Some important questions of biology CBSE 10TH CLASS

 Some important questions of biology CBSE 10^TH CLASS

                               

               

Question 1. Which is the information source for making proteins in the cells?

Question 2. List two measures that you would suggest for the better management of water resources.

Question 3. Where does the process of fertilization take place in human females?

Question 4. Why did Mendel choose pea plants for carrying out his experiments on inheritance?

 Question 5. What is meant by acquired trait?

 Question 6. Name the scientist who gave the theory of evolution.

 Question 7. What is an ecosystem? List its two main components?

Question 8. List the two ways which can be used to check the contamination of river water.

Question 9. Draw labelled diagrams to illustrate budding in Hydra.

Question 10. In case of the sexual reproduction the number of chromosomes in parents and their 

offspring is the same. Justify this statement.

Question 11. "Energy flow in a food chain is unidirectional" Justify this statement. How do pesticides enter a food chain and get accumulated in our body?

 Question12. What do you mean by the sexually transmitted diseases? Name one such disease which damages the immune system of human body?

 Question13. What is water harvesting? How can this technique help in the conservation of water?

Question 14. List any four methods of contraception used by humans. How does their use have a direct effect on the health and prosperity of a family?

 Question 15. (a) What do you mean by ‘Evolution’? List the various sources which provide evidences for the evolution.
(b) Give the evidence that the birds have evolved from reptiles.
Question 16.(a) What is ten percent law?

 (b) How much energy will be available to snake in the food chain comprising snake, frog, grasshopper and grass, if 1000 J of energy is available to grass from the sun?

 Question 17.
(a) Define speciation.
(b) Why are the traits acquired during life time of an individual not inherited?

 Question 18. What is the importance of D.N.A replication in asexual reproduction? Why is variation beneficial to the species? Explain with suitable example.

Question 19. (a) Name the respective part of the human female reproductive system:
(i) Where fertilisation of egg takes place.
(ii) Where development of embryo takes place.
(iii) Which provides all the nourishment to the developing foetus. (b) Describe in brief what happens to the zygote after it gets implanted.

 Question 20.
 (a) What is pollination? State and explain its two types. (b) Give one example each of a unisexual and a bisexual flower. (c) Mention the changes a flower undergoes after fertilization.

Question 21. Teacher asked the students to study the different parts of an embryo of a gram seed. The steps likely to be followed are listed below in a haphazard manner:
(i) Soak the gram seeds in plain water and keep them overnight. (ii) Cut open the soaked seed and observe its different parts.
(iii) Take some dry gram seeds in a petri dish. (iv) Drain the excess water.
(v) Cover the soaked seeds with a wet cotton cloth and leave them for a day. The correct sequence of these steps is:
(a) iii, i, v, iv, ii
(b) iii, i, ii, iv, v
(c) iii, iv, v, i, ii
(d) iii, i, iv, v, ii

Question 22. Which one of the following pairs of vegetables is an example of homologous structures?
(a) Potato and sweet potato
(b) Carrot and radish
(c) Carrot and tomato (d) Tomato and radish

Question 23. Which among the following set of organs are homologous:
 (i) Forelimb of a frog and forelimb of a lizard(ii) Forelimb of a bird and forelimb of a human
(iii) Wings of a parrot and wings of a butterfly (iv) Wings of a bird and wings of a bat Choose the correct option:
(a) i and ii (b) ii and iii (c) iii and iv (d) i and iv

Question 24. To determine the percentage of water absorbed by the raisins, before final weighing of the raisins after being kept dipped in water for about two hours, extra water from the soaked raisins is removed by
(a) Dry cotton
(b) Filter paper
(c) Hot air blower (d) Silken cloth

Question 25. Following are given a few statements regarding the process of budding in Yeast: (i) First bud may from a new bud before it gets detached from the parent body.
(ii) Bud grows in a new individual and remains attached to the parent body for life long.
(iii) Nucleus of the parent cell divides into two parts with one part moving into the bud. (iv) The parent cell divides into two daughter cells and the parental identity is lost.
Choose the incorrect statements:
(a) i, ii and iii
(b) ii and iv
(c) iii and iv
(d) ii, iii and iv

 Question 26. Which among the following factors help in confirming the contamination of river water?(i) Measurement of pH of river water
(ii) Presence of chlorine in river water (iii) Existence of diverse life forms in river water
(iv) Presence of coliform bacteria in river water
(a) (i) and (iv)
(b) (ii) and (iii) (c) (iii) and (iv) (d) (ii) and (iv)

                                 {IMPORTANT CHEMSTRY QUESTION}

Some important questions of chemistry CBSE 10TH Class

Some important questions of chemistry CBSE 10^TH Class   

                                             

Question 1. What will be the suitable group in the periodic table for placing Lithium element which is having the atomic number 3?

Question 2. How does the metallic character of the elements of group I changes as we if we move downwards?

Question 3. How many groups and periods are there in the modern periodic table?

Question 4. Write the next higher homolog of each of the following compounds: (i) C2H4 (ii) C4H6

Question 5. What is the reason that carbon atom forms only covalent compounds?

Question 6. On what basis are the elements arranged in the periodic table?

Question 7. The atomic numbers of three elements A, B, and C are 12, 18 and 20 respectively. State, giving reason, which two elements will show similar properties.

Question 8. Write any two anomalies of the Mendeleev’s classification of elements.

Question 9. (i) Why does the soap lose its cleansing action when used in hard water?

(ii) What is hydrogenation of vegetable oils?

Question 10. Explain why a diamond has a high melting point?

Question 11. Discuss the variance of valency and metallic character of elements when moving from left to right in a period?

Question 12. Explain why graphite is used as a lubricant?

Question 13. a) An organic acid X having the molecular formula CH4O2 is a liquid which often freezes during winter time in cold countries. On warming it with methanol in the presence of a few drops of concentrated sulphuric acid, a compound Y with a sweet smell is formed. i) Identify X and Y. Also, write their formulae showing the functional group present on them. ii) Write the chemical equation for the reaction involved. 

Question 14. Write the name and general formula of a chain of hydrocarbons which undergoes an addition reaction with hydrogen. What are the essential conditions required for an addition reaction to take place? Also, write the chemical equation involved giving the name of the reactant and the product formed in such reaction.

Question 15. What do you mean by the functional group present in an organic compound?

 Write the formula of the functional group presents the following compounds: 

(a) Alcohol 

(b) Aldehyde

(c) Ketones 

(d) Carboxylic acid.

Question 16. A carboxylic acid (molecular formula C2H4O) reacts with an alcohol in the presence of an acid catalyst to form a compound 'X'. The alcohol on oxidation with alkaline KMnO4 followed by acidification gives the same carboxylic acid C2H4O2. Identify the addition of ethanoic acid. In which of the test tube or test tubes the flame gets extinguished? 

(a) X and Y 

(b) Y and Z 

(c) X and Z 

(d) only Z

Question 22. 2 mL of acetic acid is added to a test tube containing an equal amount of distilled water and then after shaking its contents, the test tube is kept undisturbed for about 5 minutes. What will you observe in the test tube:

(a) A white precipitate settling at its bottom,

(b) A clear colorless solution,

(c) A layer of water over the layer of acetic acid, or 

(d) A layer of acetic acid over the layer of water.

Question 23. While studying saponification reaction for the preparation of soap, the teacher suggested to a student to add a small quantity of common salt to the reaction mixture. The function of common salt in this reaction is to:

(a) Reduce the alkalinity of the soap, 

(b) Reduce the acidity of the soap, 

(c) Enhance the cleansing capacity of soap, or

(d) Favor precipitation of soap.

Question 24. Which among the following salts will give a light green colored solution when dissolved in water?

(a) CuSO4

(b) FeSO4 

(c) ZnSO4

(d) Al2(SO4)3

Question 25. A student takes 5 ml of tap water in four test tubes and labels them as A, B, C, and D. Then he adds the same amount of four salts, potassium chloride in test tube A, calcium chloride in B, sodium chloride in C, and magnesium chloride in D. Lastly, he adds a few drops soap solution to the four test tubes. In which of the four test tubes formation of scum is observed?

(a) A and B

(b) B and C

(c) B and D 

(d) A and D

                                                  {IMPORTANT FOR BIOLOGY}