List of top Questions asked in CBSE CLASS XII

Assertion (A): In some species of asteraceae and grasses, seeds are formed without fertilization.
Reason (R): Formation of fruit without fertilization is called parthenocarpy.
Arrange the given important steps of decomposition in their correct order of occurrence in the breakdown of complex organic matter and explain the fourth step in the process.
\( \fbox{Catabolism}\) \(\fbox{Leaching} \fbox{Fragmentation} \fbox{Mineralisation} \fbox{Humification}\)
Assertion (A): Isolated single cells can be fused to produce somatic hybrids.
Reason (R): Cells selected for somatic hybridisation have desirable characters.
The animals that evolved into the first amphibians during evolutionary history were:
Assertion (A): In humans, filariasis is characterized by inflammation of the lower limbs.
Reason (R): Filarial worm usually lives in the lymphatic vessels of the lower limbs.
Bacteria growing anaerobically on cellulosic material produce large amounts of which gases? Select the correct option.
Inheritance of which of the following traits is shown in the cross given below?

Autosomal recessive trait

Choose the correct option from the following:
Select the statements that are true for the embryo of the flowering plants from the given options:
1. The zygote forms a proembryo and subsequently heart-shaped, globular and mature embryo.
2. Most zygotes divide to form embryo only after a certain amount of endosperm is formed.
3. The embryo develops at the micropylar end of the embryo sac.
4. A typical dicotyledonous embryo consists of an embryonal axis and a scutellum.
Choose the correct option from the following:
Human Immunodeficiency Virus is a member of the group of viruses known as:
Some of the important goals of HGP are given below. Choose the correct goal of HGP.
In a DNA, the percentage of thymine is 20. What is the percentage of guanine in it?
Given below are few statements with reference to the human male reproductive system:
1. Paired seminal vesicles, prostate gland and bulbourethral gland constitute the male accessory glands.
2. Secretions of the male accessory glands constitute the seminal plasma.
3. Secretions of the bulbourethral glands help in the lubrication of the penis.
4. Enlarged end of the the penis is known as foreskin.
5. Seminal plasma is rich in fructose, calcium and certain enzymes.
Choose the option with all true statements from the given options:
When a pure tall pea plant (\textit{Pisum sativum}) with green pod is crossed with a dwarf pea plant with yellow pod, how many dwarf pea plants, out of 16, will be produced in the F\textsubscript{2 generation?}

Derry in On the Face of it is a victim of self-pity. Analyse Derry’s behaviour in the light of the above statement.
 

Select the correct option from those given in brackets, to fill in the blank: The incident made the speaker realize that the discrimination was ____ (dehumanizing / elevating).
Mr. Lamb: “____ you thought it has an empty house, but inside it’s full.” What do these words tell you about Mr. Lamb? (On the Face of It)
“Not at all,” Sadao said. “It is inconvenient to have you here any longer.” (The Enemy) What image do you form of Dr. Sadao based on the above remark?
Complete the following suitably: On the days when there was a ‘crowd-shooting’. By the phrase ‘crowd-shooting’, the author refers to _____ .
What is the significance of the third level? ( Third Level)

How did Tishani Doshi’s visit to Antarctica as part of the Students on Ice Programme make her realise the importance of preserving the Earth? (Journey to the End of the Earth) 
 

What image of the Tiger King is revealed in the diamond ring episode?
“In that short time, we’ve managed to create quite a ruckus.” What does Tishani Doshi refer to by ‘ruckus’?
The vapour pressure of a solvent at 283 K is 100 mm Hg. Calculate the vapour pressure of a dilute solution containing 1 mole of a strong electrolyte AB in 50 moles of the solvent at 283 K (assuming complete dissociation of solute AB).
Calculate the potential of Iron electrode in which the concentration of Fe2+ ion is 0.01 M. Given \( E^{\circ}_{\text{Fe}^{2+}/\text{Fe}} = -0.45 \, \text{V at 298 K} \)
[Given: log 10 = 1]
Three point charges, 1 pC each, are kept at the vertices of an equilateral triangle of side 10 cm. Find the net electric field at the centroid of the triangle.