A strand of DNA is in the double helix structure.. you can think of it as two interconnected spiraling stairs
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This picture represents humoral immunity, please read through it, and if you dont understand which option is your answer then i would recommend you read more about this topic, if you want it to be done fast, you can read this http://www.s-cool.co.uk/a-level/biology/immunity/revise-it/the-third-line-of-defence
I hope you can come up with the answer on your own as it will be a good thing for you in your future exams :)
Surely i can help you if you dont understand something so just ask :D
Answer:
Yes.
Explanation:
The processes that formed the small stream bed are similar to those that formed the Grand Canyon because both are formed by the flowing of river. The river flow through these regions and with this flow they takes rock particles with itself and makes several shapes and structures of that region. So we say that rivers and streams are responsible for the formation of stream bed and Grand Canyon.