Mutations, gene therapy, kidney

Question 1

Which blood vessel takes blood INTO the kidney?

Answer 1

Renal artery

Question 2

Which blood vessel takes blood OUT of the kidney?

Answer 2

Renal vein

Question 3

Which is wider, the afferent arteriole or the efferent arteriole?

Answer 3

The Afferent arteriole = Wider than the Efferent arteriole

Question 4

The glomerular filtrate passes along the ____ to the bladder, to the _____

Answer 4

The glomerular filtrate passes along the URETER to the bladder, to the URETHRA

Question 5

What is the very middle section of the kidney called?

Answer 5

The Pelvis

Question 6

What is the outer layer of the kidney called?

Answer 6

The cortex

Question 7

What is the inner layer of the kidney called, where the loop of Henle’s are located?

Answer 7

The medulla

Question 8

What are the three layers that blood has to pass through to get into the Bowman’s capsule?

Answer 8

1) Capillary fenestrations
2) ‘Basement membrane’
3) Bowman’s capsule epithelium (containing podocytes)

Question 9

What does gene therapy involve?

Answer 9

Altering the defective genes (mutated alleles) inside cells to treat genetic disorders and cancer

Question 10

How does gene therapy work when the disorder is caused by a mutated dominant allele?

Answer 10

One can ‘silence’ the dominant allele – insert a DNA fragment in the middle of the allele so it becomes dysfunctional. Just like in vivo cloning.

Question 11

How does gene therapy work when the disorder is caused by two mutated recessive alleles?

Answer 11

One can add a working dominant allele to ‘supplement’ the faulty ones.

Question 12

Gene therapy

How does one get the ‘new’ allele (DNA) inside the cell?

Answer 12

The allele is inserted into cells using vectors,
just like in recombinant DNA technology

Different vectors can be used e.g.
viruses, plasmids or liposomes.

Question 13

State four requirements for gene therapy

Answer 13

The disorders:

a) Must be well understood
b) Faulty gene identified and working copy available
c) Cells requiring treatment are accessible
d) Suitable means of delivery

Question 14

State the two types of gene therapy

Answer 14

Somatic and germ line

Question 15

What does somatic therapy involve?

Answer 15

It involves altering the alleles in body cells, particularly the cells that are most effected by the disorder

Question 16

What does germ line therapy involve?

Answer 16

It involves altering the alleles in the germ (sex) cells

Question 17

State some advantages of gene therapy

Answer 17

• It could prolong the lives of people with genetic disorders
• It could give people with genetic disorders a better quality of life
• Carriers of genetic disorders might be able to conceive a baby without that disorder (germ line therapy)
• It could decrease the number of people that suffer from genetic disorders (germ line therapy)

Question 18

State some disadvantages of gene therapy

Answer 18

• The effects of the treatment may be short-lived (somatic therapy)
• The patient may have to undergo multiple treatments (somatic therapy)
• It might be difficult to get the allele into specific body cells
• The body could identify vectors as foreign bodies and start an immune response against them
• An allele could be inserted into the wrong place in the DNA, this could cause more problems
• An inserted gene could get over-expressed, producing too much of the missing protein
• Disorders caused by multiple genes (e.g. cancer) would be difficult to treat with this technique
• There are many ethical issues e.g. creating ‘super races’ and ‘designer babies’.