Biology Class 10 important questions

Q1.Which natural resources are called the “ biodiversity hot spots ”? How these hot spots maintain ecological balance ?
Q2.Explain with the help of labelled diagrams the development that takes place in each of the body parts of a Planaria where body is cut into three pieces. None this process and give an example of an organism in which a similar process can be observed.
Q3.List any four methods of contraception used b y humans. How does the use of three methods have a direct effect on the heath and prosperity of a family?
Q4.A. How does speciation take place?
B. Define the term GENE.
C. The gene for red hair is recessive to the gene for black hair. What will be the hair colour of a child if he inherits a gene for red colour from his mother and a gene for black hair from his father? Express with the help of flow chart
Q5.“Different species use different strategies to determine sex of a new born individual. It can be environmental cues or genetically determined”. Justify this statement giving reason/example
Q6.What are homologous organs? How do they provide evi dence in support of evolution?
Q7.Explain double fertilization in plants.
Q8.Name one organ analogous to the wing of the bird. W hy are they both analogous? Can you include the wing of bat also with them under the sa me category? Give reason.
Q9.Discuss in brief the various modes of reproduction used by single organisms.
Q10.DDT that was sprayed in minute amount on food plant s was detected in high concentration in man? How did it happen? Explain.
Q11.State three laws of Mendel.
Q12.Mention any four details that can be inferred about organisms from their fossils.
Q13.Energy transfer is said to be unidirectional where as biochemical transfer is said be cyclic. Why?
Q15.What are the advantages and disadvantages of self a nd cross pollination? Which of them is better and why?
Q16.How has the method of ‘artificial selection’ by hum ans helped in the evolution of different vegetables?
Q17.What is ten percent law? Explain with an example ho w energy flows through different trophic levels?

Class X Physics SA 2 Important Questions

Q1.When a c oncave mirror is placed facing the Sun, the Sun’s rays converge to a point 10 cm from the mirror. Now, if you place a 2 cm long candles flame 20 cm away on the principal axis of the mirror, where would you place a screen to obtain the image of the candle? What would see the size of the image? Draw a ray diagram to justify your answer.

Class X Chemistry SA 2 Important Questions

1.Name the product formed beside soap that is obtaine d during saponification process.
2.Define Mendeleev’s Periodic Law. Give two advantage s of Mendeleev’s Periodic Table.
3.Why was it necessary to change the basis of classif ication from atomic mass to atomic number. 4.(a) A compound X is formed by the reaction of carboxyli c acid having the molecular formula C 2 H 4 O 2 and alcohol (Y) in the presence of conc. H 2 SO 4 . The same carboxylic acid is obtained by the oxidation of alcohol (Y). Name the compounds X and Y. Give the chemical equation for the reaction.