Author: Neelam Maurya

A. HPV

B. CMV

C. Molluscum contagiosum

D. BK polyoma

1. Owl’s eye

2. Henderson–Patterson bodies

3. Decoy cell

4. Koilocytes 

B. a-4,b-1,c -3,d-4

C. a-4,b-1,c-2,d-3

D. a-4,b-2,c-1,d-3

Correct Answer » C Explanation

Ans: C. a-4,b-1,c-2,d-3
* Koilocytes, also known as halo cells, are a type of epithelial cell that develops following a human papillomavirus (HPV) infection. Koilocytes are structurally different from other epithelial cells. For instance, their nuclei, which contain the cell’s DNA, are an irregular size, shape, or color.
* Owl’s eye appearance of inclusion bodies, which is highly specific for cytomegalovirus infection. Owl’s eye appearance of entire nucleus – a finding in Reed–Sternberg cells in individuals with Hodgkin’s lymphoma.
* Molluscum bodies, also called Henderson–Patterson bodies, are large, round cytoplasmic inclusions (within the enlarged cells of epidermis), which push the nucleus to the periphery.
* In BK Virus Infection condition the urinary sediment contains variable numbers of decoy cells sufficient to diagnose reactivation of the viral infection

A. Neuroblastoma

B. Retinoblastoma

C. Ewing’s sarcoma

D. Hemangiosarcoma

Correct Answer » D Explanation

Ans. is ‘d’ i.e., hemangiosarcoma

Small round blue cell tumors:

* Histologically many of the malignant paediatric neoplasms are unique.
* They tend to have a more primitive (embryonal) rather than pleomorphic anaplastic microscopic appearance.
* Often characterized by sheets of cells with small round nuclei.
* Frequently exhibit features of organogenesis specific to the site of tumour origin (therefore these tumours are frequently designated by suffix – blastoma).
* Owing to their primitive histological appearance many childhood tumours have been collectively referred to as small round blue cell tumour

The differential diagnosis of small round blue cell tumours includes

A. Mucin

B. Immunoglobulin

C. Ovalbumin

D. None of these

Correct Answer » A Explanation

Answer- A. Mucin

* glycoproteins found in the body is mucins, which are secreted in the mucus of the respiratory and digestive tracts. The sugars when attached to mucins give them considerable water-holding capacity and also make them resistant to proteolysis by digestive enzymes.

* O-Linked Glycans: • Mucins, which are found extensively in salivary secretions, contain many short O-linked glycans. • Increase the viscosity of the fluids 

A. Capping

B. Poly-A tail

C. tRNA

D. Shine-Dalgarno sequence

Correct Answer » A Explanation

Answer- A. Capping

* In E. coli mRNA, a leader sequence upstream of the first AUG codon, called the Shine-Dalgarno sequence (also known as the ribosomal binding site AGGAGG), interacts through complementary base pairing with the rRNA molecules that compose the ribosome.

* In eukaryotic initiation complex recognizes the 5′ cap of the eukaryotic mRNA, then tracks along the mRNA in the 5′ to 3′ direction until the AUG start codon is recognized. At this point, the 60S subunit binds to the complex of Met-tRNAi, mRNA, and the 40S subunit.

A. EGFR

B. CD23

C. IL6

D. IL2RG

Correct Answer » D Explanation

Answer-D. IL2RG

* X-linked severe combined immunodeficiency (SCID) is an inherited disorder of the immune system that occurs almost exclusively in males.

* Mutations in the IL2RG gene cause X-linked SCID. The IL2RG gene provides instructions for making a protein that is critical for normal immune system function.

* Mutations in the IL2RG gene prevent these cells from developing and functioning normally. Without functional lymphocytes, the body is unable to fight off infections.

A. Glutamine to Asparagine

B. Aspartate and Glutamate

C. Alanine to tryptophan

D. None of these

Correct Answer » A Explanation

Answer- A. Glutamine to Asparagine

* Glutamine and Asparagine are Amide group containing amino acids.

* These belongs to same category (hydrophilic /Homophilic) so no alteration in function

A. Histidine

B. Cysteine

C. Tyrosine

D. Arginine

Correct Answer » A Explanation

Answer-A- Histidine

Maximum buffering capacity occurs at a pH equal to the pKa,

 So amino acid which has pKa range near physiologic pH can act as an effective buffer

 * lmidazole group of histidine  – 6.5- 7.4 pKa range

 * SH group of cysteine→ 8.5-9.0 pKa range

 * OH group of tyrosine → 9.5-10.5 pKa range

*  Arginine → > 12

A. consist of a core protein with GAG chains attached.

B. GAG contain oxidized acid sugars

C. negative charges cause to radiate out from the protein

D. All of these

Correct Answer » D Explanation

Ans-D. All of these

* Proteoglycans contain many long unbranched polysaccharide chains attached to a core protein.

* The polysaccharide chains, called glycosaminoglycans, are composed of repeating disaccharide units containing oxidized acid sugars (such as glucuronic acid), sulfated sugars, and N-acetylated amino sugars.

* The large number of negative charges causes the glycosaminoglycan chains to radiate out from the protein so that the overall structure resembles a bottlebrush.

The proteoglycans are essential parts of the extracellular matrix, the aqueous humor of the eye, secretions of mucus-producing cells, and cartilage.