Question

The 5' end of a DNA molecule can be chemically distinguished from the 3' end because there is a(n) __________ group at the 5' end and a(n) __________ group at the 3' end.

Answer 1

Answer:

The words which complete the two spaces are:

1. free hydroxyl or phosphate and
2. free hydroxyl  

Explanation:

So the complete sentence will read as follows:

The 5' end of a DNA molecule can be chemically distinguished from the 3' end because there is a free hydroxyl or phosphate group at the 5' end and a free hydroxyl group at the 3' end.

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