DT - Genetic Material

Question 1

How are chromosomes seen?

Answer 1

AT or GC-rich regions are stained with dyes, a pattern of bands forms and is unique for each chromosome

Question 2

What is the full set of chromosomes known as?

Answer 2

Karyotype

Question 3

How does the Philadelphia chromosome form?

Answer 3

Translocation of material between chromosome 9 and chromosome 22

Question 4

How does Cystic Fibrosis occur?

Answer 4

A Mutant CFTR Channel does not move chloride ions and so sticky mucus builds up on the outside of the cell

Question 5

How does Sickle-Cell Disease occur?

Answer 5

A is changed to T on position 17
Glutamic Acid –> Valine
Low numbers of RBCs, infection and pain

Question 6

What was seen in the Griffith Experiment (1928)?

Answer 6

• Rough strain (non-virulent) did not affect the mice
• Smooth strain (virulent) killed the mice
• Heat-killed smooth strain did not affect the mice
  -Heat-killed smooth strain + rough strain killed the mice
  PROVES SOMETHING FROM A DEAD CELL TRANSFORMED INTO A LIVING CELL

Question 7

What was seen in the Avery Experiment (1944)?

Answer 7

The heat-killed smooth strain was mixed with the rough strain
- Added PROTEASE - Mice died
- Added RNase - Mice died
- Added DNase - Mice survived
PROVES DNA CONTAINS THE GENETIC MATERIAL CAUSING DEATH

Question 8

How was the Hershey and Chase experiment (1952) conducted?

Answer 8

1. Obtain bacteriophage
2. Label proteins with radioactive sulfur
3. Label DNA with radioactive phosphorous
4. Insert phage onto bacteria and determine whether any radioactivity is detected
5. Use a blender to remove phages
6. Centrifuge sample

Question 9

What can be proven from the Hershey and Chase experiment (1952) ?

Answer 9

Sulphur-35 not detected - Genetic material not contained in proteins
Phosphorous-32 detected- Genetic material held in DNA