Two steroid hormone receptors X and Y both contain a ligand-binding domain and a DNA binding domain. Using recombinant DNA technology, a modified hybrid receptor H is prepared such that it contains the ligand-binding domain of X and DNA binding domain of Y. Three sets of cells over-expressing receptors X, Y, and H were then treated separately either with hormone X or hormone Y. Assuming that there is no cross-reactivity, which one of the following graphs best represents the receptor-ligand binding in each case?

In animals, four separate families of cell-cell adhesion proteins are listed in Column A and their functional characteristics are given in Column B.

A	B
a. Integrin	(i) Lectins that mediate a variety of transient, cell-cell adhesion interactions in the blood stream.
b. Cadherin	(ii) Contains extracellular Ig-like domains and are mainly involved in the fine tuning of cell-cell adhesive interactions during development and regenration.
c. Ig-Super family	(iii) Mediates Ca2+-dependent strong homophilic cell-cell adhesion.
d. Selectin	(iv) Transmembrane cell adhesion proteins that act as extracellular matrix receptors.

Which one of the following is the correct combination?

• a - (i); b - (ii); c - (iii); d - (iv)

• a - (ii); b - (iii); c - (iv); d - (i)

• a - (iii); b - (iv); c - (i); d - (ii)

• a - (iv); b - (iii); c - (ii); d - (i)

A student treated cancer cells with an anti-cancer drug and performed western blot analysis. Which one of the following blots is the best representation of untreated control (C) and treated (T) samples?

Which one of the following statements regarding B cell receptor (BCR) and T cell receptor (TCR) is not true?

• TCR is membrane-bound and does not appear as soluble form as does the BCR.

• Unlike BCR, most of the TCR are not specific for antigen alone but for antigen combined with MHC.

• In order to activate signal transduction, BCR associates itself with Ig-α/ Ig-β whereas TCR associates with CD3.

• The antigen binding interactions of BCR is much weaker than TCR.

Which one of the following is NOT a bacterial disease?

• Tuberculosis

• Typhoid

• Tetanus

• Small pox

136.

The second messenger, which opens calcium ion pores in endoplasmic reticulum and plasma membrane is

• Diacylglycerol

• cAMP

• Phosphatidylinositol biphosphate

• Inositol triphosphate

Which one of the following cells generally does NOT secrete IFN-γ?

• CD8⁺ T cells

• TH1 cells

• NK cells

• TH2 cells 

The ability of cells to achieve their respective fates by interacting with other cells is known as

• autonomous specification

• conditional specification

• induction

• competence

In Schizosaccharomyces pombe, the recessive (cdc2r) and dominant (cdc2^D) mutants have opposing phenotypes. While cdc2^Dproduces abnormally small cells, cdc2^r produces abnormally long cells. Some possible explanations are given below:

A. cdc2^D may lack interaction with WEE1.

B. cdc2^r may not interact with CDC13 kinase.

C. cdc2^D may not interact with CDC25 phosphatase.

D. cdc2^r cells may be deficient in interaction with either CDC25 or WEE1.

Which combination of the above statements is correct?

• A and B only

• A, C, and D only

• B and C only

• A, B, and C only

Following are some statements about the mechanism of stimulation of receptors for touch, pain, vision, and warmth that may or may not be correct.

A. the touch receptor does not require any voltage-gated cation channel for its activation.

B. Light causes closing of Na⁺ channels in the outer segments of rods and cones.

C. Pain sensation is caused by opening of Na⁺ or Na⁺/ Ca⁺⁺ channels in free sensory nerve endings.

D. The warmth receptor is activated by non-selective anion channels.

Choose the option with both the statements as correct.

• A and C

• B and C

• C and D

• A and D