IB DP Biology- B2.3 Cell specialization - IB Style Questions For SL Paper 1A -FA 2025
▶️ Answer/Explanation
The earliest embryonic stem cells in mammals can produce every type of cell in the body, as well as extraembryonic structures such as the placenta. Cells with this complete developmental potential are described as totipotent.
✅ Answer: (A)
▶️ Answer/Explanation
Explanation:
All body cells in an organism contain the same DNA. However, different cell types express different sets of genes depending on their specialized functions. This process is called differential gene expression and allows a stem cell to differentiate into various specialized cells such as red blood cells and white blood cells. Although both contain identical genetic material, each activates specific genes to develop unique structures and functions.
Option Evaluation:
A. Incorrect – The number of mitotic divisions does not determine the type or function of a mature blood cell.
B. Correct – The difference between red and white blood cells is due to differential gene expression, even though they share the same DNA.
C. Incorrect – While red blood cells react to oxygen, this describes their function, not the cause of their structural differences.
D. Incorrect – White blood cells respond to antigens as part of their immune function, but this results from differentiation, not the reason they became white blood cells.