Compared to those of humans, the erythrocytes in frog are :

Question

Accepted Answer

C. 1. **Erythrocytes** (red blood cells) differ structurally between frogs and humans, so we compare their key features.

2. In frogs, erythrocytes are **large, oval, and biconvex**, and importantly, they **retain their nucleus**, unlike mature human red blood cells, which lose their nucleus during development.

3. Despite being nucleated, frog erythrocytes still contain the respiratory pigment **haemoglobin** in their cytoplasm, which is essential for carrying oxygen.

4. This rules out options suggesting the cells lack a nucleus or lack haemoglobin, since frog RBCs have **both** a nucleus and haemoglobin.

5. Since option C correctly describes frog erythrocytes as nucleated and containing haemoglobin, it is the correct answer.

Hence, the answer is **C (Nucleated and with haemoglobin)**.