Exam 2 In-class Review

Question 1

Difference of bacterial DNA and Archaeal DNA and Eukaryal DNA

Answer 1

• Eukaryal is linear

- Archaeal and bacterial is circular

Question 2

replication of bacterial chromosome begins at how many locations

Answer 2

one

Question 3

After DNA is unwound at site of DNA replication initiation, what binds to unwound DNA to prevent it from reannealing

Answer 3

single strand of DNA (binding protein)

Question 4

which enzyme removes RNA primer and fills in the gap during DNA replication in bacteria?

Answer 4

DNA polymerase 1

Question 5

what is a codon?

Answer 5

3 bases on the mRNA that is read by ribosome for 5’ to 3’ direction

Question 6

the viral attachment protein binds specifically to the host cell receptor. What are examples of Host cell receptors?

Answer 6

protein, glycoproteins, lipopolysaccharides, sialic acid

DNA is NOT

Question 7

2nd step of viral replication for entry in bacteriophages.is

Answer 7

direct entry of the nucleic acid into the cell

Question 8

HIV enters the cell through a ______

Answer 8

membrane fusion

*since its membrane fusion it must be a enveloped virus

Question 9

Fuzeon is an antiviral drug that prevents membrane fusion for entry into the cells by HIV. the mode of action is

Answer 9

to bind ot gp41 membrane fusion protein on HIV

Question 10

Class 3 viruses are double stranded RNA viruses and use the following polymerase for genome synthesis?

Answer 10

viral RNA-dependent RNA polymerase

Question 11

what is “sexual transfer of genes in bacteria called?

Answer 11

conjugation

Question 12

compared to eukaryal chromosome, the bacterial chromosome

Answer 12

contains genes that are usually present in only 1 copy

Question 13

what is an organisms complete collection of alleles called?

Answer 13

genotype

Question 14

Mutant eschenia coli K12 contains a mutant trpE gene and cant make tryptophan. what is the mutant called?

Answer 14

an auxotroph

Question 15

uptake of extracellular DNA onto a bacterial cell and incorporates into its genome?

Answer 15

transformation

Question 16

term for sanger method of DNA sequencing

Answer 16

dideoxy sequencing

Question 17

sanger method has been automated and uses what?

Answer 17

a thermal stable DNA polymerase to allow for multiple rounds of DNA synthesis

NOT radioactive nucleotides

Question 18

what is an open reading frame

Answer 18

protein encoding sequence of a gene

Question 19

scientist put genes in GenBank so they’re publicly available. How many base pairs have been deposited thus far?

Answer 19

greater than 10 million

Question 20

what was the Northern Blot Hybridization technique use for?

Answer 20

to measure the transcriptional expression of a specific gene

Question 21

Are expression of genes that are constitutive regulated?

Answer 21

no, unregulated

Question 22

expression of genes required for Biofilm formation only happens after a cell has attached to a surface suitable for Biofilm development. This type of gene expression is

Answer 22

induction

Question 23

During negative regulation of a gene expression the repressor protein binds to the operator to inhibit transcription. the effector molecule that controls activity of the repressor protein is

Answer 23

corepressor or inducer

Question 24

which of these controls the expression of the lac operon?

Answer 24

both repression and activator mechanisms

* activator is high in cyclic AMP, catabolic receptor protein bind to the AMP which binds to the copsighe

Question 25

how will E. coli growing in a medium contain both lactose and glucose react?

Answer 25

e.coli will preferentially use glucose and when its gone it will use lactose. This is called Dioxic Growth Curve