General Pathology Practice Questions

Q: Enzymatic degradation of chromatin by endonucleases is referred to as:

Karyolysis. ### Explanation The hallmark of irreversible cell injury and cell death is nuclear change [1]. These changes occur in a sequential or distinct manner depending on the type of necrosis. **Why Karyolysis is Correct:** **Karyolysis** refers to the fading of the basophilia of chromatin. This process is driven by the **enzymatic degradation of DNA by endonucleases** (specifically DNase) released from lysosomes. As the DNA is hydrolyzed, the nucleus loses its staining intensity and eventually disappears completely within 1 to 2 days. **Analysis of Incorrect Options:** * **B. Pyknosis:** This is characterized by **nuclear shrinkage** and increased basophilia. The DNA condenses into a solid, shrunken, dark mass. It is the first stage of nuclear morphology changes in cell death [1]. * **C. Karyorrhexis:** This follows pyknosis. The pyknotic nucleus undergoes **fragmentation** (rupture of the nuclear membrane), breaking into multiple small, dense "nuclear dust" particles [1]. **High-Yield NEET-PG Pearls:** * **Sequence of Nuclear Changes:** Pyknosis (Condensation) → Karyorrhexis (Fragmentation) → Karyolysis (Dissolution). * **Apoptosis vs. Necrosis:** While karyolysis is a classic feature of **necrosis**, the characteristic nuclear change in **apoptosis** is internucleosomal DNA fragmentation (forming a "ladder" pattern on electrophoresis), but the nucleus typically fragments into membrane-bound apoptotic bodies without complete enzymatic dissolution (karyolysis) in the same manner. * **Basophilia:** Loss of basophilia in karyolysis is due to the loss of DNA, which is the acidic component that binds basic dyes like Hematoxylin. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Cellular Responses to Stress and Toxic Insults: Adaptation, Injury, and Death, p. 53.

Question 1

Hemolytic disease of the newborn is an example of which type of hypersensitivity reaction?

Accepted Answer

Type II hypersensitivity

Answer

Type III hypersensitivity

Answer

Arthus reaction

Answer

Type IV hypersensitivity

Question 2

In diseases, cell death of growth hormone cells occurs by which mechanism?

Accepted Answer

Apoptosis

Answer

Aging

Answer

Necrosis

Answer

All of the above

Question 3

Myotonic dystrophy is due to which genetic abnormality?

Accepted Answer

CTG trinucleotide repeat mutation

Answer

Expansion in a coding region

Answer

CAG trinucleotide repeat mutation

Answer

Mutation involving chromosome 15

Question 4

Which of the following diseases is transmitted as an X-linked inheritance?

Accepted Answer

Alport syndrome

Answer

Phenylketonuria

Answer

Myotonic dystrophy

Answer

Spinal muscular atrophy

Question 5

Enzymatic degradation of chromatin by endonucleases is referred to as:

Accepted Answer

Karyolysis

Answer

Pyknosis

Answer

Karyorrhexis

Answer

None of the above

Question 6

Russell bodies are typically seen in which of the following cell types?

Accepted Answer

Plasma cells

Answer

Lymphocytes

Answer

Neutrophils

Answer

Macrophages

Question 7

Which of the following conditions does not exhibit an X-linked pattern of inheritance?

Accepted Answer

Myotonic dystrophy

Answer

Duchenne muscular dystrophy

Answer

Emery-Dreifuss muscular dystrophy

Answer

Becker muscular dystrophy

Question 8

Pinpoint hemorrhages of less than 1 cm in diameter are known as?

Accepted Answer

Petechiae

Answer

Ecchymoses

Answer

Purpura

Answer

Pustules

Question 9

Autopsy of the spleen of a patient with portal hypertension shows Gamna-Gandy bodies. These bodies are characterized by the presence of hemosiderin and which of the following?

Accepted Answer

Calcium ions (Ca++)

Answer

Sodium ions (Na+)

Answer

Magnesium ions (Mg++)

Answer

Calcium (Ca)

Question 10

Respiratory burst is due to which enzyme?

Accepted Answer

NADPH oxidase

Answer

Catalase

Answer

SOD

Answer

Glutathione peroxidase

General Pathology — MCQs

General Pathology — MCQs

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