DNA structure and analysis 1

Question 1

forms the basis of genetic info

Answer 1

DNA

Question 2

Who performed the experiments that confirmed, for the first time, DNA is the genetic material (and not proteins)

Answer 2

Avery

Question 3

Double helix

Answer 3

Watson and Crick

Question 4

To be classified as genetic info the molecule must have:

Answer 4

1. Replication
2. storage
3. Expression of stored genes
4. Variation through mutation

Question 5

1. Replication

Answer 5

Meiosis and mitosis
- During mitotic division:
Full copy must be passed to every daughter cell (Identical)
Gametes: must receive half of the DNA material

Question 6

2. Storage:

Answer 6

Must be able to store genetic material in cell.
HOWEVER - not all material is expressed at all time
- Some expressed always, sometimes and never in a particular cell

Question 7

Genes that are always expressed

Answer 7

Constitutive genes

Question 8

3. Expression of stored genes

Answer 8

[ Central Dogma ]

                    DNA
                       |
             Transcription 
             |          |          |
       mRNA   tRNA    rRNA 
           \             |            /
                Ribosomes
                         |
                Translation
                         |
                   Protein

Question 9

Explain expression

Answer 9

1. Genes are stored and then identically replicated
2. To be expressed, they must first be transformed - via RNA = transcription
3. mRNA carries genetic info from DNA for production of most proteins
   > each mRNA has info encoded by a specific gene = synthesis of specific protein
4. At the ribosomes; the info encoded on mRNA is translated into protein - mediated by tRNA and rRNA
5. During translation - info encoded on mRNA directs the synthesis of a growing chain of amino acids to form a polypeptide
   –> eventually folds into protein
   = Central Dogma

Question 10

Central dogma

Answer 10

Info stored in DNA which directs the formation of RNA during transcription and then directs the formation of proteins via translation

Question 11

4. Variation through mutation

Answer 11

Occurs in DNA:
Changes carried through transcription and translation = affects specific proteins

Occurs in gametes:
Can pass on to off-spring = distributes through population ( basis of evolution)

Question 12

Use notes for historical back ground section!