Genetics Chapter Nine - Experiments

Question 1

How do we use DNA and in what fields

Answer 1

• Forensics
• Medical Biosciences
• Biological research

Question 2

What are the applications of DNA

Answer 2

• Curing Diseases
• Developing treatments
• Discovering new species

Question 3

Explain the link between genetic material and traits

Answer 3

• Frederick Griffith ( 1928 )
• Pneumonia = serious disease and there was no vaccine
• 2 Strains of Bacterium Streptococcus pneumonia

1. Smooth surface ( S ) - protective capsule
2. Rough Surface ( D ) - no protective capsule

• Type S causes an infection when present in an animal and causes it to get sick
  but R type doesn’t cause an infection

Question 4

How did they determine which strain caused an infection

Answer 4

• Tested strains on mice
  ( injected the 2 different strains into 2 separate mice
• Recorded how many mice died and counted number of bacterium in blood of dead mice
  • Bacterium has to survive and replicate to kill

Question 5

What is the defining Characteristic and its role in Griffiths experiment

Answer 5

• The capsule
• Protection from the immune system of the host thus can replicate

Question 6

Explain Griffiths third experiment

Answer 6

• He killed the S - Strain bacterium by adding heat to see if the dead bacteria would kill mice
  - which it didn’t and didn’t cause the disease

Question 7

Explain Griffiths 4th experiment

Answer 7

• Mixed heat killed S strain and added it to type R and then into the mice
  
  • all the mice died
• Found only S Strain in mice meaning that a transformation had taken place thus the R Strain took smooth coat characteristic

Question 8

What were the outcomes of Griffiths experiments

Answer 8

• The trait responsible for the development of the disease was from the dead s-strain to the live r strain
• This means that genetic material codes for particular traits and theirs a transfer of genetic material in bacterium

Question 9

How do bacterium replicate

Answer 9

Mitosis

Question 10

Explain Oswald Avery and others fully

Answer 10

• 1944
• Found that when a solution of the combo heat killed type S - Strain and R-Strain was treated with protein destroying enzyme, the combo of the heat killed s and r still killed mice
• Thus a protein was not transmitting the killing trait which was transforming there strain to s strain

Question 11

Explain the contents of nuclei

Answer 11

• Nucleic acids
  
  • DNA & RNA

Question 12

What are nucleic acids made up of

Answer 12

Nucleotides

Question 13

Explain nucleotides

Answer 13

• Nitrogen containing groups
• One or more phosphate containing components
• Sugars

Question 14

Where is the sugar found on DNA and RNA

Answer 14

• DNA = an H on second C
• RNA = An OH-group on the second C