Answer: double helix
Explanation: The double helix of DNA is, like its name implies, in the shape of a helix which is essentially a three dimensional spiral. The double comes from the fact that the helix is made of two long strands of DNA that are intertwined—sort of like a twisted ladder.
Answer:
The quantity of water.
Explanation:
The independent variable is changed or controlled during an experiment and should have a direct effect on the dependent variable.
A vaccine is a medical material that mimics the pathogen, but in a harmless way. When our body's immune fights it off, it remembers how to fight the real pathogen when it enters our body. So, it protects us from diseases.