gene therapy

Question 1

What is gene therapy and what does it aim to treat? (2)

Answer 1

The process of altering defective genes inside cells to treat genetic disorders and cancer;

Defective genes are usually mutated alleles

Question 2

How can gene therapy treat diseases caused by two mutated recessive alleles? (1)

Answer 2

By adding a working dominant allele

Question 3

How can gene therapy treat diseases caused by one mutated dominant allele? (2)

Answer 3

Silence the dominant allele by inserting a piece of DNA into the middle of the allele;

Preventing it from producing a functional protein

Question 4

What vectors can be used to insert new DNA in gene therapy? (1)

Answer 4

Vectors such as altered viruses, plasmids, or liposomes can be used to insert new DNA

Question 5

What is somatic gene therapy? (2)

Answer 5

Somatic therapy involves altering alleles in body cells;

It doesn’t affect sex cells, so offspring could still inherit the disease

Question 6

What are the limitations of somatic therapy? (3)

Answer 6

Effects may be short-lived, requiring multiple treatments;

It can be difficult to target specific cells;

The procedure may be invasive or dangerous

Question 7

What is germ line gene therapy, and why is it controversial? (3)

Answer 7

Alters alleles in sex cells;

Affecting all future offspring;

It is currently illegal.

Question 8

What are some risks associated with gene therapy? (3)

Answer 8

The body could identify vectors as foreign bodies, leading to an immune response;

An allele might be inserted in the wrong place, causing problems;

Could be over-expressed, producing too much of the protein