years ago.


(ii) primitive caves developed around 18,000 years ago.


A variety of cave painting was done by Cro-Magnon man. Cro-Magnon man was the ancestor of the modern living man.


(iii) Hominids are classified in the genus Australopithecus and genus Homo habilis.


Life led by hominids—


i. They hunted with stone weapons.


ii. Fossils found in East Africa.


iii. They did not eat meat.


iv. They walked upright.



Question 2.

Describe in brief Mendel’s monohybrid cross.


Answer:

Mendel select garden pea plant(Pisum sativum) for his experiment.


Mendel took garden pea plant because of the following reason—


i. It is easy to pollinate pea flowers.


ii. Flowers are bisexual and self pollinating.


iii. It produces a large number of seeds in one generation.


iv. Pea plant has a short life cycle.


Mendel took homozygous tall pea plant and cross it with homozygous drawf pea plant. In F1 generation all the pea plants are tall.


He then self-pollinated F1 generation plants to generate F2 generation plants.


In F2 generation he found 75% of the plants are tall and 25% are drawn.


Observations


i. F1 progenies show one of the parent's trait and trait of other parents was not seen.


ii. F2 stage show both of the parent trait in proportion 3:1.


iii. The contrasting traits did not show any blending at F1 and F2 stage.



Question 3.

Find out who I am?

i) I am an acid used as a preservative and I have a sour taste.

ii) I am organic and present in citrus fruits and I give immunity.

iii) I am a cholesterol containing steroid obtained from bread mould. I am the steroid.

iv) I am an enzyme and I cut DNA at specific sites.

v) I am the paste enzyme that joins segments of DNA.


Answer:

(i) Vinegar


(ii) Citric acid


(iii) prednisolone (steriod drugs)


(iv) Restriction endonucleases


(v) DNA ligase



Question 4.

State whether true or false. Correct the statements that are false.

i) Variations give the organisms an individuality of their own.

ii) Charles Darwin postulated the use and disuse theory.

iii) To understand evolution, a branching diagram or a tree diagram is used to show the inferred evolution and the relationship among various biological species.

iv) Genetic engineering is the modification of the genetic information of living organisms by manipulation of DNA by adding, removing or repairing part of the DNA and changing the phenotype


Answer:

(i) The statement is True.


(ii) The statement is False.


Correction


Jean Baptist Lamarck give the theory of use and disuse of organ. Charles darwin give the darwinian theory. The main concept of darwinian theory is natural selection and branching descent.


(iii) The statement is True.


(iv) The statement is True.



Question 5.

Observe the flow-chart of a monohybrid cross in a clitoria plant and write the answers for A, B, C, D



Answer:





A = gametes for F1 generation that are B and b.


B = F1 generation go on selfing and form gametes for F2 generation that are B, B, b and b.


C = phenotypic ratio that is


blue flowered : white flowered = 3:1


D = genotypic ratio that is


BB : Bb : bb = 1:2:1