In the 1960s the molecular biologist George Streisinger developed the strand-slippage hypot esis, Streisinger noticed that mutations occurred in areas of DNA that contained many repeated sequences.When a strend-slippage error peairs, an insertion mutation can result. How does the insertion mutation affect the DNA? A. Nitrogenous bases are damaged. 8. Nitrogenous bases are exchanged, C. Nitrogenous bases are deleted. D. Nitrogenous bases are added.

## Step 1<br />The problem is about the effects of an insertion mutation on DNA. An insertion mutation is a type of mutation where one or more nucleotides are added to the DNA sequence. This can happen due to a variety of reasons, such as errors during DNA replication or exposure to certain chemicals.<br /><br />## Step 2<br />The options provided are:<br />A. Nitrogenous bases are damaged.<br />B. Nitrogenous bases are exchanged.<br />C. Nitrogenous bases are deleted.<br />D. Nitrogenous bases are added.<br /><br />## Step 3<br />The correct answer is D. Nitrogenous bases are added. This is because an insertion mutation involves the addition of one or more nucleotides to the DNA sequence.