Question

1) During the 1950's, several scientists were responsible for discovering the structure of DNA. One scientist, Erwin Chargaff, found that in DNA, the ratios of adenine (A) to thymine (T) and guanine (G) to cytosine (C) are always equal. What does Chargaff's discovery indicate about the structure of DNA and its impact on replication? All BUT ONE choice could apply.

A.)Adenine pairs with thymine; guanine with cytosine.
B) The base pairing facilitates DNA replication and RNA transcription. Eliminate
C) When pairing nucleotides, you must pair a purine with a pyrimidine.
D) If we read the sequence of nucleotides on one strand of DNA, we can identify the complementary sequence on the other strand.

Answer 1

Chargaff's rules demonstrate the base pairing relationships in DNA, with adenine pairing with thymine, and guanine with cytosine, which is vital for the structure of the double helix and the accuracy of DNA replication.

Step-by-step explanation:

Erwin Chargaff's discovery indicates several crucial aspects of DNA's structure and its impact on replication. First, Chargaff's rules tell us that the amount of adenine (A) is always equal to the amount of thymine (T), and the amount of guanine (G) is always equal to the amount of cytosine (C) in DNA. This shows that adenine pairs with thymine, and guanine pairs with cytosine, which is fundamental to the double-helix structure that James Watson and Francis Crick later discovered.

Moreover, this complementary base pairing is essential for DNA replication because it enables each strand to serve as a template for creating a new complementary strand. This ensures the genetic code is precisely copied with each cell division. Secondly, because you must pair a purine (A or G) with a pyrimidine (T or C), the double helix maintains a constant diameter. Lastly, knowing the sequence on one strand allows us to predict the complementary sequence on the other strand, crucial for replication and transcription processes.