DNA and Biotechnology

Question 1

Nucleosides?

Answer 1

contain a five carbon sugar bound to a nitrogenous base

Question 2

Nucleotides?

Answer 2

nucleosides with one to three phosphate groups added

• DNA- deoxyribose
• RNA- ribose

Question 3

Purines?

Answer 3

GA

Question 4

Pyrimidines?

Answer 4

CUT

Question 5

Chargaff’s rule?

Answer 5

purines and pyrimidines are equal in number in DNA, amount of A=T, G=C

Question 6

Denatured strands?

Answer 6

DNA pulled apart

Question 7

Reannealed?

Answer 7

DNA brought back together

Question 8

DNA is organized into ____ chromosomes in human cells.

Answer 8

46

Question 9

DNA is wound around _____ which form _____.

Answer 9

histones (H2A, H2B, H3, H4)

nucleosomes

Question 10

What protein is not part of the histone core and stabilizes nucleosomes?

Answer 10

H1

Question 11

Heterochromatin?

Answer 11

dense, silent DNA

Question 12

Euchromatin?

Answer 12

loose, active DNA

Question 13

Telomeres?

Answer 13

ends of chromosomes, they contain high GC content to prevent unraveling of DNA

Question 14

Centromeres?

Answer 14

located in the middle of chromosomes and hold sister chromatids together until they are separated during anaphase of mitosis, contain high GC content

Question 15

What has multiple origins of replication per chromosome?

Answer 15

Eukaryotes

Question 16

What unwinds the DNA double helix for replication?

Answer 16

helicase

Question 17

What stabilizes the unwound template strands in replication?

Answer 17

single stranded binding proteins

Question 18

What synthesizes RNA primers in replication?

Answer 18

Primase

Question 19

What synthesizes DNA in replication (Prok/Euk)?

Answer 19

Prok- DNA Pol III

Euk- DNA Pol alpha and sigma

Question 20

What removes RNA primers in replication (Prok/Euk)?

Answer 20

Prok- DNA Pol I (5’ to 3’ exonuclease)

Euk- RNAse H (5’ to 3’ exonuclease)

Question 21

What replaces RNA with DNA are removing the RNA primers in replication (Prok/Euk)?

Answer 21

Prok- DNA Pol I

Euk- DNA Pol alpha

Question 22

What joins okazaki fragments?

Answer 22

DNA ligase

Question 23

What removes the positive supercoils induced by helicase?

Answer 23

DNA Topoisomerase II (DNA Gyrase)

Question 24

What synthesizes telomeres?

Answer 24

Telomerase (only in Euk)

Question 25

DNA is synthesized ______ and read ______.

Answer 25

5 to 3

3 to 5

Question 26

How many primers does the leading strand require? lagging?

Answer 26

only one

many

Question 27

Recombinant DNA?

Answer 27

DNA composed of nucleotides from two different sources

Question 28

DNA cloning?

Answer 28

introduce fragment of DNA into a vector plasmid, restriction enzyme (restriction endonucluease) cuts both the plasmid and the fragment leaving them with sticky ends which can bind

Question 29

Genomic libraries?

Answer 29

contain large fragments of DNA, including both the coding and noncoding (introns) regions of the genome, cannot be used to make recombinant proteins or for gene therapy

Question 30

cDNA libraries?

Answer 30

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

Question 31

Hybridization?

Answer 31

the joining of complementary base pair sequences

Question 32

PCR?

Answer 32

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

Question 33

DNA molecules can be separated by size using _____.

Answer 33

agarose gel electrophoresis

Question 34

Southern blotting?

Answer 34

used to detect the presence and quantity of various DNA strand in a sample, looking for a sequence of interest, used after electorphoresis

Question 35

DNA sequencing?

Answer 35

uses dideoxyribonucleotides which terminates the DNA chain b/c they lack a 3’ OH group