FMGE 2018 Practice Questions

Q: Most Common enzyme deficient in galactosemics:

Galactose-1-phosphate uridyl transferase/GALT. ***Galactose-1-phosphate uridyl transferase/GALT*** - **GALT deficiency** is the most common cause of **classic galactosemia** (Type I), a severe inherited metabolic disorder. - This enzyme is crucial for converting **galactose-1-phosphate** to **glucose-1-phosphate** in the main pathway of galactose metabolism. - Accounts for approximately **95%** of all galactosemia cases. *Galactosidase* - **Galactosidase** enzymes are involved in the hydrolysis of galactose-containing oligosaccharides or glycoconjugates but are not the primary enzymes deficient in classic galactosemia. - This enzyme is not part of the Leloir pathway of galactose metabolism, which is the pathway affected in galactosemia. *UDP galactose epimerase* - Deficiency of **UDP galactose epimerase** (GALE) causes a milder form of galactosemia (Type III), but it is much less common than GALT deficiency. - GALE is involved in the interconversion of UDP-galactose and UDP-glucose. - This is the rarest form of galactosemia. *Galactokinase* - **Galactokinase deficiency** (GALK) causes a different, milder form of galactosemia (Type II), characterized by **cataracts** as the primary symptom. - It prevents the initial phosphorylation of galactose to galactose-1-phosphate. - This accounts for less than 5% of galactosemia cases.

Q: Classical complement is activated by:

Ag-Ab complex. ***Ag-Ab complex*** - The **classical complement pathway** is initiated by the binding of **C1q** to an antigen-antibody complex, specifically involving **IgM** or certain subclasses of **IgG**. - This binding triggers a cascade of events leading to the activation of the complement system, ultimately resulting in the **lysis of target cells**, **opsonization**, and **inflammation**. *C3 Convertase* - **C3 convertase** is an enzyme complex formed later in the complement cascade, responsible for cleaving C3 into C3a and C3b. - While essential for all complement pathways, it is a **downstream effector** and not the initial activator of the classical pathway. *C1* - **C1** is a complex protein that includes C1q, C1r, and C1s. While C1 plays a crucial role in the classical pathway, it is **activated by** the antigen-antibody complex, not an independent activator. - The activation sequence is: **Ag-Ab complex → C1q binding → C1 activation → cascade initiation**. Thus, the Ag-Ab complex is the primary trigger, and C1 is the responder. *IgA* - **IgA** primarily functions in mucosal immunity and is generally **not an activator** of the classical complement pathway. - Instead, IgA can activate the **alternative complement pathway** under specific circumstances, but not the classical pathway through direct binding to C1q.

Q: In Plasmodium vivax malaria, relapse is caused by:

Hypnozoite. ***Hypnozoite*** - **Hypnozoites** are dormant forms of *Plasmodium vivax* and *P. ovale* that persist in the liver for months to years after initial infection. - These dormant hepatic stages can later reactivate, develop into merozoites, and cause a **relapse** of malaria symptoms even after successful treatment of the blood-stage infection. - Relapses are a defining feature of *P. vivax* malaria and require treatment with **primaquine** or **tafenoquine** for radical cure to eliminate hypnozoites. *Incorrect: Schizont* - **Schizonts** are stages where asexual reproduction occurs, either in liver cells (hepatic schizonts) or red blood cells (erythrocytic schizonts). - Erythrocytic schizonts cause acute malaria symptoms but do not cause delayed relapses as they are cleared by standard antimalarial treatments. - Hepatic schizonts complete their cycle within 1-2 weeks and do not remain dormant. *Incorrect: Sporozoite* - **Sporozoites** are the infective stage injected by the mosquito that travel to the liver to initiate infection. - They differentiate into either developing schizonts or dormant hypnozoites but do not directly cause relapses. - Sporozoites represent the initial infection, not the mechanism of relapse. *Incorrect: Gametocyte* - **Gametocytes** are the sexual stage found in human blood that are ingested by mosquitoes to continue the parasite lifecycle. - They are responsible for transmission to mosquitoes but do not cause human symptoms or relapses in the host. - Gametocytes do not remain dormant in the liver.

Q: Highest Contraceptive failure is reported in

Spermicidal methods. ***Spermicidal methods*** - **Spermicides** have a significantly higher failure rate compared to other contraceptive methods because their effectiveness relies heavily on **correct and consistent application** before each act of intercourse. - Their efficacy is often compromised by improper use, short duration of action, or failure to adequately kill sperm, leading to a higher chance of **unintended pregnancy**. *Implant* - Contraceptive **implants** (e.g., etonogestrel implant) are among the most effective contraceptive methods, with a very low failure rate due to **continuous hormone release**. - They offer **long-acting reversible contraception (LARC)**, eliminating user error upon insertion. *IUD* - **Intrauterine devices (IUDs)**, both hormonal and copper, are highly effective LARC methods with very low failure rates. - Their effectiveness is independent of user adherence after insertion, making them **highly reliable**. *Oral contraceptive pills* - **Oral contraceptive pills** are effective when used perfectly, but their typical use effectiveness is lower than implants or IUDs due to the possibility of **user error**, such as missing pills. - **Adherence** to a daily regimen is crucial for their efficacy.

Q: Most common site of osteomyelitis in children

Metaphysis. ***Metaphysis*** - The **metaphysis** is the most common site for osteomyelitis in children due to its rich, **slow-flowing sinusoidal blood supply**, which facilitates bacterial seeding. - The **nutrient arteries** in the metaphysis make sharp loops, creating a turbulent flow that slows circulation and allows bacteria to lodge more easily. *Epiphysis* - The **epiphysis** is less commonly affected in children because its separate blood supply is not as prone to bacterial seeding as the metaphysis. - In infants, however, infection can spread from the metaphysis to the epiphysis and joint space due to **transphyseal vessels**. *Growth plate* - The **growth plate** itself is generally resistant to infection due to its avascular nature. - However, infection in the adjacent metaphysis or epiphysis can potentially disrupt its function. *Diaphysis* - While the **diaphysis** has a blood supply, it is less common for osteomyelitis to originate here compared to the metaphysis. - It usually occurs as a secondary spread from a metaphyseal infection or in specific scenarios like in **sickle cell disease**.

Q: Marble bone disease is:

Osteopetrosis. ***Osteopetrosis*** - **Osteopetrosis**, also known as **marble bone disease**, is a rare genetic disorder characterized by abnormally dense bones due to a defect in **osteoclast function** [1]. - Impaired bone resorption leads to an accumulation of woven bone, causing bones to be fragile despite their density [1]. *Osteosclerosis* - **Osteosclerosis** is a general term for increased bone density and can be a feature of various conditions, including osteopetrosis. - However, it is a descriptive term rather than a specific disease diagnosis equivalent to marble bone disease. *Histiocytosis X* - **Histiocytosis X**, also known as **Langerhans cell histiocytosis**, is a rare disorder involving the proliferation of Langerhans cells. - It primarily affects bone but can also involve other organs, presenting with lytic lesions rather than increased bone density. *Osteomalacia* - **Osteomalacia** is a condition characterized by inadequate mineralization of bone tissue, leading to soft and weakened bones. - It is typically caused by **vitamin D deficiency** and is the opposite of increased bone density. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Bones, Joints, and Soft Tissue Tumors, pp. 1188-1189.

Q: Most common benign breast tumour:

Fibroadenoma. ***Fibroadenoma*** - **Fibroadenomas** are the **most common benign breast tumors**, typically presenting as mobile, firm, and non-tender masses [1]. - They are composed of both **glandular and stromal tissue** and are more prevalent in younger women [1]. *Phyllodes tumour* - **Phyllodes tumors** are much **rarer** than fibroadenomas and can be benign, borderline, or malignant [3]. - They tend to grow **rapidly** and are characterized by a leaf-like stromal pattern [3]. *Fibroadenosis* - **Fibroadenosis** (or fibrocystic changes) refers to a collection of **benign changes** in the breast tissue, including cysts, fibrosis, and epithelial hyperplasia, rather than a single tumor [2]. - It is a common condition causing lumpy and painful breasts, especially before menstruation [4]. *DCIS* - **Ductal Carcinoma In Situ (DCIS)** is a **non-invasive form of breast cancer** where abnormal cells are confined to the milk ducts. - It is not a benign tumor and carries a risk of progression to invasive breast cancer. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Liver And Biliary System Disease, pp. 448-449. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Liver And Biliary System Disease, pp. 445-446. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Breast, p. 1074. [4] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Breast, p. 1052.

Q: Pharmacodynamics deals with:-

Mechanism of action of a drug. Detailed study of the **Mechanism of action of a drug** [1][2] - **Pharmacodynamics** describes what the **drug does to the body**, including its **molecular targets** and biochemical effects [3]. - This involves the study of the drug's mechanisms to produce its therapeutic or toxic effects [2]. *Latency of onset* - **Latency of onset** refers to the time it takes for a drug to start producing its effects, which is a pharmacokinetic rather than a pharmacodynamic parameter. - It deals with the drug's absorption and distribution rather than its interaction with the body once it reaches its site of action. *Transport of drug across the biological membranes* - The **transport of drugs across biological membranes** is a key aspect of **pharmacokinetics**, specifically absorption and distribution [1]. - This process determines how much drug reaches its target site, not how it interacts with the target. *Mode of excretion of a drug* - The **mode of excretion** of a drug (e.g., renal, hepatic) falls under **pharmacokinetics**, addressing how the body gets rid of the drug. - This process influences the drug's duration of action and elimination half-life, not its mechanism of action.

Q: Cold water is not used for ear cleaning because

Caloric stimulation caused by cold water. ***Caloric stimulation caused by cold water*** - Irrigating the ear canal with **cold water** causes significant **caloric stimulation** of the vestibular system. - This can induce **vertigo**, **nausea**, and **vomiting** due to the temperature difference stimulating the semicircular canals. *Damage to tympanic membrane* - While excessive pressure from irrigation can potentially damage the **tympanic membrane**, the temperature of the water itself is not the primary factor for this risk. - Damage is more related to the **force of irrigation** and pre-existing membrane integrity, not cold temperature. *It will cause infection* - The temperature of the water used for irrigation does not directly determine the risk of infection. - **Infection risk** is primarily associated with using unsterile water or introducing bacteria into a compromised ear canal, regardless of water temperature. *It will make the wax hard* - Earwax, or **cerumen**, is softened by water irrigation, not hardened. - **Warm water** is typically preferred because it aids in softening the wax more effectively and comfortably than cold water.

Question 1

Most Common enzyme deficient in galactosemics:

Accepted Answer

Galactose-1-phosphate uridyl transferase/GALT

Answer

Galactosidase

Answer

UDP galactose epimerase

Answer

Galactokinase

Question 2

Chaperones are:

Accepted Answer

Mediators of post-translational assembly of protein complexes

Answer

Antigen presenting cells

Answer

Purine metabolism mediators

Answer

None of the above

Question 3

Classical complement is activated by:

Accepted Answer

Ag-Ab complex

Answer

C3 Convertase

Answer

C1

Answer

IgA

Question 4

In Plasmodium vivax malaria, relapse is caused by:

Accepted Answer

Hypnozoite

Answer

Schizont

Answer

Sporozoite

Answer

Gametocyte

Question 5

Highest Contraceptive failure is reported in

Accepted Answer

Spermicidal methods

Answer

Implant

Answer

IUD

Answer

Oral contraceptive pills

Question 6

Most common site of osteomyelitis in children

Accepted Answer

Metaphysis

Answer

Epiphysis

Answer

Growth plate

Answer

Diaphysis

Question 7

Marble bone disease is:

Accepted Answer

Osteopetrosis

Answer

Osteosclerosis

Answer

Histiocytosis X

Answer

Osteomalacia

Question 8

Most common benign breast tumour:

Accepted Answer

Fibroadenoma

Answer

Phyllodes tumour

Answer

Fibroadenosis

Answer

DCIS

Question 9

Pharmacodynamics deals with:-

Accepted Answer

Mechanism of action of a drug

Answer

Latency of onset

Answer

Transport of drug across the biological membranes

Answer

Mode of excretion of a drug

Question 10

Cold water is not used for ear cleaning because

Accepted Answer

Caloric stimulation caused by cold water

Answer

Damage to tympanic membrane

Answer

It will cause infection

Answer

It will make the wax hard

FMGE 2018

Biochemistry

Microbiology

Obstetrics and Gynecology

Orthopaedics

Pathology

Pharmacology

Physiology