Ch12 - DNA & RNA

Question 1

What happens in transformation?

Answer 1

One thing/strain is changed to another

Question 2

What experiment did Griffith do?

Answer 2

• Goal: vaccine of pneumonia
• used 2 bacteria strains
  
  • 1. R strain - does not cause pneumonia
  • 2. S strain - causes pneumonia
• He tested to find that when R strain & heat-killed S strain are together, the organism dies of pneumonia

Question 3

What is the structure of a virus?

Answer 3

DNA on the inside
protein on the outside

Question 4

Who initially discovered DNA? How?

Answer 4

Oswald Avery (1944)
Goal: determine what caused the transformation principle
- He enzymatically destroyed certain components to find that DNA caused this change
- He double checked using nitrogen and phosphorus concentration

Question 5

What did Hershey-Chase do/find?

Answer 5

Studied bacteriophage
Goal: was genetic material made of protein or DNA
- Used radioactive isotopes to identify whether the virus injected sulfer or phosphorus
Result: genetic material is made of DNA

Question 6

What are the 3 main roles of genes?

Answer 6

• Carry information
• Help information come to use
• easily replicated

Question 7

What are the components of DNA?

Answer 7

nucleotides
- 5 carbon sugar (deoxyribose)
- phosphate group
- nitrogenous bases

Question 8

What are bacteriophage?

Answer 8

bacteria eaters

Question 9

Who discovered base pairing rule & what is the rule?

Answer 9

Erwin Chargaff

Adenine – Thymine
Cytosine — Guanine

A & G - purines
T & C - pyrimidines

Question 10

What did Rosalind Franklin do/find?

Answer 10

Worked with X-ray crystallography to identify structure of DNA
- found X shape which suggested helical 2 stranded structure

Question 11

What did Francis Crick & James Watson do/find?

Answer 11

used 3d model to add on to franklins work
- found out about antiparallel structure
- right handed helical
- sugar & phosphate backbone + nitrogenous base inside

Question 12

What is DNA’s antiparallel structure?

Answer 12

3’<–>5’
3’ = hydroxyl group
5’ = phosphate group

Question 13

What is the structure of chromosomes/dna?

Answer 13

chromatin tightly condensed around histone (proteins)

Question 14

Structure of chromosomes in eukaryotes vs. prokaryotes?

Answer 14

Eukaryotes: 1000x amt of dna in nucleus
Prokaryotes: circular DNA in cytoplasm

Question 15

When does DNA replication occur?

Answer 15

S phase of interphase

Question 16

What are telomeres? Enzyme function?

Answer 16

telomeres- tips of dna that are very difficult to replication
telomerase assists this replication

Question 17

DNA replication in eukaryotes vs. prokaryotes

Answer 17

eukaryotes: starts at many sites
prokaryotes: circular dna - starts at 1 point and goes in 2 directions

Question 18

Transcription? Enzyme used?

Answer 18

copying DNA to make mRNA
using RNA polymerase, primase, and promoter section

Question 19

Translation?

Answer 19

translating the codons from mRNA into amino acids/ polypeptide chain

Question 20

What are promoters?

Answer 20

section of DNA strand that is used to bind polymerase

Question 21

Types of mutations

Answer 21

Gene mutations & Chromosomal mutations

Question 22

Point mutations vs frameshift

Answer 22

point mutation: affects a single/few nucleotides
- substitution, insertion, deletion
frameshift: affects large section and alters protein production

Question 23

Types of chromosomal mutations

Answer 23

Deletion:
Duplication
Inversion: reverse the direction of parts of chromosome
translocation: part of 1 chromosome attaches to another

Question 24

Causes of mutation

Answer 24

Environment - UV, radiation
DNA replication errors

Question 25

Importance of mutations

Answer 25

genetic variability

Question 26

What are silent mutations

Answer 26

• don’t cause a change
• because many codon combinations code for the same amino acid