List of top Questions asked in CBSE CLASS XII

“Farmers prefer apomictic seeds to hybrid seeds.” Justify giving two reasons.
The question consist of two statements – Assertion (A) and Reason (R). Answer these questions selecting the appropriate option given below:
The question consist of two statements – Assertion (A) and Reason (R). Answer these questions selecting the appropriate option given below:
The question consist of two statements – Assertion (A) and Reason (R). Answer these questions selecting the appropriate option given below:
The question consist of two statements – Assertion (A) and Reason (R). Answer these questions selecting the appropriate option given below:
If the sequence of nitrogen bases of the coding strand in a transcription unit is 5\(\prime\)–ATGAATG–3\(\prime\), the sequence of bases in its RNA transcript would be:
If both the parents are carriers for thalassaemia, the chances of an afflicted child to be born to them is:
Match the following genes of the lac operon listed in column ‘A’ with their respective products listed in column ‘B’: \begin{center} \begin{tabular}{|c|c|} \hline Column A (Gene) & Column B (Product)
\hline a. ‘i’ gene & (i) \(\beta\)-galactosidase
b. ‘z’ gene & (ii) Lac permease
c. ‘a’ gene & (iii) Repressor
d. ‘y’ gene & (iv) Transacetylase
\hline \end{tabular} \end{center} Select the correct option:
Study the pedigree chart of a family showing the inheritance pattern of a certain disorder. Select the option that correctly identifies the nature of the trait depicted in the pedigree chart.
Identify the correct labellings in the figure of a fertilised embryo sac of an angiosperm given below:
A phenomenon where a male insect mistakenly identified the patterns of an orchid flower as the female insect partner, and tries to copulate and thereby pollinates the flower is said to be:
Which one of the following statements is correct in the context of observing DNA separation by agarose gel electrophoresis?
During biological treatment of sewage, the masses of bacteria held together by fungal filaments to form mesh-like structures are called:
Interferons are proteins secreted by:
Observe the schematic representation of assisted reproductive technology given below:
Identify the most appropriate technique depicted in the above diagram.
A person with trisomy of 21st chromosome shows:
(i) Furrowed tongue
(ii) Characteristic palm crease
(iii) Rudimentary ovaries
(iv) Gynaecomastia
Select the correct option from the choices given below:
A single gene that controls the expression of more than one trait is said to show:
If \(A = \begin{bmatrix} 1 & -2 & 0 \\ 2 & -1 & -1 \\ 0 & -2 & 1 \end{bmatrix}\), find \(A^{-1}\) and use it to solve the following system of equations: \[ x - 2y = 10, \quad 2x - y - z = 8, \quad -2y + z = 7. \]
Find: \[ \int_{\pi/6}^{\pi/3} \frac{\sin x + \cos x}{\sqrt{\sin 2x}} \, dx. \]
(a) Evaluate: \[ \int_{0}^{\pi/2} e^x \left( \frac{1 + \sin x}{1 + \cos x} \right) dx. \]
(b) If \(y = (\tan x)^x\), then find \(\frac{dy}{dx}\).
(a) If \(\sqrt{1 - x^2} + \sqrt{1 - y^2} = a(x - y)\), prove that \(\frac{dy}{dx} = \sqrt{\frac{1 - y^2}{1 - x^2}}\).
Solve the following linear programming problem graphically: \[ \text{Maximise } z = 5x + 4y \] subject to the constraints: \[ x + 2y \geq 4, \quad 3x + y \leq 6, \quad x + y \leq 4, \quad x, y \geq 0. \]
Find the general solution of the differential equation: \[ \frac{dy}{dx} = \frac{x^2 + y^2}{2xy}. \]
(b) Evaluate: \[ \int_{1}^{3} \left(|x - 1| + |x - 2| + |x - 3|\right) \, dx. \]