DNA viruses in which of the following families are relatively large and thus potentially
well suited for the introduction of genetic material in gene therapy?
a. Herpesviridae
b. Poxviridae
c. Papillomaviridae
d. Hepadnaviridae

Verified step by step guidance

1. Step 1: Understand the question is asking which DNA virus family has relatively large genomes, making them suitable vectors for gene therapy due to their capacity to carry additional genetic material.
2. Step 2: Recall that Herpesviridae viruses have large double-stranded DNA genomes, typically around 125-230 kilobase pairs (kbp), which allows them to carry extra genetic material.
3. Step 3: Consider Poxviridae, which are also large DNA viruses with genomes approximately 130-300 kbp, known for their complex structure and large genome size.
4. Step 4: Compare with Papillomaviridae and Hepadnaviridae, which have much smaller genomes (Papillomaviridae around 8 kbp and Hepadnaviridae around 3 kbp), limiting their capacity for gene insertion.
5. Step 5: Conclude that the families with relatively large genomes suitable for gene therapy vectors are Herpesviridae and Poxviridae, focusing on their genome size and ability to accommodate foreign DNA.

Key Concepts

DNA Virus Families and Their Characteristics

Different DNA virus families vary in genome size, structure, and complexity. Understanding these differences helps identify which viruses can carry larger genetic payloads, important for applications like gene therapy.

Genome Size and Its Importance in Gene Therapy

The size of a virus's genome correlates with its capacity to carry additional genetic material. Larger genomes allow for the insertion of therapeutic genes, making certain viruses more suitable as vectors in gene therapy.

Use of Viral Vectors in Gene Therapy

Viral vectors are engineered viruses used to deliver genetic material into cells. Selecting an appropriate virus depends on factors like genome size, host range, and safety, which influence the efficiency and feasibility of gene therapy.