The Hereditary Material - MT3 - Part 2

Question 1

What book did Erwin Schrodinger write?

Answer 1

What is life?

Question 2

What was Schrodinger the founder of?

Answer 2

Wave mechanics

Question 3

What might the study of living matter reveal?

Answer 3

Previously unknown laws about physics

Question 4

What must genes be made up?

Answer 4

Of a max of a few 100 to a few 1,000 atoms

Question 5

Why must genes have a specific make up?

Answer 5

To account for genetic stability

Question 6

What happens if you have more than 1000 atoms in a gene?

Answer 6

You could allow for too-frequent gene destruction by the thermal disruption of covalent bonds

Question 7

What must genes be?

Answer 7

Aperiodic crystals

- every atom or group of atoms has a particular place and role in the gene

Question 8

What did the model “sugar coated microbe”, streptococcus pneumoniae show?

Answer 8

That genes are made up of DNA

Question 9

What 2 strains are there in streptococcus pneumoniae?

Answer 9

1. S (smooth) strain

2. R (rough) strain

Question 10

S strain (2)

Answer 10

1. Causes pneumonia in mice
2. It is surrounded by a slimy polysaccharide coat that renders it invisible to the mouses immune system
   - acts as an invisibility cloak on the mouse

Question 11

R strain (2)

Answer 11

1. Harmless to the mouse

2. Not surrounded by a slimy polysaccharide coat, so it is visible to the mouses immune system, which deals with it

Question 12

What did Fred Griffith discover?

Answer 12

The transformation of the nonvirulent R strain of streptococcus pneumoniae to the virulent S strain

Question 13

What did Oswald Avery, Maclyn McCarthy and Colin MacLeod suggest about what molecule carried the hereditary information between cells?

Answer 13

Perhaps a heritable factor (a gene) is transferred from the remains of the dead S cells to the living R cells, enabling the R cells to make a protective polysaccharide coat

• thus the R cells become S cells, hereditary
• only the enzyme that extracted from the DNA actually stopped the transformation (from R-S)

Question 14

What did Alfred Hershey, Martha Chase and T2’s experiment explain?

Answer 14

The heritability factors are transformed and carry genetic information

Question 15

What do phages do to replicate?

Answer 15

They inject their genes into a host bacterial cell, which expresses the genes and makes more phage particles
- can radioactively label them so we can observe it

Question 16

When phages inject their genes into the host cell, what are they injecting?

Answer 16

DNA

- not proteins

Question 17

What is sulphur in?

Answer 17

Proteins

- not DNA

Question 18

What was Watsons big question?

Answer 18

What was the shape of DNA

Question 19

What was Pauling the first to present?

Answer 19

The alpha helix of the phosphorous backbone

Question 20

What was Chargaffs rule?

Answer 20

1. A pairs with T and G pairs with C
2. These bases were present in equal amounts
   - but the amounts of A/T different from the amount of G/C

Question 21

What are hooked strands of nucleotides called?

Answer 21

Polynucleotides

Question 22

What dod Maurice Wilkins and Rosalind Frankiln make?

Answer 22

X-ray diffraction pictures of crystallize DNA

Question 23

The central dogma

Answer 23

A theory in genetics and molecular biology subject to several expectations that genetic information is coded in self-replicating DNA and undergoes unidirectional transfer to mRNA in transcription which act as templates for protein synthesis in translation

Question 24

What kind of connotation did dogma have?

Answer 24

A negative one as it was used with the religious and political views and acceptance of authority

Question 25

What did Watson and Crick first propose for the shape of DNA?

Answer 25

That it was a triple helix

• 3 polynucleotide strands
• bases were pointing out
• phosphorous groups were pointing in

Question 26

What Watson and Crick discovered they were wrong about the triple helix, what did they propose for the shape?

Answer 26

That DNA is a double helix

• like with like pairing
• eg) A-A, T-T, G-G, C-C

Question 27

What did the double helix with A-T and G-C pairings explain?

Answer 27

Chargaffs rule

Question 28

What does Crick point out?

Answer 28

That the 2 strands must run in opposite direction

- antiparallel