Only 1- the experiment can not show a cause and effect relationship if there are more than one factors contributing to the outcome.
Answer:
C
Explanation:
The helix has to unwind before separating. Once it's separated, then new bases can be added. Once the bases are added, the separate strands wind into helices.
If there are respiring organisms within that sample of air, the partial pressure of oxygen decreases because the organisms utilize it for respiration activities.
Answer:Yes
Explanation:
Only if someone down their bloodline has had 3 eyes. It would be possible, but highly unlikely.