UPSC-CMS 2023 - Physiology PYQs Practice Questions

Q: The removal of malarial parasites from the blood is called

Phagocytosis. ***Phagocytosis*** - **Phagocytosis** is the process by which specialized cells, such as **macrophages** and **neutrophils**, engulf and digest foreign particles, including malarial parasites in the blood. - This is a crucial immune mechanism for clearing infected red blood cells and free parasites from the body. - Phagocytosis occurs primarily in the **spleen, liver, and bone marrow**, where macrophages recognize and destroy parasitized RBCs. *Binding* - **Binding** refers to the initial attachment of parasites or infected cells to host cells or tissues. - While binding is a step in the parasitic lifecycle and influences sequestration, it is not the process of *removal* from the blood. *Culling* - **Culling** refers to the selective removal of damaged, aged, or parasitized red blood cells by the spleen. - In malaria, the spleen does "cull" infected RBCs through mechanical filtration and phagocytic clearance. - However, **phagocytosis** is the broader immunological term that describes the cellular mechanism of engulfment and destruction, making it the more appropriate general answer. *Sequestration* - **Sequestration** is the process by which malarial parasites (specifically *Plasmodium falciparum*) in infected red blood cells adhere to the endothelium of capillaries and venules, especially in vital organs. - This mechanism allows parasites to **avoid clearance** by the spleen, representing a process of *retention* or *hiding* rather than removal from the circulation. [Practice more Physiology PYQs on OnCourse]

Q: Stored blood which has been preserved in a blood bank is deficient in which of the following coagulation factors?

V and VIII. ***V and VIII*** - **Factors V and VIII** are **labile coagulation factors** that degrade quickly during blood storage, making them deficient in stored blood. - This lability is due to their protein structure, which is sensitive to breakdown at refrigerated temperatures over time. *IX and X* - **Factors IX and X** are relatively stable and **vitamin K-dependent factors** that maintain their activity well in stored blood. - They are not significantly depleted during standard blood bank storage periods. *II and VII* - **Factors II (prothrombin) and VII** are also **vitamin K-dependent factors** known for their stability in stored blood. - Their levels remain largely preserved for typical blood storage durations. *II only* - **Factor II (prothrombin)** is a **stable, vitamin K-dependent factor**, and its levels are well-preserved in stored blood. - Therefore, stating only factor II is deficient is incorrect, as it is one of the more stable factors. [Practice more Physiology PYQs on OnCourse]

Q: The respective hormones responsible for the breast milk secretion and ejection are, in that order:

Prolactin and Oxytocin. ***Prolactin and Oxytocin*** - **Prolactin** is the primary hormone responsible for the **synthesis and secretion of milk** from the mammary glands. - **Oxytocin** is responsible for the **milk ejection reflex**, causing contraction of myoepithelial cells around the alveoli and ducts to release milk. *Oestrogen and Prolactin* - **Oestrogen** primarily plays a crucial role in the **development of the mammary glands** during puberty and pregnancy, but it inhibits milk secretion. - While **prolactin** is involved in milk secretion, oestrogen's role is not milk ejection. *Oxytocin and Prolactin* - This option reverses the order of the hormones' functions; **oxytocin** is for ejection, not secretion first. - **Prolactin** is for milk secretion, not ejection. *Prolactin and Oestrogen* - **Prolactin** is responsible for milk secretion. - **Oestrogen** *inhibits* milk secretion and is not involved in milk ejection. [Practice more Physiology PYQs on OnCourse]

Q: The absence of fructose in the seminal fluid indicates a defect of

Seminal vesicles. ***Seminal vesicles*** - The **seminal vesicles** are responsible for producing and secreting a significant portion of the seminal fluid, including **fructose**. - **Fructose** serves as the primary **energy source** for sperm motility; its absence indicates a defect in these glands. *Leydig cells* - **Leydig cells** are located in the testes and primarily produce **testosterone**, which is crucial for male sexual development and spermatogenesis. - While important for sperm production indirectly, they do not directly contribute to the **fructose content** of seminal fluid. *Hypothalamic-pituitary axis* - The **hypothalamic-pituitary axis** regulates testicular function by releasing hormones like **GnRH**, **LH**, and **FSH**, which control testosterone production and spermatogenesis. - A defect here would primarily affect hormone levels and sperm production, not directly the **fructose secretion** from seminal vesicles. *Testicular tubular epithelium* - The **testicular tubular epithelium** (Sertoli cells and germ cells) is involved in **spermatogenesis**, the process of sperm formation. - While essential for producing mature sperm, it does not contribute to the production or secretion of **fructose** into the seminal fluid. [Practice more Physiology PYQs on OnCourse]

Q: The genetic inheritance of Haemophilia is

Sex-linked recessive. ***Sex-linked recessive*** - Hemophilia, specifically hemophilia A and B, is inherited in an **X-linked recessive** pattern. - Males, having only one X chromosome, are predominantly affected, as a single copy of the mutated gene on the X chromosome leads to the condition. *Autosomal recessive* - Autosomal recessive disorders require **two copies** of the mutated gene (one from each parent) to manifest, and affect males and females equally. - This inheritance pattern does not explain the male predominance and carrier status in females seen in hemophilia. *Autosomal dominant* - Autosomal dominant disorders require only **one copy** of the mutated gene to cause the disease, and also affect males and females equally. - This pattern would mean an affected parent has a 50% chance of passing the condition to each child, which is not characteristic of hemophilia. *Sex-linked dominant* - Sex-linked dominant disorders would affect both males and females, with affected fathers passing the trait to **all their daughters** but none of their sons. - This pattern is not consistent with the inheritance of hemophilia, where affected mothers can pass it to their sons. [Practice more Physiology PYQs on OnCourse]

Question 1

The removal of malarial parasites from the blood is called

Accepted Answer

Phagocytosis

Answer

Binding

Answer

Culling

Answer

Sequestration

Question 2

Stored blood which has been preserved in a blood bank is deficient in which of the following coagulation factors?

Accepted Answer

V and VIII

Answer

IX and X

Answer

II and VII

Answer

II only

Question 3

The respective hormones responsible for the breast milk secretion and ejection are, in that order:

Accepted Answer

Prolactin and Oxytocin

Answer

Oestrogen and Prolactin

Answer

Oxytocin and Prolactin

Answer

Prolactin and Oestrogen

Question 4

The absence of fructose in the seminal fluid indicates a defect of

Accepted Answer

Seminal vesicles

Answer

Leydig cells

Answer

Hypothalamic-pituitary axis

Answer

Testicular tubular epithelium

Question 5

The genetic inheritance of Haemophilia is

Accepted Answer

Sex-linked recessive

Answer

Autosomal recessive

Answer

Autosomal dominant

Answer

Sex-linked dominant

Question 6

The ratio for Type-I to Type-III collagen during maturation of collagen in remodelling phase is :

Accepted Answer

2 : 1

Answer

1 : 1

Answer

4 : 1

Answer

3 : 1

Question 7

Which of the following are the functions of larynx ?

1. Fixation of the chest
2. Aids in swallowing of food
3. Phonation
4. Respiration

Select the correct answer using the code given below :

Accepted Answer

All of the above (1, 2, 3 and 4)

Answer

1, 2 and 3

Answer

2, 3 and 4

Answer

1, 3 and 4

Question 8

Carbohydrate metabolism in normal pregnancy shows :

Accepted Answer

Fasting hypoglycaemia

Answer

Decreased plasma glucagon levels

Answer

Postprandial hypoglycaemia

Answer

Increased sensitivity of insulin receptors in mother

Question 9

Smoking is considered to be a modifiable risk factor for Coronary Heart Disease. Consider the following statements with regard to possible mechanisms on the basis of which it acts as a risk factor :

1. Nicotine stimulation of adrenergic drive raises the blood pressure and myocardial oxygen demand.
2. It increases carbon monoxide and induces atherogenesis.
3. It leads to fall in protective high density lipoproteins.
4. It reduces the apolipoprotein-B plasma levels. Which of the statements given above are correct ?

Accepted Answer

1, 2 and 3

Answer

2, 3 and 4

Answer

1 and 3 only

Answer

1 and 2 only

Question 10

With reference to human body's requirement for proteins, they are essential because they are:

1. an important alternative source for energy during specific metabolic states.
2. the primary molecules responsible for maintenance of osmotic pressure within the extracellular compartment.
3. critical for upkeep of cell mediated immune response.
4. vital for the synthesis of certain hormones.

Which of the statements given above are correct?

Accepted Answer

1, 3 and 4

Answer

2, 3 and 4

Answer

1, 2 and 3

Answer

1, 2 and 4

UPSC-CMS 2023 — Physiology