Which of the following is true about mature cysts of E. histolytica –
**Core Concept**
Mature cysts of Entamoeba histolytica are a crucial aspect of the parasite's life cycle, representing a resting stage that allows the organism to survive outside the host. The cysts are resistant to environmental stressors and can be transmitted through contaminated food or water.
**Why the Correct Answer is Right**
Mature cysts of E. histolytica contain four nuclei, which are arranged in a characteristic tetrad pattern. This feature is essential for their identification under a microscope. The cysts are formed when the parasite ingests red blood cells, which are then converted into a protein called hemoglobin. This process involves the action of several enzymes, including catalase, which helps to protect the cyst from oxidative stress.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is likely incorrect, as mature cysts of E. histolytica typically do not have a single nucleus. The presence of a single nucleus would be more characteristic of the trophozoite stage of the parasite.
**Option B:** This option is likely incorrect, as mature cysts of E. histolytica do not typically have a large number of vacuoles. While vacuoles may be present in some stages of the parasite's life cycle, they are not a defining feature of mature cysts.
**Option C:** This option is likely incorrect, as mature cysts of E. histolytica do not typically have a large number of flagella. Flagella are more characteristic of the trophozoite stage of the parasite.
**Clinical Pearl / High-Yield Fact**
It's essential to note that mature cysts of E. histolytica can be transmitted through contaminated food or water, emphasizing the importance of proper hygiene and sanitation practices in preventing the spread of this infection.
**Correct Answer:** C. Mature cysts of E. histolytica contain four nuclei, arranged in a characteristic tetrad pattern.