In lac operon, a structural gene is-

Read the following passage carefully and answer the given questions.
Cancerous cells just continue to divide giving rise to masses of cells called tumors. Benign tumors normally remain confined to their original location and do not spread to other parts of the body and cause little damage. The malignant tumors, on the other hand are a mass of proliferating cells called neoplastic or tumor cells. Transformation of normal cells into cancerous neoplastic cells may be induced by physical, chemical or biological agents. Ionising radiations like X-rays and gamma rays and non-ionizing radiations like UV cause cancer. Cancer-causing viruses are called oncogenic viruses which have viral oncogenes. The substances to which an immune response is produced are called allergens. The antibodies produced to these are of IgE type. Common examples of allergens are mites in dust, pollens, animal dander, etc. The primary lymphoid organs are bone marrow and thymus. The secondary lymphoid organs provide the sites for interaction of lymphocytes with the antigen, which then proliferate to become effector cells.
Cancer cells divide without any control due to:

In a typical test cross-

Choose the correct match. '+' for beneficial interaction '-' for detrimental and 'O' for neutral effect.

LIst - I		LIst - II
Species A	Species B	Name of Interaction
(A) +	+	(I) Competition
(B) +	-	(II) Mutualism
(C) -	-	(III) Amensalism
(D) -	0	(IV) Predation

Choose the correct answer from the options given below:

Read the passage carefully and answer the questions given along
Our immune system plays the major role in preventing diseases when we are exposed to disease-causing agents. Immunity is of two types: (i) Innate immunity and (ii) Acquired immunity. The human immune system consists of lymphoid organs, tissues, cells and soluble molecules like antibodies. The immune system also plays an important role in allergic reactions, auto-immune diseases and organ transplantation. The primary lymphoid organs are bone marrow and thymus. The secondary lymphoid organs are spleen, lymph nodes, tonsils, Peyer's patches of small intestine and appendix. There is lymphoid tissue also located within the lining of the major tracts (respiratory, digestive and urogenital tracts) called mucosa associated lymphoid tissue (MALT). It is important to note that HIV/AIDS is not spread by mere touch or physical contact; it spreads only through body fluids. AIDS has no cure, prevention is the best option. Adolescence is accompanied by several biological and behavioural changes and surveys and statistics show that use of drugs and alcohol has been on the rise especially among the youth. Factors associated with drug and alcohol abuse among adolescents are a child's natural curiosity, stress, the perception among youth that it is 'cool' or progressive to smoke, media exposure and an unstable or unsupportive family structures and peer pressure. It is best to identify the situations that may push an adolescent towards use of drugs or alcohol, and to take remedial measures well in time.
Mucosa associated lymphoid tissue is absent in the

Which is NOT a major characteristic feature of biodiversity 'Hot Spot'?

Which one of the following statements does not improve the reproductive health of society?

Answer the question on the basis of passage given below :
Nitrogen differs from rest of the members of group 15 due to its small size, high electronegativity, high ionization enthalpy and non-availability of d orbitals. Nitrogen has unique ability to form pa - pa multiple bonds with itself and with other elements having small size and high electronegativity. Heavier elements of this group do not form pa - pr bonds as their atomic orbitals are so large and diffuse that they cannot have effective overlapping.
Arrange the following in decreasing order of their basic strength :
A. PH3 \(_3\)
B. \(AsH _3\)
C. \(NH _3\)
D. \(SbH _3\)
E. \(BiH _3\)
Choose the correct answer from the options given below:

Down's syndrome is a genetic disorder. It is due to:

The function \(f(x)=\sin 3 x, x \in\left[0, \frac{\pi}{2}\right]\)
(A) is increasing on \(\left[0, \frac{\pi}{6}\right]\)
(B) is decreasing on \(\left[\frac{\pi}{6}, \frac{\pi}{2}\right]\)
(C) is increasing on \(\left[0, \frac{\pi}{2}\right]\)
(D) is decreasing on \(\left[0, \frac{\pi}{2}\right]\)
Choose the correct answer from the options given below :

Arrange the following electromagnetic waves in the ascending order of their wavelengths.
(A) Radio waves
(B) Gamma rays
(C) Infrared rays
(D) Ultraviolet rays
Choose the correct answer from the options given below:

In Young's double slit experiment using monochromatic light of wavelength \(\lambda\) the intensity of light at a point on the screen is 20 units, where the path difference is \(\lambda\). The intensity of light at a point having the path difference \(\lambda / 4\) is

If A and B are two events such that \(P(B) = \frac{3}{5}\), \(P(A|B) = \frac{1}{2}\) and \(P(A \cup B) = \frac{4}{5}\), then P(A) is equal to: