Single answerDifficulty 3/5 · ChallengingOlympiadArgumentationRepresenting data
Mouse–human hybrid cells
A research group repeats the classic mouse–human cell fusion experiment of Frye and Edidin (1970). Mouse and human cells are fused into hybrid cells; mouse surface proteins are labelled with a green fluorescent antibody and human surface proteins with a red one. Right after fusion each hybrid is green on one half and red on the other. The group counts the percentage of hybrids in which the colours have fully intermixed.
Experimental setup
- Question
- How do proteins in the plasma membrane come to be intermixed?
- Independent variable
- Temperature and inhibitor treatment
- Dependent variable
- Percentage of hybrid cells with fully mixed colours
- Kept constant
- Same cell lines · Same antibodies · Same counting criteria
- Groups
- Control: 37 °C
- Cold: 10 °C
- ATP poison: 37 °C with inhibitors that drain cellular ATP
- No protein synthesis: 37 °C with an inhibitor of protein synthesis
- Cold then warm: 40 min at 10 °C, then 40 min at 37 °C
Data
| Treatment | 10 min (%) | 25 min (%) | 40 min (%) |
|---|---|---|---|
| 37 °C | 30 | 62 | 92 |
| 10 °C | 0 | 2 | 4 |
| 37 °C + ATP poison | 28 | 60 | 90 |
| 37 °C + protein-synthesis inhibitor | 31 | 61 | 91 |
| 10 °C for 40 min, then 37 °C | − | − | 88 (after the extra 40 min at 37 °C) |
Which explanation fits all of these results?
Answer every part to submit.