NEET-PG 2013 Practice Questions

Q: Which vitamin is required for transfer of 1-carbon unit?

Folic acid. ***Folic acid*** - **Folic acid** (vitamin B9) is essential for the transfer of **one-carbon units**, particularly as **tetrahydrofolate (THF)**. - These one-carbon units are critical in metabolic processes such as **DNA synthesis**, **amino acid metabolism**, and **neurotransmitter synthesis**. *Vitamin A* - **Vitamin A** (retinol) is primarily involved in **vision**, **immune function**, and **cell differentiation**. - It does not play a direct role in the transfer of one-carbon units. *Vitamin B12* - **Vitamin B12** (cobalamin) is involved in two main reactions: the conversion of **methylmalonyl-CoA to succinyl-CoA** and the transfer of a **methyl group from N5-methyl THF to homocysteine** to form methionine. - While it works with folate, it does not directly transfer one-carbon units in the same way as folic acid. *Niacin* - **Niacin** (vitamin B3) is a precursor to **NAD+ and NADP+**, which are crucial coenzymes in **redox reactions** and energy metabolism. - It is not involved in the transfer of one-carbon units.

Q: Which Millennium Development Goal specifically addresses HIV/AIDS?

Goal 6: Combat HIV/AIDS, malaria and other diseases. ***Goal 6: Combat HIV/AIDS, malaria and other diseases*** - This Millennium Development Goal (MDG) directly focused on reducing the spread of **HIV/AIDS**, malaria, and other major diseases as a key global health priority. - It included targets such as halting and beginning to reverse the incidence of HIV/AIDS, and achieving universal access to treatment for HIV/AIDS for all who need it. *Goal 1: Eradicate extreme poverty and hunger* - This goal addressed fundamental socioeconomic issues like **poverty** and **food insecurity**, which are broad determinants of health but not specific to HIV/AIDS. - While poverty can exacerbate the impact of HIV/AIDS, this MDG did not directly target the disease itself. *Goal 3: Promote gender equality and empower women* - This MDG focused on improving the status of women and girls, recognizing that **gender inequality** can be a risk factor for HIV transmission. - However, it did not directly address the combatting of HIV/AIDS as its primary objective. *Goal 8: Develop a global partnership for development* - This goal focused on improving international cooperation for development, including access to affordable **essential medicines**, which could include antiretrovirals for HIV/AIDS. - While it supported efforts to combat HIV/AIDS through partnerships, it was not solely dedicated to this health challenge.

Q: What term describes the patterns of inter-relationships between individuals in a society?

Social structure. ***Social structure*** - This term encompasses the **persistent, organized patterns** of relationships and institutions that shape social interaction within a society. - It refers to the underlying framework that dictates how individuals and groups are connected and positioned relative to each other. *Social relationships* - This refers to the **individual connections and interactions** between people, such as friendships, family ties, or professional collaborations. - While social relationships are components of social structure, they do not describe the overarching patterns of inter-relationships at a societal level. *Social networks* - This term describes the **specific web of social ties** that link individuals to one another, often visualized as nodes and connections. - While useful for mapping connections, it is a more specific concept than the broader idea of social structure, which includes institutional arrangements and roles. *Social systems* - This refers to a **set of interconnected social components** that function together to maintain order and stability within a society. - While social structure is a key aspect of a social system, the term "social system" itself is broader, encompassing the dynamic processes and functions alongside the established patterns.

Q: Which immunoglobulin is most efficient at fixing C1q in the classical complement pathway?

IgM. ***IgM*** - **IgM** is the most efficient immunoglobulin at activating the **classical complement pathway** due to its pentameric structure, which provides multiple binding sites for C1q. - The **Fc portion** of IgM, when bound to an antigen, undergoes a conformational change that exposes binding sites for the **C1q component** of complement. *IgA* - **IgA** primarily functions in **mucosal immunity** and does not efficiently activate the classical complement pathway. - It can weakly activate the **alternative complement pathway** but is not known for fixing C1. *IgG* - **IgG** can activate the classical complement pathway, but it requires two or more IgG molecules to be in close proximity on the cell surface to effectively bind C1q, making it less efficient than IgM. - Its **Fc region** binds C1q only when **antigen-antibody complexes** are formed, but it's not the primary immunoglobulin for initiating C1 binding in solitary form. *IgE* - **IgE** is primarily involved in **allergic reactions** and defense against parasites, binding to Fc receptors on mast cells and basophils. - It does **not activate the complement system** via the classical pathway and therefore does not fix C1.

Q: Thumb print appearance in a culture film smear is seen in which of the following organisms?

Bacillus anthracis. ***Bacillus anthracis*** - The "**thumb print**" or "**boxcar**" appearance refers to the characteristic microscopic morphology seen in **Gram-stained smears** of *B. anthracis*. - The bacilli appear as large, rectangular, Gram-positive rods with **square ends** (resembling boxcars), often arranged in chains. - This distinctive appearance aids in the laboratory diagnosis of **anthrax**. - On culture plates, colonies show a "**Medusa head**" appearance with irregular edges. *Bordetella pertussis* - Colonies on **Bordet-Gengou agar** exhibit a "**mercury drop**" or "**pearl-like**" appearance—smooth, glistening, dome-shaped colonies. - This is different from the "thumb print" morphology, which refers to microscopic rather than colonial appearance. - *B. pertussis* is the causative agent of **whooping cough** (pertussis). *Brucella species* - Produce small, smooth, translucent, slightly raised colonies on enriched media. - Lack any distinctive "thumb print" morphology in smears. - Causative agents of **brucellosis** (undulant fever), a zoonotic infection. *Clostridium perfringens* - Large, Gram-positive rods that may appear boxcar-shaped but are typically associated with **double zone of hemolysis** on blood agar. - Colonies are large, flat, and spreading, not exhibiting the classical "thumb print" identification feature. - Common cause of **gas gangrene** and food poisoning.

Q: All of the following are postcoital contraception methods except?

Barrier methods. ***Barrier methods*** - **Barrier methods** like condoms or diaphragms are used *during* intercourse to prevent pregnancy and STIs. - They are not a form of **postcoital contraception** as they do not act *after* unprotected sex has occurred. *Mifepristone* - **Mifepristone** can be used as an **emergency contraceptive** by delaying or inhibiting ovulation, or by altering the endometrium to prevent implantation. - It works *after* unprotected intercourse and is an effective form of **postcoital contraception**. *IUD* - The **copper intrauterine device (IUD)** can be inserted as an **emergency contraceptive** up to 5 days after unprotected intercourse. - It prevents pregnancy primarily by creating a **spermicidal inflammatory reaction** in the uterus, making it unsuitable for implantation. *Levonorgestrel* - **Levonorgestrel-only pills** are a common form of **emergency contraception**, sometimes known as the "morning-after" pill. - They work by **delaying or inhibiting ovulation** and are effective when taken *within 72 hours* of unprotected sex.

Q: During angiogenesis, what factors are responsible for the recruitment of pericytes and periendothelial cells?

Angiopoietins, TGF & PDGF. ***Angiopoietins, TGF & PDGF*** - **Angiopoietins** are crucial for the stabilization of blood vessels and recruitment of **pericytes**, enhancing vessel maturation [1]. - **TGF (Transforming Growth Factor)** and **PDGF (Platelet-Derived Growth Factor)** also play significant roles in the recruitment and proliferation of **pericytes** and periendothelial cells during angiogenesis [1]. *VEGF & PDGF* - While **VEGF (Vascular Endothelial Growth Factor)** is important for endothelial cell migration and proliferation, it does not directly recruit **pericytes** alone. - This combination lacks **angiopoietins**, which are key for the stabilization of newly formed blood vessels [1]. *VEGF, IL-2, IL-6* - **IL-2** and **IL-6** are primarily associated with immune responses and do not directly contribute to pericyte recruitment during angiogenesis. - **VEGF** alone supports endothelial cells but does not effectively recruit **pericytes** without the cooperation of other factors. *TGF, VEGF & PDGF* - Although both **TGF** and **PDGF** are involved in pericyte recruitment [1], the absence of **angiopoietins** limits the effectiveness of this combination for the recruitment process. - **VEGF** alone does not facilitate direct recruitment of **pericytes**, as it mainly focuses on endothelial cells. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, pp. 115-116.

Q: Heart failure cells are

Pigmented alveolar macrophages. ***Pigmented alveolar macrophages*** - These macrophages engulf **hemosiderin** (iron-rich pigment from degraded red blood cells) that leaks into the alveoli due to increased capillary pressure in left-sided **heart failure**. - The presence of **hemosiderin-laden macrophages** in the sputum or lung tissue is diagnostic for chronic pulmonary congestion caused by heart failure. *Lipofuscin granules in cardiac cells* - **Lipofuscin** is a "wear-and-tear" pigment that accumulates in aging cells, including cardiac cells. - While present in older hearts, its presence does not specifically indicate **heart failure** or represent "heart failure cells" in the described context. *Pigmented pancreatic acinar cells* - Pancreatic acinar cells primarily produce digestive enzymes and are not typically associated with **pigment accumulation** in the context of heart failure. - Pigmentation in pancreatic cells would suggest other pathologies, such as **hemochromatosis** affecting the pancreas. *Pigment cells seen in liver* - The liver can accumulate various pigments, such as **hemosiderin** in hemochromatosis or **bilirubin** in cholestasis. - While liver congestion can occur in right-sided heart failure, the specific "heart failure cells" refer to the **pulmonary macrophages**.

Q: Which of the following cancers is associated with osteolytic metastases?

All of the options. ***All of the options*** - **Lung**, **kidney**, and **thyroid** cancers are all known to frequently produce **osteolytic bone metastases** [1]. - These cancers release factors that stimulate **osteoclast activity**, leading to bone destruction rather than new bone formation. *Lung* - **Non-small cell lung cancer** often metastasizes to bone and commonly causes **osteolytic lesions** [2]. - Bone metastases are a frequent complication, particularly in advanced stages, and are associated with **pain** and **pathological fractures**. *Kidney* - **Renal cell carcinoma** is notorious for causing highly vascularized and often **osteolytic metastases** in bone [1]. - These lesions can be aggressive, leading to significant **bone destruction** and **hypercalcemia**. *Thyroid* - **Follicular thyroid carcinoma** and, less commonly, **papillary thyroid carcinoma** are known to cause **osteolytic bone metastases** [1]. - Thyroid cancer metastases in bone can be slow-growing but are typically **destructive** and may cause **pain** or **fractures**. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Osteoarticular And Connective Tissue Disease, pp. 671-672. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Lung, pp. 724-725.

Q: Among which of the following conditions is suicide risk highest?

Depression. ***Depression*** - **Major depressive disorder** is the psychiatric condition most frequently associated with **suicide**, accounting for a large percentage of completed suicides. - The presence of severe depression, especially with features like **hopelessness**, **agitation**, and **prior suicide attempts**, significantly elevate the risk. *Alcohol dependence* - While **alcohol dependence** is a significant risk factor for suicide, it often co-occurs with mood disorders like depression; alcohol can exacerbate suicidal ideation and impulsivity. - It is an important comorbidity, but **major depression** alone has a higher prevalence in suicide statistics than alcohol dependence as a primary factor. *Dementia* - **Dementia** generally poses a lower risk of completed suicide compared to mood disorders, as cognitive decline can impair the ability to plan and execute such acts. - Early stages of dementia, particularly when insight into cognitive decline is preserved, may carry some risk, but it is not the highest risk condition overall. *Schizophrenia* - Individuals with **schizophrenia** have a significantly elevated risk of suicide compared to the general population, often due to factors like **command hallucinations**, hopelessness, and adverse effects of medication. - However, **depression** remains the leading psychiatric diagnosis associated with suicide completions.

Question 1

Which vitamin is required for transfer of 1-carbon unit?

Accepted Answer

Folic acid

Answer

Niacin

Answer

Vitamin B12

Answer

Vitamin A

Question 2

Which Millennium Development Goal specifically addresses HIV/AIDS?

Accepted Answer

Goal 6: Combat HIV/AIDS, malaria and other diseases

Answer

Goal 1: Eradicate extreme poverty and hunger

Answer

Goal 3: Promote gender equality and empower women

Answer

Goal 8: Develop a global partnership for development

Question 3

What term describes the patterns of inter-relationships between individuals in a society?

Accepted Answer

Social structure

Answer

Social relationships

Answer

Social networks

Answer

Social systems

Question 4

Which immunoglobulin is most efficient at fixing C1q in the classical complement pathway?

Accepted Answer

IgM

Answer

IgA

Answer

IgG

Answer

IgE

Question 5

Thumb print appearance in a culture film smear is seen in which of the following organisms?

Accepted Answer

Bacillus anthracis

Answer

Brucella species

Answer

Bordetella pertussis

Answer

Clostridium perfringens

Question 6

All of the following are postcoital contraception methods except?

Accepted Answer

Barrier methods

Answer

IUD

Answer

Levonorgestrel

Answer

Mifepristone

Question 7

During angiogenesis, what factors are responsible for the recruitment of pericytes and periendothelial cells?

Accepted Answer

Angiopoietins, TGF & PDGF

Answer

VEGF & PDGF

Answer

VEGF, IL-2, IL-6

Answer

TGF, VEGF & PDGF

Question 8

Heart failure cells are

Accepted Answer

Pigmented alveolar macrophages

Answer

Lipofuscin granules in cardiac cells

Answer

Pigmented pancreatic acinar cells

Answer

Pigment cells seen in liver

Question 9

Which of the following cancers is associated with osteolytic metastases?

Accepted Answer

All of the options

Answer

Lung

Answer

Kidney

Answer

Thyroid

Question 10

Among which of the following conditions is suicide risk highest?

Accepted Answer

Depression

Answer

Alcohol dependence

Answer

Dementia

Answer

Schizophrenia

NEET-PG 2013

Biochemistry

Community Medicine

Microbiology

Obstetrics and Gynecology

Pathology

Psychiatry