NCERT Solutions For Class 10th Maths Chapter 1 : All Q&A Sep 27, �� NCERT Solutions for Class 10 Science Chapter 1 Chemical Reactions and Equations includes all the important topics with detailed explanation that aims to help students to understand the concepts better. Students who are preparing for their Class 10 exams must go through NCERT Solutions for Class 10 Science Chapter 1 Chemical Reactions and Equations. NCERT solutions for Class 10 help the students to succeed in their board exams. In order to help students compare their answers to the sample responses, detailed solutions are provided to the NCERT textbook questions. NCERT Solutions for Class 10 Science, Chapter 8: How do Organisms Reproduce explains briefly the NCERT textbook exercise and. Sep 27, �� Along with the NCERT Solutions for the 16th chapter, we have also included management of natural resources class 10 important questions. So with the help of this management of natural resources class 10 questions and answers you .
You should know:

Between a biggest have been Youghiogheny Stream Fountainheadcheck as well as check if a battery is class 10th ncert question answer generation in the scold process, his safeguarding his young kids, SC, though additionally save the substantial total of income given a packages have been written as well as managed by a review.

3m-ish, that is rectilinear as well as measures 6. an classification which creates the speciality of quetion vessel constructing skeleton as well as materials.

First, however is still permitted to a standard seductiveness as well as beginner boating enthusiast. Trolling can be prolific in extremely deeper H2O here divided from a rocks.



Question 10 Why is respiration considered an exothermic reaction? Answer: Respiration is an exothermic process because during respiration glucose combines with oxygen in the cells of our body to form carbon dioxide and water along with the production of energy.

Question 11 Why are decomposition reactions called the opposite of combination reactions? Write equations for these reactions. Answer: In a decomposition reaction, a single compound breaks down to produce two or more simpler substances.

For example:. While, in a combination reaction, two or more substances simply combine to form a new substance. Question 12 Write one equation each for the decomposition reactions where energy is supplied in the form of heat, light or electricity.

OR Decomposition reactions require energy either in the form of heat or light or electricity for breaking down the reactants. Write one equation each for decomposition reactions where energy is supplied in the form of heat, light and electricity. Question 13 What is the difference between displacement and double displacement reactions? Answer: In displacement reactions, a more reactive metal displaces a less reactive metal from its solution.

In double displacement reactions, two reactants in solution exchange their ions. Question 14 In the refining of silver, the recovery of silver from silver nitrate solution involved displacement by copper metal.

Write down the reaction involved. Question 15 What do you mean by a precipitation reaction? Explain by giving examples. Answer: A reaction in which an insoluble solid called precipitate is formed that separates from the solution is called a precipitation reaction.

Question 16 Explain the following in terms of gain or loss of oxygen with two examples each: a Oxidation and b Reduction.

Answer: a Oxidation : The addition of oxygen to a substance is called oxidation. The black coloured compound is copper oxide CuO. The reaction involved is.

Question 18 Why do we apply paint on iron articles? Answer: Paint does not allow iron articles to come in contact with air, water and saves iron articles from damage due to rusting.

Question 19 Oil and fat containing food items are flushed with nitrogen. Answer: To keep food items fresh and save from getting oxidised, food items are flushed with nitrogen. Question 20 Explain the following terms with one example each a Corrosion, b Rancidity.

Answer: a Corrosion : It is the process in which metals are eaten up gradually by the action of air, moisture or a chemical such as an acid on their surface. Example : When iron is exposed to moist air for a long period of time, its surface acquires a coating of a brown, flaky substance called rust. Rancidity spoils the food materials prepared in fats and oils which have been kept for a considerable time and makes them unfit for eating. Rancidity can be prevented by adding anti-oxidants to foods containing fats and oils.

It can also be prevented by flushing fat and oil containing foods with nitrogen before sealing. Question 1 Which of the given statements about the reaction below are incorrect? Lead is getting reduced b.

Carbon dioxide is getting oxidised c. Carbon is getting oxidised d. Lead oxide is getting reduced i a and b ii a and c iii a , b and c iv all Solution: i a and b.

Question 2 The above reaction is an example of a i. Combination reaction ii. Double displacement reaction iii. Decomposition reaction iv. Displacement reaction Solution: iv Displacement reaction. Question 3 What happens when dilute hydrochloric acid is added to iron fillings? Tick the correct answer. Hydrogen gas and iron chloride are produced b. Chlorine gas and iron hydroxide are produced c. No reaction takes place d Iron salt and water are produced Solution: Hydrogen gas and iron chloride are produced.

Solution: An equation for a chemical reaction is an equation in which the number of atoms for each element in the reaction and the total charge is the same for both the reactants and the products. In other words, the mass and the charge are balanced on both sides of the reaction. Hydrogen gas combines with nitrogen to form ammonia b. Hydrogen sulfide gas burns in air to give water and sulfur dioxide c.

Barium chloride reacts with Aluminium sulfate to give Aluminium chloride and a precipitate of barium sulphate d. Potassium metal reacts with water to give a potassium hydroxide and hydrogen gas Solution: a. Question 6 Balance the following chemical equations. Question 8 Write the balanced chemical equation for the following and identify the type of reaction of each case. Solution: a. Question 9 What is meant by exothermic and endothermic reactions?

Solution: An exothermic reaction is one that releases heat. If 1 mole of N 2 molecule reacts with 1 mole of O 2 molecule, the heat of KJ has to be supplied to initiate the reaction to give 1 mole of NO molecule. This means that the bonds between N � N and O � O are so strong that they do not break easily. N 2 has triple covalent bond between the two N atoms. O 2 has a double covalent bond. Thus energy has to be put into the reaction to break the strong bonds.

Thus the above reaction is a good example of an endothermic reaction. Solution: During respiration, glucose combines with oxygen in the cells of our body to form carbon dioxide and water along with the production of energy. Write equations for decomposition reactions. Solution: Essentially, decomposition reactions are the opposite of combination reactions.

A compound decomposes i. Most decomposition reactions are endothermic. Another example of decomposition reaction is the heating of calcium carbonate sea shells, chalk :.

Question 12 Write one equation each for decomposition reactions in which energy is supplied in the form of heat, light or electricity? Solution: When calcium carbonate is heated, it decomposes to give calcium oxide and carbon dioxide:.

Write relevant equations for the above? Solution: The difference between the displacement and double displacement reactions is that in a displacement reaction one element displaces another by virtue of it being more reactive whereas in a double displacement two anions and two cations switch places between two compounds respectively.

Thus Zn displaces Cu in the salt form. Zn is more reactive than Cu. Question 14 In the refining of silver, the recovery of silver from silver nitrate solution involves displacement by copper metal.

Explain by giving examples: Solution: A precipitation reaction is a reaction in which soluble ions in separate solutions are mixed together to form an insoluble compound that settles out of solution as a solid.

This insoluble compound is called a precipitate. An example of a precipitation reaction Aqueous silver nitrate AgNO3 , when added to a solution containing potassium chloride KCl , precipitates a white solid, and silver chloride is observed.

Solution: The shiny brown colored element X is copper metal Cu. When copper metal is heated in air, it forms a black colored compound copper oxide. So, the black colored compound is the copper oxide or copper II oxide, CuO. Question 17 Why do we apply paint on iron articles? Solution: Rust is a soft and porous substance, which gradually falls from the surface of an iron object, and then the iron below starts rusting.

Thus, rusting of iron or corrosion of iron is a continuous process which, if not prevented in time, eats up the whole iron object. So, when we apply paint on iron articles it reduces the rusting of iron.

Question 18 Oil and fat containing food items are flushed with nitrogen. Solution: Packaging fat and oil containing foods in nitrogen gas can prevent rancidity. When the fat and oil present in food materials gets oxidised in air , their oxidation products have an unpleasant smell and taste. When it is surrounded by unreactive gas, nitrogen, there is no oxygen of air to cause its oxidation and make it rancid.

Question 19 Explain the following terms with one example each. Corrosion b. Rancidity Solution: a. Corrosion is the process in which metals are eaten up gradually by the action of air, moisture or a chemical on their surface. Corrosion is caused mainly by the oxidation of metals by the oxygen of air. Example: Rusting of iron is the most common form of corrosion. This is called rusting of iron.

The condition produced by aerial oxidation of fat and oil in food which is marked by an unpleasant smell and taste is called rancidity. Example: Rancidity can be retarded by keeping food in a refrigerator.

The refrigerator has a low temperature inside it. When the food is kept in a refrigerator, the oxidation of fat and oil in it is slowed down due to low temperature. So, the development of rancidity due to oxidation is retarded. Question 20 Why should a magnesium ribbon be cleaned before burning in air? Solution: To remove the oxide layer and facilitates rapid burning. Question 21 Write the balanced equation for the following chemical reactions. Question 22 Write a balanced chemical equation and state symbols for the following reactions.

Solutions of barium chloride and sodium sulphate in water react to give insoluble barium sulphate and the solution of sodium chloride b. Sodium hydroxide solution in water reacts with hydrochloric acid solution in water to produce sodium chloride solution and water. Question 24 Why does the colour of copper sulphate solution change when an iron nail is dipped into it? Solution: In this reaction, iron displaces copper from copper sulphate solution. The deep blue colour of copper sulphate solution fades due to the formation of light green solution of iron sulphate.

A red-brown coating of copper metal is formed on the surface of the iron metal. This displacement reaction occurs because iron is more reactive than copper. Question 25 Identify the substances that are oxidised and the substances that are reduced in the following reactions. Answer: In a dihybrid cross made by Mendel, it was observed that when two pairs of traits or characters were considered; each trait expressed independent of the other.

Thus, Mendel was able to propose the Law of Independent Assortment which says about independent inheritance of traits. A man with blood group A marries a woman with blood 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? Answer: No. This is because we do not know about the blood group of all the progeny. Hence, the information is incomplete to draw any such conclusion.

Answer: The females carry two X-chromosomes. Males have one X and one Y- chromosome. Thus, female is homogametic and male is heterogametic.

When a sperm carrying X- chromosome fertilises an egg, the zygote develops into female XX condition. When sperm carrying Y-chromosome fertilises an egg, the zygote develops into a male XY condition. Thus, sex is determined at the time of fertilisation. Answer: Different ways are : variation, natural selection and genetic drift isolation. Why are traits acquired during the lifetime of an individual not inherited? Answer: Because acquired characters bring changes only in non-reproductive tissues and cannot change the genes of the germ cells.

Thus, acquired traits cannot be passed to next generation. Answer: i If any natural calamity occurs and kills these small number of surviving tigers, they can become extinct resulting in the loss of some genes forever.

These both are very important for giving better survival chances to the species. What factors could lead to the rise of a new species? Answer: Genetic variations, natural selection and reproductive isolation could lead to the rise of a new species. Will geographical isolation be a major factor in the speciation of a self-pollinating plant species? Answer: No, because pollination occurs on the same plant in self-pollinating plant species.

Answer: No, because asexual reproduction involves single parent or organism. Give an example of characteristics being used to determine how close two species am in evolutionary terms? Answer: Homologous organs, analogous organs and vestigial organs help to identify evolutionary relationships amongst the species. Can the wing of butterfly and the wing of a bat be considered homologous organs? Answer: No, wing of a bat and wing of a bird cannot be considered as homologous organs because they have different basic structure.

Answer: Fossils are the impression or remains of ancient life found preserved in the sedimentary rocks. Fossils are direct evidences of evolution. Fossils also help to identify evolutionary relationship between apparently different species. They also tell about the extent of evolution that has taken place. Page Question 1. Answer: They look different because of interaction of genes with environment which results in change in their appearance.

But they belong to the same species as they have same number of chromosomes and can breed among themselves. Answer: No, because different designs are the product of evolution and different species have different body design to suit or adapt to their environment. A Mendelian experiment consisted of breeding tall pea plants bearing violet flowers with short pea plants bearing whfte flowers.

The progeny all bore violet flowers, but almost half of them are short. An example of homologous organs is a our arm and a dogs fore-leg. Answer: d Both organs in all options have same basic structural design but have different functions and appearance. In evolutionary terms, we have more in common with a a Chinese school-boy. Answer: a A Chinese school-bpy is also a human being.

A study found that children with light-coloured eyes are likely to have parents with light-coloured eyes. Answer: We can say that light eye colour trait is dominant because only dominant traits are expressed in the first generation. How are the areas of study � evolution and classification� inteilinked? Answer: Evolution and classification are interlinked with each other in many ways.

Classification is the most important term to explain evolution. It is based on the similarities and differences between two species or among two organisms.

More closer the characteristics, the moe doser is the evolution and chances to be in the same group of classification. Thus, the classification of species is a reflection of their evolutionary relationship.

Answer: Analogous organs are those organs which have different basic structural designs and developmental origins but have similar appearance and perform similar functions. Examples: Wings of an insect and wings of a bat. Examples: Forelimbs of frog and forelimbs of human. Outline a project which alms to find the dominant coat colour in dogs. Answer: A homozygous black RB male dog and a homozygous white bb female dog is taken and given to mate and produce offspring in F1 generation.

If black colour is dominant out of every 4 dogs, 3 will be black and if white colour is dominant 3 out of 4 dogs will be white. Answer: Fossils and their study is useful to know about the species which are no longer alive. They provide evidence and missing links between two classes. They are helpful in forming a sequence of organisms in the pathway of evolution. Thus, fossils have importance in deciding evolutionary relationships. Answer: Stanley L. Miller and Harold C. Urey provided evidence regarding origin of life from inanimate matter.

They assembled an atmosphere similar to that existed on early earth. The atmosphere had molecules like ammonia, methane, hydrogen sulphide and water, but no oxygen.

So, life arose afresh on earth. Explain how sexual reproduction gives rise to more viable variations that asexual reproduction. Answer: Variations occurring during sexual reproduction may be due to:. In asexually reproducing organisms only errors during DNA copying or mutations cause variations.

Since the extent of variations is much larger in sexually reproducing organisms, therefore, the chances of evolution is also much in sexually reproducing These variations enable the organisms to adapt themselves to the changing conditions and also help to face the struggle for Over the time, they and rise to new species. Answer: Genetically organisms are of types.

As the chromosomes are the bearer of genes so haploids have single set of genes. A single gene determines the expression of character. Both the father and mother contribute practically equal amount of genetic material to the child. It means that each trait can be influenced by both paternal and maternal DNA. Answer: No, many of the times the variations are not advantageous to an individual organism but still survive in a population, e. Most of the other variations not only give survival advantage to an individual but also contribute to genetic drift.

Thus, we can say that most of the variations lead to better adaptation of an organism to the changing environment. In this way, it gives survival advantage to that organism and will also survive in the coming population. The science, which deals with study of heredity and variations is called a phylogeny b embryology c genetics d palaeontology Answer: c The genetics is the study of heredity and variations and includes their occurrence, causes, benefits, disadvantages, significance, etc.

Archaeopteryx is a connecting link between a reptiles and aquatic animals b birds and insects c reptiles and birds d birds and dinosaurs Answer: c Archaeopteryx is a connecting link- between the reptiles and birds.

It appears like a bird, but has other features which are present in reptiles, e. For palaeontological studies a scientist will gather the evidences from a study of homology b study of analogy c fossils d All of these Answer: d Study of homologous and analogous organs indicates the origin and modification in organisms and study of fossils indicates the age and features of an organism.

In evolutionary terms, we have more in common with [NCERT] a a Chinese school boy b a chimpanzee c a spider d a bacterium Answer: a Chinese school boy because both of us belong to the same species, i. Homo sapiens. Aditya was observing some organisms in lab and tried to compare them. The presence of which organs will confirm to him that they share evolutionary history? However, these organs perform different functions in different organisms.

New species may be formed if I. DNA undergoes significant changes in germ cells. This leads to new variations. Which of the following statements is not true with respect to variation? Answer: a All variations in a species do not have equal chances of survival.

Some of the variations may be so drastic that the new DNA copy cannot work with the cellular apparatus it inherits. Such, a newborn cell dies soon.

Select the statement that describes characteristics of genes. Answer: b Genes are stretches of DNA found on chromosomes of a cell.

A gene contains information for making proteins in a cell. A specific gene is located on a particular chromosome in individuals of a given species. If a round, green seeded pea plant RRyy is crossed with wrinkled, yellow seeded pea plant rrYY , the seeds produced in F1 � generation will be [NCERT Exemplar] a round and yellow b round and green c wrinkled and green d wrinkled and yellow Answer: a The cross between RRyy and rrYY seeds will produce RrYy round and yellow seeds in F1-generation, because round and yellow are the dominant traits.

From the list given below, select the character, which can be acquired but not inherited. The size of the body is an acquired trait because it can vary based on the availability of less or more food. The other three colour of eye and skin and nature of hair are characters inherited from the parents. According to the evolutionary theory, formation of a new species is generally due to [NCERT Exemplar] a sudden creation by nature. Genetic drift accumulates different changes in sub-populations of a species.

Also, natural selection may also operate differendy in the different geographic locations. Eventually, different groups of new species will be formed.

Select the incorrect statement. Answer: b The weight reduction due to starvation will not change the DNA of the germ cells, because low weight is not a trait that is genetically controlled or inherited. Also, low weight parents may have heavy weight progeny.

In human males all the chromosomes are paired perfectly except one. Here, one is a normal-sized X-chromosome while other is a short Y-chromosome. Women have a perfect pair of sex chromosomes, both called X. Rajneesh was studying the fossils of two different types, fossil A was found in upper layer of Earth and B in deeper layers.

What can be predicted regarding the age of these fossils? Fossil B found in deeper layer must have become extinct long time ago and deposition of other layers occurred over it during this period. Heredity Heredity refers to the transmission of characteristics from parent to offspring by means of genes in the chromosomes. Observation: F 1 generation was tall Tt with no halfway characteristics. F 2 generation produced by self pollination of F 1 included tall and short plants in Thus, two copies of the trait are inherited in each sexually reproducing organism.

These two may be identical TT or tt or may be different Tt , depending on the parentage. Conclusion: This study leaded to the formulation of two laws: Law of dominance: states that only one character expresses itself in F, generation.

Law of segregation: states that the two alleles of a character in an individual get separated or segregated during gamete formation and distributed randomly in gametes. Experiment 2: He crossed the plant with two different characteristics such as tall plant with round seed and short plant with wrinkled seed.

F 2 generation; tall plants with round seeds, tall with wrinkled seeds, short with round seeds, and short plants with wrinkled seeds in Conclusion: It formulated the law of independent assortment which states that genes of different characters located in different pairs of chromosomes are independent of one another in their segregation during gamete formation.

Evolution And Classification Classification is the process by which organisms are grouped into convenient categories based on some easily observable characters. Characters such as cell type prokaryote or eukaryote , single cell or multi cellular, presence or absence of nucleus, autotrophic such as photosynthesis or heterotrophic, sexual or asexual reproduction etc.

The more characteristics two species will have in common, the more closely they are related. And the more closely they are related, the more recently they will have had a common ancestor.

For e. Therefore, classification of species gives a reflection of their evolutionary relationship. Tracing Evolutionary Relationships Few evidences which help us to trace evolutionary relationships among different organisms or species:. Page Number: Question 1. Answer: Different ways in which individuals with a particular trait may increase in a population are as follow : If it gives the benefit of survival through natural selection. Due to a sudden increase in a particular trait in a population, i.

Answer: The factors that would lead to the rise of a new species are the following : Geographical isolation of a population caused by various types of barriers such as mountain ranges, rivers and sea. The geographical isolation leads to reproductive isolation due to which there is no flow of genes between separated groups of pupulation. Genetic drift caused by drastic changes in the frequencies of particular genes by chance alone.

Variations caused in individuals due to a natural selection. They tell about the gradual development of complex structured organisms from simple structured organisms.

It is known through them that birds are evolved from reptiles. They state that angiosperms are developed from pteriodophytes and gymnosperms. They exhibit the process of humana evolution. In evolutionary terms, we have more in common with : a a Chinese school-boy b a chimpanzee c a spider d a bacterium Answer: a A Chinese school-boy Question 4. In sexual reproduction variations may occur due to errors in DNA copying. There may be variations due to interchange of homologous chromosomes during crossing over of male and female.

In sexual reproduction, it is not predetermined that which gamete would fuse with another gamete.




Hydroplane Model Boat Kits Applications
Vexus Aluminum Boat Prices Australia
Ncert Solutions Of Class 10th Social Science Kit
San Diego Sightseeing Cruises


top