BIOCHEMISTRY, BIOMEDICINE & PHARMACEUTICS

Multiple Choice Questions on Antigen Processing and Presentation 1) The cells that display peptides associated with class II MHC molecules to CD4+ Th cells are called antigen presentation cells.  Which of the following is not a professional antigen-presenting cells? a) Dendritic cells b) Macrophages c) B cells d) Fibroblast 2) The professional antigen-presenting cells have different antigen uptake, constitutive MHC expression, and co-stimulatory activity.  Which of the following statement is true ? a) Dendritic cells constitutively express a high level of class II MHC molecules and co-stimulatory activity, they can activate naïve T cells. b) Macrophage must be activated by phagocytosis of particular antigens before they express class II MHC molecules or co-stimulatory B-47 membrane molecules c) B cells constitutively express class II MHC molecules but must be activated before they express the co-stimulatory signal d) All of the Above 3) The antigenic peptide...

                            MCQs on Immediate and Delayed Hypersensitivity Immediate and delayed hypersensitivity reactions are two distinct immune responses that occur in response to specific triggers, such as allergens or antigens. Immediate hypersensitivity, also known as Type I hypersensitivity, results in an immediate and rapid reaction upon exposure to the trigger. This type of hypersensitivity involves the release of histamine and other mediators, leading to symptoms like itching, swelling, and wheezing. It is crucial to identify and avoid allergens that trigger immediate hypersensitivity reactions to manage symptoms effectively. Delayed hypersensitivity, on the other hand, is characterized by a delayed onset, typically occurring within 24 to 72 hours after exposure. This type of hypersensitivity involves the activation of T cells and the release of cytokines, leading to inflammation and tissue damage. Delay...

Multiple Choice Question on Mumps, Measles, and Rubella viruses. MMR vaccine 1) Paramyxoviruses consists all of the following properties, EXCEPT? a) Consists of a segmented genome b) Envelope contains glycoprotein which has fusion activity c) Have negative RNA genome d) Replicate in the cytoplasm 2)  Each of the following pathogens can cause respiratory infections in humans, EXCEPT ? a) Respiratory syncytial virus b) Parainfluenza virus c) Measles virus d) Rabies virus 3) Respiratory syncytial virus primarily infects the lower respiratory tract of the lungs, it can cause bronchiolitis, and pneumonia in children and elderly people.  Which of the following virus is not a common pathogen found in lower respiratory tract infections? a) Rhinovirus b) Metapneumovirus c) Influenza virus d) Respiratory syncytial virus 4) Which of the following is an example of the natural hosts of the Mumps virus? a) Pigs b) Bats c) Horses d) Humans 5) Meas...

Multiple Choice of Questions on Mycoplasma species 1) Which of the following are the common human infections caused by Mycoplasma spp ?  Select the correct answers from the options given below a) Pneumonia b) Food poisoning c) Urethritis d) Skin infections 2) All of the following are the cultural characteristics of Mycoplasma spp , EXCEPT? a) They usually grow well in anaerobic or microaerophilic conditions b) They appear as large in size in culture media c) The cultures grow relatively slowly compared to other bacteria d) The colonies resemble fried egg in shape in the media  3) A 14-year-old boy develops a cough and fever after being exposed to a classmate with similar symptoms. Gram stain and culture tests confirm  Mycoplasma pneumoniae.  Which of the following is the commonly used antibiotic for the treatment of infection caused by M. pneumoniae ? a) Rifampin b) Sulfonamides c) Tetracyclines d) Vancomycin 4) Which of the followi...

T cell receptors (TCRs) are cell surface proteins expressed on the surface of T cells, a type of white blood cell involved in immune responses. TCRs play a crucial role in recognizing and binding to antigens, which are foreign substances that activate the immune system. The structure of TCRs consists of two protein chains, known as alpha (α) and beta (β) chains, which are linked together and form a heterodimer. Each TCR has a unique combination of α and β chains that determine its antigen specificity. The diversity of TCRs is generated through genetic recombination during T cell development, allowing T cells to recognize a wide range of antigens. When a TCR encounters an antigen presented on the surface of an antigen-presenting cell (APC), such as a dendritic cell or macrophage, it binds to the antigen with high specificity. This binding interaction between the TCR and antigen is critical for initiating an immune response. The TCR signaling cascade is then activated, leading to T ce...

Multiple Choice Question on MCQ on Subcutaneous Mycoses 1) A 35-year-old man residing in Mexico comes to the hospital with an ulcerative lesion on his left thumb and has been suffering for 2 weeks. He got a cut while taking care of the plants in his garden, in the first week the lesion did not grow or spread but it extended to the forearm and pain increased in the second week. A sample was taken from the infected site and was cultured for fungal examination, cream-colored colony appeared within 3 days. The colony appeared brown after few days and  after a week of incubation it transformed  into a black and fuzzy appearance. Which of the following is the likely pathogen ? a) Epidermophyton flocussum b) Tinea versicolor c) Sporothrix schenckii  d) Basidiobolus ranarum 2) Which of the following are NOT the cultural characteristics of fungus causing subcutaneous mycoses? a) Classification Includes dimorphic fungi b) The infections are caused by saprophytic ...

Influenza Virus & Subtypes (Flu virus) Type A, B, & C Multiple Choice Questions 1) Identify the False statement about the influenza viruses subtypes A , B , and C:  a) Influenza type A may be found in chickens, pigs, and horses b) Antigenic shifts or viral genome reassortment occurs in Influenza A virus c) All three types of viruses are found in humans and other animals d) Influenza virus infects mainly the upper respiratory tract 2)The properties of Orthomyxoviridae include all of the following statements, EXCEPT: a) The virus consists of single-stranded RNA b) The outer envelope of the virus is made up of lipid bilayer c) The size of the virus (150nm) is larger than the Paramyxoviruses   d) The hemagglutinin and neuraminidase of the influenza virus helps it to attach to the host cells 3) Which of the following are NOT the common symptoms of flu caused by the influenza virus in adults? a) Fever b) Cough c) Rashes d) Headache 4) Which o...