Exam 1

Question 1

In prokaryotes the DNA forms a tangle known as a nucleoid

a) True
b) False

Answer 1

a)True

Question 2

All bacteria have cell wall

a) True
b) False

Answer 2

a)True

Question 3

In the DNA chain phosphodiester bonds join each deoxynycleotide

a) True
b) False

Answer 3

a)True

Question 4

In the double helix of DNA the DNA chains are join by

a) phosphodiester bonds
b) hydrogen bonds
c) covalent bonds

Answer 4

b)hydrogen bonds

Question 5

Meselson and Stahl’s experiment proved replication of DNA to be

a) Semiconservative replication
b) Conservative replication
c) Dispersive replication

Answer 5

a) Semiconservative replication

Question 6

The DNA polymerase I makes the Okazaki fragments

a) True
b) False

Answer 6

b)False

Question 7

The replication in the leading strand is

a) Continuous
b) Discontinuous
c) 3’—5’

Answer 7

a) Continuous

Question 8

In bacteria the replication is unidirectional

a) True
b) False

Answer 8

b)False

Question 9

In bacteria there are several origins of replication

a) True
b) False

Answer 9

b)False

Question 10

Replication continues until the replication fork enters a region of the chromosome called Ter

a) True
b) False

Answer 10

b)False

Question 11

The RNA polymerase makes a complementary copy of the DNA using the strand 5’—3’

a) True
b) False

Answer 11

b)False

Question 12

The tertiary structure of RNA is called a

a) hairpin
b) tRNA
c) Pseudonot

Answer 12

c) Pseudonot

Question 13

The promoter is recognized by the sub-unit alpha of the RNA polymerase

a) True
b) False

Answer 13

b)False

Question 14

In prokaryotes different types of RNA Polymerase synthesizes mRNA, tRNA and rRNA

a) True
b) False

Answer 14

b) False

Question 15

In the transcription the process in which the RNA polymerase recognizes and binds to a promoter sequence on DNA is called

a) Initiation
b) Elongation
c) Termination
d) None of these

Answer 15

a) Initiation

Question 16

. Which of the following is more likely to be a factor independent transcription termination site

a) 3’ ACTAGCCTAAGCATCTTGAGGCACAGAAAAAAAAATGC 5’
b) 3’ ACGTAAGGGTTTAAACGTACCCAAAAAAAAAAATCG 5’
c) 3’ AACGACTAGTACGACATACTAGTCGTTGGCAAAAAAAAAAAAAATG

Answer 16

c) 3’ AACGACTAGTACGACATACTAGTCGTTGGCAAAAAAAAAAAAAATG

Question 17

What is the longest ORF in the mRNA?

a) 5’ C AUG GAC UAA UCC UAG AUG UCG CGG GUU GAC AAU UUA ACU GUC GCG CCG GGU UCU GA 3’
b) 5’ CCCATGGACTAATAGATGTCGCGGGTTGACAATTTAACTGTCGCGCCGGGTTCTGA 3’
c) 5’ C AUG GAC UAA UCC UAG ACG UCG CGG GUU GAC AAU UUA ACU GUU GAC CCA CGU UU 3’

Answer 17

a) 5’ C AUG GAC UAA UCC UAG AUG UCG CGG GUU GAC AAU UUA ACU GUC GCG CCG GGU UCU GA 3’

Question 18

A sequence of three nucleotides in mRNA that specifies the first amino acid in the synthesis of a polypeptide chain

a) Codon
b) Anticodon
c) Start codon
d) Nonsense codon

Answer 18

c) Start codon

Question 19

What amino acid sequence would the DNA base sequence 5’ CGCATGAAAGAGCCT 3’ code for?

Answer 19

Arg-Met-Lys-Glu-Pro

Question 20

A complex consisting of a 30S ribosomal subunit, a tRNA having the anticodon UAC and carrying an altered form of the amino acid methionine (N-formylmethionine or f-Met), and proteins called initiation factors.

a) 50S or 60S ribosomal subunit
b) initiation complex
c) aminoacyl-tRNA

Answer 20

b) initiation complex

Question 21

The ribosomal subunit that binds to mRNA to form the initiation complex.

a) 30S ribosomal subunit
b) P-site of ribosome
c) A-site of ribosome
d) E-site of ribosome
e) 50S ribosomal subunit

Answer 21

a) 30S ribosomal subunit

Question 22

The ribosomal site where an aminoacyl-tRNA first attaches during translation.

a) 30S ribosomal subunit
b) P-site of ribosome
c) A-site of ribosome
d) E-site of ribosome
e) 50S ribosomal subunit

Answer 22

c) A-site of ribosome

Question 23

The ribosomal site where the growing amino acid chain is temporarily being held by a tRNA as the next codon in the mRNA is being read.

a) 30S ribosomal subunit
b) P-site of ribosome
c) A-site of ribosome
d) E-site of ribosome
e) 50S ribosomal subunit

Answer 23

b) P-site of ribosome

Question 24

Bacteria that cannot make or lacks the ability to grow on a particular nutrient.

a) Auxotroph
b) Prototroph
c) Mutant

Answer 24

a) Auxotroph

Question 25

Newcomb experiment proof the direct mutation hypothesis a) True b) False

Answer 25

b) False

Question 26

Mutations are permanent changes in the DNA sequence that are not inherited a) True b) False

Answer 26

b) False

Question 27

Transitions, transversions, missense mutations and Nonsense mutations are included in the a) Deletion mutations b) Inversion mutations c) Tandem duplications d) Frameshift mutations e) Base Pair Changes

Answer 27

e) Base Pair Changes

Question 28

Inversion is a mutation cause by cause by recombination between repeats and it can revert a) True b) False

Answer 28

b) False

Question 29

Suppression: alleviation of the effects of a mutation by second mutation elsewhere in the DNA a) True b) False

Answer 29

a) True

Question 30

Selection is a procedure in which bacteria are grown under conditions in which only the wild type or the desired mutant (or recombinant) can multiply, allowing the isolation of even very rare mutants (and recombinant) a) True b) False

Answer 30

a) True

Question 31

Cis acting mutation affect a functional region on the DNA molecule that does encode a gene product a) True b) False

Answer 31

b) False

Question 32

Procedure where using molecular genetic techniques in which a cloned gene is altered in the test tube and then reintroduced into the organism, then the altered gene replace the corresponding normal gene a) Transgenic b) Gene replacement c) Recombination

Answer 32

b) Gene replacement

Question 33

If a DNA strand reads 3’-TACGGCATG (where the names of the bases are abbreviated), then the RNA molecule created by transcription would read a) ATGCCGTAC b) AUGCCGUAC c) CGTAATGCA d) CGUAAUGCA

Answer 33

b) AUGCCGUAC

Question 34

In the bacterial chromosome replication the DnaA multimer complexes with ATP causes melting of an AT rich region to which another protein, DnaB/DnaC/ATP complex can then bind. a) True b) False

Answer 34

a) True

Question 35

Gene A contains a frameshift mutation. To revert that mutation (change it back to normal or wild type) you would use a a. mutagen causing transitions b. mutagen causing transversions c. mutagen causing frameshifts

Answer 35

c. mutagen causing frameshifts

Question 36

To revert a transition mutation you would use a a. mutagen causing transitions b. mutagen causing transversions c. mutagen causing frameshifts

Answer 36

a. mutagen causing transitions

Question 37

To revert a transversion mutation you would use a a. mutagen causing transitions b. mutagen causing transversions c. mutagen causing frameshifts

Answer 37

b. mutagen causing transversions

Question 38

Sec YEG : proteins that assist the non-covalent folding/unfolding a) True b) False

Answer 38

a) True

Question 39

A nucleic acid was analyzed and found to contain 32 percent A, 18 percent G, 17 percent C, and 33 percent T. The nucleic acid must be: a) single-stranded RNA b) single-stranded DNA c) double-stranded RNA d) double-stranded DNA

Answer 39

b)single-stranded DNA

Question 40

49. The Ter region is the area that contains multiple symmetrically arranged sites for trapping the replication fork. a) True b) False

Answer 40

a)True

Question 41

Resolution of Dimerized chromosomes__ a) Condensins b) Xer site-specific recombination system c) Formation of supercoil DNA occupy a smaller space d) Type II topoisomerase (Topo IV) removes the interlinks between the daughter DNAs

Answer 41

b) Xer site-specific recombination system

Question 42

Decatenation____ a) Condensins b) Xer site-specific recombination system c) Formation of supercoil DNA occupy a smaller space d) Type II topoisomerase (Topo IV) removes the interlinks between the daughter DNAs

Answer 42

d)Type II topoisomerase (Topo IV) removes the interlinks between the daughter DNAs

Question 43

Condensation___ a) Condensins b) Xer site-specific recombination system c) Formation of supercoil DNA occupy a smaller space d) Type II topoisomerase (Topo IV) removes the interlinks between the daughter DNAs

Answer 43

c)Formation of supercoil DNA occupy a smaller space

Question 44

Condensins_____ a) Condensins b) Xer site-specific recombination system c) Formation of supercoil DNA occupy a smaller space d) Type II topoisomerase (Topo IV) removes the interlinks between the daughter DNAs

Answer 44

a)Condensins

Question 45

49. Which mRNA codes for the following polypeptide: met arg ser leu glu a) 3'-AUGCGUAGCUUGGAGUGA-5' b) 3'-AGU GAG GUU CGA UGC GUA-5' c) 5'-AUG CGU AGC UUG GAG UGG-3' d) 1'-AUGCGUAGCUUGGAGUGA-3'

Answer 45

b) 3'-AGU GAG GUU CGA UGC GUA-5'