Genetics

Question 1

How many base pairs does E.Coli have?

Answer 1

5x10^6

Question 2

How many base pairs does human cell have?

Answer 2

3x10^9

Question 3

How many proteins does E.Coli Gene encode?

Answer 3

2000

Question 4

How many proteins does human cell gene encode?

Answer 4

100,000

Question 5

Define conditional lethal mutation

Answer 5

It’s a mutation only lethal under restrictive conditions (but may function under permissible conditions)

Question 6

What is a silent mutation?

Answer 6

Change of codon but still codes for the same amino acid

Question 7

What is a missense mutation?

Answer 7

Change in codon that causes change in amino acid being made

Question 8

What is a non-sense mutation?

Answer 8

Change in codon that produces a stop signal

Question 9

What is a frame shift mutation?

Answer 9

One or more base are added or deleted leading to shift the reading frame = inactive protein

Question 10

4 examples of naturally transformable bacteria?

Answer 10

1) streptococcus pneumonia
2) haemophilus influenzae
3) Neisseria gonorrhoea
4) vibrio cholera

Question 11

Define transformation?

Answer 11

Taking naked DNA
(usually dead bacteria)

Question 12

Define transduction?

Answer 12

Gene transported by bacteriophage from one bacteria to another

Question 13

Give 4 example on lysogenic conversion?

Answer 13

Corynebacterium diphtheria
Vibrio cholera
Clostridium botulinum
Streptococcus pyogenes

Question 14

Define conjugation?

Answer 14

Plasmids move by cell-cell contact

Question 15

Define the two types of competence in transformation

Answer 15

Natural competence
&
Artificial competence
(by electroporation)

Question 16

What are the states of a bacteriophage?

Answer 16

Lytic & temperate (lysogen)

Question 17

What are the phage & bacteria called during lysogeny?

Answer 17

The phage: Prophage
The bacteria: lysogen

Question 18

Define lysogenic conversion

Answer 18

Change of lysogen phenotype after the phage encodes an observable function

Question 19

What is the toxin produced from streptococcus pyogenes & what is the disease?

Answer 19

Erythrogenic toxin which causes scarlet fever

Question 20

Generalized vs specialized transduction ?

Answer 20

Generalized: All of the capsid is filled with random bacterial genome

Specialized: a specific part of bacterial genome is mixed with the virus’ own genome in the capsid

Question 21

How is the genome for virulence exchanged ?

Answer 21

By generalized transduction

Question 22

How is the genome for antibiotic resistance exchanged ?

Answer 22

Generalized transduction
Or Transposons

Question 23

How is the genome for multiple antibiotic resistance exchanged ?

Answer 23

Conjugation