List of practice Questions

Let P be a skew-symmetric matrix of order 3. If \( \det(P) = \alpha \), then \( (2025)^\alpha \) is
If \( \vec{PQ} \times \vec{PR} = 4 \hat{i} + 8 \hat{j} - 8 \hat{k} \), then the area \( (\triangle PQR) \) is
In the following probability distribution, the value of p is:
probability distribution
The values of \(x\) for which the angle between the vectors \( \vec{a} = 2x^2 \hat{i} + 4x \hat{j} + \hat{k} \) and \( \vec{b} = 7 \hat{i} - 2 \hat{j} + x \hat{k} \) is obtuse, is:
Sweet potato and potato represent a certain type of evolution. Select the correct combination of terms to explain the evolution.

A block of certain mass is placed on a rough floor. The coefficients of static and kinetic friction between the block and the floor are 0.4 and 0.25 respectively. A constant horizontal force \( F = 20 \, \text{N} \) acts on it so that the velocity of the block varies with time according to the following graph. The mass of the block is nearly (Take \( g = 10 \, \text{m/s}^2 \)): 

The cloning site present in the \( \textit{rop}\) site of \(\textit{E. coli}\) cloning vector pBR322 is:

Assertion (A): In dihybrid crosses involving sex-linked genes in \(\textit{Drosophila}\), generation of non-parental gene combinations are observed 
Reason (R): Two genes present on different chromosomes show linkage and recombination in \(\textit{Drosophila.}\)

Study the given molecular structure of a double-stranded polynucleotide chain of DNA and answer the questions that follow.
molecular structure of a double-stranded polynucleotide

How is the interaction between \(\textit{Ophrys}\) and its specific bee pollinator one of the best examples of co-evolution? Explain.

The basic scheme of the essential steps involved in the process of recombinant DNA technology is summarised below in the form of a flow diagram. Study the given flow diagram and answer the questions that follow.
essential steps involved in the process of recombinant DNA
Flowering plants with hermaphrodite flowers have developed many reproductive strategies to ensure cross-pollination. Study the given outbreeding devices adopted by certain flowering plants and answer the questions that follow.
Flowering plants
Note: All plants belong to the same species. × - No pollen tube growth/inhibition of pollen germination on stigma. ✓ - Pollen germination on stigma.

Explain how the addition of lactose in the medium regulates the switching on of the \(\textit{lac}\) operon in bacteria.

Read the following passage and answer the questions that follow.
Prevention is the frontline response to drug use. Effective interventions address the underlying conditions contributing to drug use, such as a lack of connection to family or community, instability, insecurity, trauma, mental health issues, etc. When addressed, these factors can effectively prevent the initiation of drug use and the progression to drug use disorders. Study the few key figures of drug use given below and answer the questions that follow.
Read the following passage and answer the questions that follow.
According to evolutionary theory, every evolutionary change involves the substitution of a new gene for the old one and the new allele arises from the old one. Continuous accumulation of changes in the DNA coding for proteins leads to evolutionary differences. The chemical composition of DNA is basically the same in all living beings, except for differences in the sequence of nitrogenous bases. Given below are percentage relative similarities between human DNA and DNA of other vertebrates:
evolutionary theory, every evolutionary change involves the substitution of a

The cloning site present in the ampicillin resistance gene of \( \textit{E. coli}\) cloning vector pBR322 is :

Assertion (A) : In dihybrid crosses involving sex-linked genes in \(\textit{Drosophila}\), \(F_2\) generation of non-parental gene combinations are observed. 
Reason (R) : Two genes present on different chromosomes show linkage and recombination in \(\textit{Drosophila.}\)

Assertion (A) : An antibody is a protein molecule made by the lymphocytes.
Reason (R) : An antibody binds to a specific foreign antigen and neutralizes its odd effects.
Assertion (A) : Isolated single cells can be fused to produce somatic hybrids.
Reason (R) : Cells selected for somatic hybridisation have desirable characters.
Assertion (A) : Male contraceptive ‘Nirodh’ works on the principle of avoiding chances of ovum and sperm meeting.
Reason (R) : It is made of thin rubber/latex sheath and is used to cover the penis before coitus.
Certain viruses used as biological control agents belong to the genus :
In a translational unit UTRs are present at :
Given below are a few statements with reference to the human sperm.
1. Sperm head contains a large nucleus and a lot of cytoplasm.
2. Mitochondria in the middle piece of a sperm provides ATP for the sperm motility.
3. Posterior part of the sperm head is covered by acrosome.
4. Spermatids undergo maturation into spermatozoa by the process of spermiogenesis.
5. Acrosomal secretions help in the entry of the sperm into the ovum at the time of fertilization.
Choose the option with all true statements from the given options :
A normal couple produces half the sons as haemophilic and half the daughters as carriers. Choose the option that correctly indicates the chromosome on which the gene for this trait is located.
The lymphoid organ located within the lining of respiratory, digestive and urogenital tract is :