Genetics Test

Question 1

What did Meischer study? What did he discover?

Answer 1

• studied pus
• identified substance in cells he called ‘nuclein’

Question 2

What did Briggs + King study?

Answer 2

• frog eggs

Question 3

What was Briggs + King’s first experiment?

Answer 3

• they removed nucleus from frog egg
• no frog grew

Question 4

What was Briggs + King’s second experiment?

Answer 4

• used 2 different frogs
• they placed nucleus of frog B into egg of frog A
• frog b grew

Question 5

What was Briggs + Kings conclusion?

Answer 5

• genetic material is in the nucleus

Question 6

What did Griffith study?

Answer 6

• mice/pneumonia
  -2 strains of pneumonia
  A) S strain (smooth -> capsule)
  B) R strain (rough -> no capsule)

Question 7

What were the findings of Griffith’s experiments?

Answer 7

1) mice + S strain -> death
2) mice + R strain -> live
3) mice + heat killed S strain -> live
4) mice + heat killed S strain + R strain -> death

• Transforming Principle*

Question 8

What did Avery, Mcleod, and McCarty study? What was their conclusion?

Answer 8

• streptococcus
  1) heat killed S strain + digested RNA and protein of R strain -> death
  2) heat kill S strain + digested DNA of R strain -> live
  3) heat kill S strain + digested RNA and DNA of R strain -> live
• concluded DNA is genetic material

Question 9

What did Hershey/Chase study? What was their conclusion?

Answer 9

• radio isotopes/bacteriophage
  Labelled: DNA - P32
  Protein - S35
  -after infection they found P32 in the cells
• concluded DNA is the genetic material

Question 10

What was Chargraff’s contribution?

Answer 10

• chemical analysis of DNA
• A,T,G,C
• A proportional to T
• G proportional to C

Question 11

What did Franklin (Wilkins) do?

Answer 11

• X ray crystallography
• Double helix shape

Question 12

What did Watson/Crick conclude?

Answer 12

• structure of DNA
  *NOT 1 experiment
  1)Phosphate-sugar backbone
  2) Rungs of ladder are N bases - held by H bonds
  A-T (2H), G-C (3H)
  3) Double helix
  4) Antiparallel

Question 13

Is DNA replication conservative, semiconservative, or disruptive?

Answer 13

• DNA replication is semiconservative

Question 14

What are the 3 steps of DNA replication?

Answer 14

1) Strand separation: unwind, break H bonds
2) Build complementary strand
3) Fix errors - edit

Question 15

What is the location and function of Topoisomerase?

Answer 15

Location - above replication fork
Function - eases tension of unwound strand

Question 16

What is the location and structure of Helicase?

Answer 16

Location - at replication fork
Function - breaks H bonds

Question 17

What is the location and function of SSB’s (single stranded bonding protein)?

Answer 17

Location - attach to open strands below replication fork
Function - prevents reannealing

Question 18

What is the location and function of RNA primase?

Answer 18

Location- at end of leading strand
-many points of lagging strand
Function - adds RNA primer

Question 19

What is the location and function of RNA primer?

Answer 19

Location - end of leading
-many on lagging
Function - starting point for DNA polymerase III

Question 20

What is the function of DNA Polymerase III?

Answer 20

Function - add N bases to new strand
- works in 5’ to 3’ direction

Question 21

What is the location and function of DNA Polymerase I and II?

Answer 21

Location - follow DNA polymerase III
Function - proof read
-fix errors

Question 22

What is the function of ligase?

Answer 22

Function - glue okasaki fragments together

Question 23

What is a codon?

Answer 23

3 nitrogen bases - codes for 1 amino acid

Question 24

What is transcription and where does it occur?

Answer 24

• copy DNA into RNA
• in the nucleus

Question 25

What enzyme is involved in transcription?

Answer 25

RNA polymerase

Question 26

What are the 3 steps of transcription?

Answer 26

1. Initiation
2. Elongation
3. Termination

Question 27

What are the 3 post transcriptional modifications?

Answer 27

• cut out introns, add 5’ cap, add Poly A tail

Question 28

What is tRNA also called?

Answer 28

• also called anticodon

Question 29

What is translation?

Answer 29

Reading mRNA and making protein

Question 30

Where does translation occur?

Answer 30

On the ribosome

Question 31

What 3 types of RNA are involved in translation?

Answer 31

1.mRNA - message from the DNA
2. tRNA - bring the amino acid’s down
3. rRNA - site on ribosome

Question 32

What is a mutation?

Answer 32

• any change to the DNA

Question 33

What is a small scale mutation? What is it also known as?

Answer 33

• a change in a single base pair or small group
• also know as point mutations

Question 34

What are the 4 types of small scale mutations?

Answer 34

1) Missense
2) Nonsense
3) Silent
4) Frameshift

Question 35

What is a large scale mutation?

Answer 35

Affects multiple codons, entire genes, or large regions of a chromosome

Question 36

What are the 5 types of large scale mutations?

Answer 36

1) Amplification (aka duplication)
2) Deletion
3) Translocation
4) Transposition
5) Trinucleotide repeat

Question 37

What are the 2 causes of mutations?

Answer 37

1) Spontaneous Mutations - mistakes during DNA replication
2) Induced Mutation - caused by an environmental factor
-Mutagen - causes induced mutations
-Carcinogen - causes a mutation which leads to cancer

Question 38

What are operons?

Answer 38

• control transcription
• beginning of every gene