Final Answer:
The complementary sequence for the given DNA sequence, read from 3' to 5', would be: 5'-AGCTT-3'.
Step-by-step explanation:
In DNA, the complementary bases pair with each other: adenine (A) pairs with thymine (T), and cytosine (C) pairs with guanine (G). When determining the complementary sequence for a given DNA strand, it's crucial to recognize the base pairing rules. In this case, the original sequence given is 3'-GAATC-5'. To find its complementary sequence, each base needs to pair with its complement: G (guanine) pairs with C (cytosine), A (adenine) pairs with T (thymine), A (adenine) pairs with T (thymine), T (thymine) pairs with A (adenine), and C (cytosine) pairs with G (guanine). Reading the pairs in the opposite direction (from 3' to 5'), the complementary sequence becomes 5'-AGCTT-3'.
Understanding the directionality of DNA replication and transcription is crucial. DNA is read and synthesized in the 5' to 3' direction, so when specifying the complementary sequence in the 3' to 5' direction, it essentially represents the reverse of the original sequence. Using the base pairing rules, one can determine the complementary bases for each in the opposite direction to obtain the correct sequence. In this case, following the base pairing rules, the complementary sequence 5'-AGCTT-3' is derived by pairing each base with its complement in the reverse order of the given sequence, from 3' to 5'.