DNA and Biotechnology

Question 1

Nucleosides

Answer 1

contain a five carbon sugar bonded to a nitrogenous base

Question 2

Nucleotides

Answer 2

nucleosides with one to three phosphate groups added

Question 3

Purines

Answer 3

A and G

Question 4

Pyrimidines

Answer 4

C,U,T

Question 5

A pairs with

Answer 5

T in DNA

U in RNA

Question 6

C pairs with

Answer 6

G in DNA and RNA

Question 7

DNA Backbone

Answer 7

composed of alternating sugar and phosphate groups in a 5’-3’ order

Question 8

Chargaff’s Rule

Answer 8

purines and pyrimidines are equal in number in a DNA molecule

Question 9

Denaturing

Answer 9

DNA is pulled apart

Question 10

Reannealed

Answer 10

DNA is brought back together

Question 11

Eukaryotic DNA has ___ chromosomes

Answer 11

46

Question 12

Eukaryotic DNA is wound around _______ to form ____

Answer 12

histone proteins (H2A, H2B, H3, H4) to form nucleosomes

Question 13

Nucleosomes are stabilized by

Answer 13

H1

Question 14

DNA and histones make up

Answer 14

Chromatin in the nucleus

Question 15

Heterochromatin

Answer 15

dense, transcriptionally silent DNA (dark when viewed)

Question 16

Euchromatin

Answer 16

less dense, transcriptionally active DNA (light when viewed)

Question 17

Telemeres

Answer 17

the ends of chromosomes that contain high GC content to prevent DNA unravelling

Question 18

Centromeres

Answer 18

Hold sister chromatids together until they are separated during anaphase in mitosis
also contain high CG content

Question 19

Eukaryotic DNA Replication: Origin

Answer 19

multiple per chromosome

Question 20

Eukaryotic DNA Replication: Unwinding of DNA Double Helix

Answer 20

Helicase

Question 21

Eukaryotic DNA Replication: Stabilization of Unwound Template Strands

Answer 21

Single-stranded DNA binding protein

Question 22

Eukaryotic DNA Replication: Synthesis of RNA primers

Answer 22

Primase

Question 23

Eukaryotic DNA Replication: Synthesis of DNA

Answer 23

DNA polymerases alpha and sigma

Question 24

Eukaryotic DNA Replication: Removal of RNA primers

Answer 24

RNase H (5’-3’ exonuclease)

Question 25

Eukaryotic DNA Replication: Replacement of RNA with DNA

Answer 25

DNA polymerase sigma

Question 26

Eukaryotic DNA Replication: Joining Okazaki Fragments

Answer 26

DNA ligase

Question 27

Eukaryotic DNA Replication: Removal of Positive supercoils ahead of advancing replication forks

Answer 27

DNA topoisomerases

Question 28

Eukaryotic DNA Replication: Synthesis of Telomeres

Answer 28

Telomerase

Question 29

Prokaryotic DNA Replication: Origin of Replication

Answer 29

One per chromosome

Question 30

Prokaryotic DNA Replication: Unwinding of DNA double helix

Answer 30

Helicase

Question 31

Prokaryotic DNA Replication: Stabilization of unwound template strands

Answer 31

Single-stranded DNA-binding protein

Question 32

Prokaryotic DNA Replication: Synthesis of RNA primers

Answer 32

Primase

Question 33

Prokaryotic DNA Replication: Synthesis of DNA

Answer 33

DNA Polymerase III

Question 34

Prokaryotic DNA Replication: Removal of RNA Primers

Answer 34

DNA Polymerase I (5'-3' Exonuclease)

Question 35

Prokaryotic DNA Replication: Replacement of RNA with DNA

Answer 35

DNA polymerase I

Question 36

Prokaryotic DNA Replication: Joining of Okazaki Fragments

Answer 36

DNA ligase

Question 37

Prokaryotic DNA Replication: Removal of positive supercoiled ahead of advancing replication forks

Answer 37

DNA topoisomerase (DNA Gyrase)

Question 38

Semiconservative DNA Replication

Answer 38

one old parent strand and one new daughter strand is incorporated into each of the two new molecules

Question 39

Leading Strand

Answer 39

requires only one primer and can be synthesized continuously

Question 40

Lagging Strand

Answer 40

requires many primers and is synthesized in discrete sections called Okazaki fragments

Question 41

Recombinant DNA

Answer 41

DNA composed of nucleotides from two different sources

Question 42

DNA cloning

Answer 42

introduces a fragment of DNA into a vector plasmid and a restriction enzyme cutes both the plasmid and the fragment, leaving them with stick ends that can bind

Question 43

DNA Libraries

Answer 43

large collections of known DNA sequences

Question 44

Genomic Libraries

Answer 44

Contain large fragments of DNA including introns and exons, cannot be used to make recombinant proteins or for gene therapy

Question 45

cDNA Libraries

Answer 45

aka expression libraries contain smaller fragments of DNA and only include exons of genes expressed by the sample tissue, they can be used to make recombinant proteins or for gene therapy

Question 46

PCR

Answer 46

an automated process by which millions of copies of DNA sequence can be created from a very small sample by hybridization

Question 47

Aragrose Gel Electrophoresis

Answer 47

Can be used to separate DNA molecules by size

Question 48

Southern Blotting

Answer 48

can be used to detect the presence and quality of various DNA strands in a sample. After electrophoresis the sample is transferred to a membrane that can be probed with single-stranded DNA molecules to look for a sequence of interest

Question 49

DNA Sequencing

Answer 49

uses dideoxyribonucleotides with terminate the DNA chain because they lack a 3' -OH group

Question 50

Structure of Purines

Answer 50

2 rings

Question 51

Structure of Pyrimidines

Answer 51

1 ring

Question 52

Histones

Answer 52

DNA is wound around histones to form chromatin, there are 5 histones ( 2-5 are involved in winding, 1 seals off DNA)