List of top Questions asked in CBSE Compartment Exam Class X

What is meant by biomagnification?

Consider the following statements: 
Every step in a food chain is called a trophic level. 
Decomposers convert complex organic matter into simple substances that mix with the soil. 
In a food chain, energy increases from lower to higher trophic level.
Interlinking of multiple food chains forms a food web. 
Which of the above statements are correct?

In the bread mould (Rhizopus), the structures labeled A and B are respectively:
In plants, waste products like resin and gum are stored in:
Select the hydrocarbon from the following which contains one C$\equiv$C triple bond and one C–C single bond:
The acid present in nettle leaves is:
A few drops of turmeric solution are added to a colorless liquid. If the liquid turns red in color, the liquid could be:
Write the name of the part of the human female reproductive system where the following functions take place:
Maturation of ovum
Fertilization of ovum with sperm
Zygote formation
What happens when:
The ovum is fertilized?
The ovum is not fertilized?
Explain each with an example:
(1) Unisexual flower
(2) Bisexual flower
Identify the labeled parts A, B, C, and D in the given diagram of a flower.
"Pollination can occur without fertilization, but fertilization cannot occur without pollination." Justify this statement.
Give one example each of (i) a natural ecosystem and (ii) an artificial (man-made) ecosystem.
A certain aqueous solution turns blue litmus red. On adding an excess of which of the following solutions will this change be reversed?
Lemon juice
Magnesium hydroxide
Vinegar
Calcium sulphate
Which of the following will turn phenolphthalein pink?
CH$_3$COOH
Ca(OH)$_2$
HCl
NaOH
Write the name and formula of a gas whose solution is basic.
Why is a basic solution used to treat a bee sting?
Name the acids present in:
Tomato
Tamarind (imli)
Define crystalline water.
(i) Why do the members of a homologous series show similar chemical properties?
(ii) What is the difference in number of carbon and hydrogen atoms between two consecutive members of a homologous series?
Give one example each of (i) Alkanes, (ii) Alcohols, (iii) Aldehydes.
(i) Explain why carbon forms strong bonds with other elements.
(ii) Why do covalent compounds have low melting and boiling points?
(iii) Draw electron dot structure of chlorine (atomic number 17).
(a) Write the names of glands located in the stomach and list the digestive enzymes secreted by them.
Even though the liver has no digestive enzymes, it plays an important role in digestion. Explain.
Differentiate between a solenoid and a circular coil.
Explain how a solenoid can be made in a school lab.