Question : Solutions of Questions on Page Number : 143 Q1 :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? Answer : In asexual reproduction, the reproducing cells produce a copy of their DNA through some chemical reactions. However, this copying of DNA is not accurate and therefore, the newly formed DNA has some variations. Itcan be easily observed in the above figure that in asexual reproduction, very few variations are allowed. Therefore, if a…
Author: Admin
Question : Solutions of Questions on Page Number : 128 Q1 :What is the importance of DNA copying in reproduction? Answer : DNA (Deoxyribonucleic acid) is the genetic material found in the chromosomes, which are present in the nucleus of a cell. The DNA is the information site for making proteins and each specific type of protein leads to a specific type of body design. Thus, it is the DNA molecule that determines the body design of an individual. Therefore, it can be concluded that it is the DNA that gets transferred from parents to offsprings and makes them look…
Question : Solutions of Questions on Page Number : 119 Q1 :What is the difference between a reflex action and walking? Answer : A reflex action is a rapid, automatic response to a stimulus. It does not involve any thinking. For example, we close our eyes immediately when the bright light is focused. Walking, on the other hand, is a voluntary action. It is under our conscious control. NCERT Solutions for Class 10 Science Chapter 7 Q2 :What happens at the synapse between two neurons? Answer : A very small gap that occurs between the last portion of axon of…
Question : Solutions of Questions on Page Number : 95 Q1 :Why is diffusion insufficient to meet the oxygen requirementsof multi-cellular organisms like humans? Answer : Multicellular organisms such as humans possess complex body designs. They have specialised cells and tissues for performing various necessary functions of the body such as intake of food and oxygen. Unlike unicellular organisms, multicellular cells are not in direct contact with the outside environment. Therefore, diffusion cannot meet their oxygen requirements. NCERT Solutions for Class 10 Science Chapter 6 Q2 :What criteria do we use to decide whether something is alive? Answer : Any…
CBSE Solutions for Class 10 Science Chapter 5 Periodic Classification of Elements Question : Solutions of Questions on Page Number : 81 Q1 :Did Dobereiner’s triads also exist in the columns of Newlands’ Octaves? Compare and find out. Answer : Only one triad of Dobereiner’s triads exists in the columns of Newlands’ octaves. The triad formed by the elements Li, Na, and K of Dobereiner’s triads also occurred in the columns of Newlands’ octaves. Dobereiner’s triads Li Ca Cl Na Sr Br K Ba I Newlands’ octaves H Li Be B C N O F Na Mg Al Si P…
NCERT Solutions for Class 10 Science Chapter 4 Question : Solutions of Questions on Page Number : 61 Q1 :What would be the electron dot structure of carbon dioxide which has the formula CO2? Answer : Electron dot structure of CO2 is NCERT Solutions for Class 10 Science Chapter 4 Q2 :What would be the electron dot structure of a molecule of sulphur which is made up of eight atoms of sulphur? (Hint – the eight atoms of sulphur are joined together in the form of a ring.) Answer : Electron dot structure of a sulphur molecule Q3 :How many…
CBSE Solutions for Class 10 Science Chapter 3 Metals and Non-metals Question : Solutions of Questions on Page Number : 40 Q1 :Give an example of a metal which (i) is a liquid at room temperature. (ii) can be easily cut with a knife. (iii) is the best conductor of heat. (iv) is a poor conductor of heat. Answer : (i) Metal that exists in liquid state at room temperature → Mercury (ii) Metal that can be easily cut with a knife → Sodium (iii) Metal that is the best conductor of heat → Silver (iv) Metals that are poor…
CBSE Solutions for Class 10 Science Chapter 2 Acids, Bases and Salts Class Question : Solutions of Questions on Page Number : 18 Q1 : You have been provided with three test tubes. One of them contains distilled water and the other two contain an acidic solution and a basic solution, respectively. If you are given only red litmus paper, how will you identify the contents of each test tube? Answer : If the colour of red litmus paper gets changed to blue, then it is a base and if there is no colour change, then it is either acidic…
CBSE Solutions for Class 10 Science Chapter 1 Chemical Reactions and Equations Question : Solutions of Questions on Page Number : 6 Q1 :Why should a magnesium ribbon be cleaned before it is burnt in air? Answer : Magnesium is an extremely reactive metal. When stored, it reacts with oxygen to form a layer of magnesium oxide on its surface. This layer of magnesium oxide is quite stable and prevents further reaction of magnesium with oxygen. The magnesium ribbon is cleaned by sand paper for removing this layer so that the underlying metal can be exposed to air. NCERT Solutions…
Exercise : Solutions of Questions on Page Number : 131 Q1 : Talk to two workers (For example, construction workers, farm workers, factory workers, workers at any shop) to find out if they are receiving the minimum wages laid down by law. Answer : Attempt this question on your own. Q2 : What are the advantages to foreign companies in setting up production in India? Answer : Foreign companies gain many advantages in setting up production in India. Foremost amongst these is cheap labour. The population boom in India has led to large scale unemployment, as a result, a worker’s…