Question

Mature erythrocytes are enucleated in following animals EXCEPT
i. Rat
ii. Monkey
iii. Llama
iv. Camel
v. Elephant
Choose the correct answer from options given below.

• A. i and ii only
• B. iii, iv and v only
• C. iii and iv only
• D. v only

Hint:

Remember: All mammals generally have enucleated RBCs. Questions may test rare or contextual exceptions—read carefully!

Answer 1

The Correct Option is D

Concept: In mammals, mature erythrocytes (red blood cells) are generally enucleated (lack a nucleus), which increases space for hemoglobin and enhances oxygen transport efficiency.
• Most mammals (rat, monkey, camel, llama) have enucleated RBCs.
• However, some exceptions exist in special cases or developmental stages.

Step 1: Understand enucleation.
Enucleation refers to the loss of nucleus during RBC maturation.

Step 2: Analyze given animals.
• Rat: Enucleated RBCs
• Monkey: Enucleated RBCs
• Llama: Enucleated RBCs
• Camel: Enucleated RBCs (oval shaped but no nucleus)
• Elephant: Exception considered in this context

Step 3: Conclusion.
Thus, elephant is the exception among the given options. Final Answer: Option (D)