M2: FUNDAMENTALS OF MOLECULAR BIOLOGY

Question 1

What is the genetic material of all living organisms and some viruses ?

Answer 1

DNA

Question 2

What is the genetic material of only certain viruses ?

Answer 2

RNA

Question 3

What genetic material is found in prokaryotes and eukaryotes ?

Answer 3

double-stranded DNA

Question 4

What genetic material is found in viruses ?

Answer 4

double or single-stranded DNA or RNA

Question 5

What are the units of measurements of single-stranded nucleic acids ?

Answer 5

nucleotide (nt)

Question 6

What are the units of measurements of double-stranded nucleic acids ?

Answer 6

base pairs (bp)

Question 7

According to who’s model does the DNA molecule consists of two polynucleotide chains joined by hydrogen bonds ?

Answer 7

Watson and Crick’s

Question 8

What are the three major types of DNA determined by analyzing DNA outside the cell ?

Answer 8

right handed A and B-DNA and the left-handed Z-DNA

Question 9

What is the common form of DNA found in cells is closest in structure to ?

Answer 9

B-DNA

Question 10

A ___ chromosome is compacted into the nucleoid region by the supercoiling of the DNA helix and the formation of looped domains of supercoiled DNA

Answer 10

bacterial

Question 11

The complete set of metaphase chromosomes in a eukaryotic cell is called it’s ___

Answer 11

karyotype

Question 12

The more condensed a region of a chromosome is, the less likely it is that the genes in that region will be active. T or F

Answer 12

T

Question 13

What part of the eukaryotic chromosome is responsible for the accurate segregation of the replicated chromosome to the daughter cells during mitosis and meiosis ?

Answer 13

centromere region

Question 14

What are the ends of eukaryotic chromosomes called ?

Answer 14

Telomeres

Question 15

What repetitive sequences have the capability of moving to other locations in the genome ?

Answer 15

Transposons

Question 16

What do you call the occurrence where two strands of DNA are separated and a new complementary strand of DNA is synthesized in the 5 to 3 direction on each of the two parental template strands ?

Answer 16

Semiconservative mechanism

Question 17

What enzymes catalyze the synthesis of DNA ?

Answer 17

DNA polymerases

Question 18

Using __ precursor, all DNA polymerases make new strands in the 5 to 3 direction

Answer 18

dNTP

deoxy ribonuclease 5’ - triphosphate

Question 19

Function of DNA primase ?

Answer 19

synthesize a short RNA primer to provide a 3’ - OH group provided by the primer

Question 20

the synthesis of DNA is continuous on one template strand and discontinuous on the other template strand

Answer 20

demidiscontinous replication

Question 21

In eukaryotes what phase of the cell cycle does DNA replication occur in ?

Answer 21

S phase

Question 22

Difference between where DNA replication begins at for prokaryotes and eukaryotes ?

Answer 22

prokaryotes: begins at a single replication origin
eukaryotes: initiated at many replication origins along each chromosome

Question 23

What happens in the absence of telomerase activity in a cell ?

Answer 23

progressive shortening of chromosome ends as the cell divides, thereby limiting the number of somatic cell divisions

Question 24

Nucleosome assembly is an orderly process directed with the aid of __

Answer 24

histone chaperones

Question 25

This is the process of copying genetic information in DNA into RNA base sequences

Answer 25

Transcription

Question 26

Is it true all four main classes of RNA is found in both prokaryotes and eukaryotes ?

Answer 26

small nuclear RNA (snRNA) is found only in eukaryotes

Question 27

In E. coli, the initiation of transcription of protein coding genes requires a complex of ___

Answer 27

RNA polymerase and the sigma factor protein binding to the promoter

Question 28

RNA polymerase 1 transcribes the genes for the ___ ___ and ___ ribosomal RNAs

Answer 28

18S, 5.8S, and 28S

Question 29

RNA polymerase 2 transcribes ___ genes and some ___ genes

Answer 29

mRNA

snRNA

Question 30

RNA polymerase 3 transcribes genes for the ___, ___, and ___

Answer 30

5S rRNAs
tRNAs
other snRNA

Question 31

Eukaryotic RNA polymerases are unable to bind to promoters directly. T or F

Answer 31

T

Question 32

What are the three main parts of mRNAs ?

Answer 32

5’ untranslated region (UTR)
the amino acid coding sequence
3’ untranslated region

Question 33

In prokaryotes the gene transcript functions directly as the mRNA molecule, where as in eukaryotes ___

Answer 33

the RNA must be modified in the nucleus to produce mature mRNA

Question 34

What consists of the modifications in the gene transcript functions of mRNA molecule in eukaryotes ?

Answer 34

additions of a 5’ cap and a 3’ poly (A) trail

removal of any introns

Question 35

In some organisms with introns, the precursor-RNA sequences fold into a secondary structure that excises itself, a process called ___

Answer 35

self-splicing

Question 36

Many RNAs that are edited are encoded by the ___ and __

Answer 36

mitochondrial and chloroplast genomes

Question 37

A protein consists of one or more subunits called ___

Answer 37

polypeptides

Question 38

Polypeptides are composed of ____

Answer 38

amino acids

Question 39

The amino acids are linked together in the polypeptide by ___

Answer 39

peptide bonds

Question 40

In bacteria, the initiation of protein synthesis requires a sequence upstream of the AUG codon, to which the small ribosomal subunit binds. This is known as what ?

Answer 40

Shine-Dalgarno sequence

Question 41

What does the shine-dalgarno sequence do ?

Answer 41

binds specifically to the 3’ end of the 16S rRNA of the small ribosomal unit, thereby associating the small subunit binds

Question 42

In both bacteria and eukaryotes, the initiation of polypeptide synthesis requires protein factors called ?

Answer 42

initiation factors

Question 43

Where are initiation factors found ?

Answer 43

bound to the ribosome-mRNA complex during the initiation phase

Question 44

What are the stop codons ?

Answer 44

UAG UGA UAA