Question 1
Multiple choiceMedium1 markA researcher measures cell adhesion and cell recognition before and after selectively removing carbohydrate chains from glycoproteins and glycolipids on the extracellular surface of the plasma membrane. The results are shown.
| Cell condition | Cells adhering to other cells (%) | Cells correctly recognized (%) |
|---|---|---|
| Untreated | 82 | 91 |
| Carbohydrate chains removed | 46 | 52 |
What conclusion is supported by the results?
Show answer and explanation
Answer: A. Removing the extracellular carbohydrate chains lowered adhesion from 82% to 46% and correct recognition from 91% to 52%. The paired decreases support a role for these structures in both processes.
B: accounts for the decrease in recognition but overlooks the decrease in adhesion.
C: accounts for the decrease in adhesion but overlooks the decrease in recognition.
D: reverses the relationship: removal decreased both responses, rather than increasing them.
Remember: membrane carbohydrate chains can contribute to cell adhesion and cell recognition.