Final answer:
Option (b) A B C D E F D E F G • H I is the correct representation of a tandem duplication of the gene sequence provided, where the segment D E F is consecutive and repeated in the chromosome.
Step-by-step explanation:
The subject of this question relates to genetics and specifically targets the concept of tandem duplication in chromosomes, a topic usually studied in high school biology. A tandem duplication occurs when a sequence of genes is repeated consecutively on the same chromosome.
Given the normal gene sequence A B C D E F G • H I, a tandem duplication would look like a sequence where part of the sequence is repeated directly after its initial appearance.
Using this definition, the option that correctly represents a tandem duplication in the given sequence is (b) A B C D E F D E F G • H I. Here, the segment D E F is repeated immediately after its first appearance, signaling a tandem duplication event.
This concept is essential in understanding how genetic variations can occur and the potential implications for organisms' development and health.